Quelle System.java

Sprache: JAVA

/*
* Copyright (c) 1994, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.Console;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.lang.annotation.Annotation;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodType;
import java.lang.invoke.StringConcatFactory;
import java.lang.module.ModuleDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.Executable;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URI;
import java.net.URL;
import java.nio.channels.Channel;
import java.nio.channels.spi.SelectorProvider;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.CodeSource;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Properties;
import java.util.PropertyPermission;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.WeakHashMap;
import java.util.concurrent.Callable;
import java.util.function.Supplier;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Stream;

import jdk.internal.misc.CarrierThreadLocal;
import jdk.internal.misc.Unsafe;
import jdk.internal.util.StaticProperty;
import jdk.internal.module.ModuleBootstrap;
import jdk.internal.module.ServicesCatalog;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
import jdk.internal.access.JavaLangAccess;
import jdk.internal.access.SharedSecrets;
import jdk.internal.misc.VM;
import jdk.internal.logger.LoggerFinderLoader;
import jdk.internal.logger.LazyLoggers;
import jdk.internal.logger.LocalizedLoggerWrapper;
import jdk.internal.util.SystemProps;
import jdk.internal.vm.Continuation;
import jdk.internal.vm.ContinuationScope;
import jdk.internal.vm.StackableScope;
import jdk.internal.vm.ThreadContainer;
import jdk.internal.vm.annotation.ForceInline;
import jdk.internal.vm.annotation.IntrinsicCandidate;
import jdk.internal.vm.annotation.Stable;
import jdk.internal.vm.annotation.ChangesCurrentThread;
import sun.nio.fs.DefaultFileSystemProvider;
import sun.reflect.annotation.AnnotationType;
import sun.nio.ch.Interruptible;
import sun.nio.cs.UTF_8;
import sun.security.util.SecurityConstants;

/**
* The {@code System} class contains several useful class fields
* and methods. It cannot be instantiated.
*
* Among the facilities provided by the {@code System} class
* are standard input, standard output, and error output streams;
* access to externally defined properties and environment
* variables; a means of loading files and libraries; and a utility
* method for quickly copying a portion of an array.
*
* @since 1.0
*/
public final class System {
 /* Register the natives via the static initializer.
 *
 * The VM will invoke the initPhase1 method to complete the initialization
 * of this class separate from <clinit>.
 */
 private static native void registerNatives();
 static {
 registerNatives();
 }

 /** Don't let anyone instantiate this class */
 private System() {
 }

 /**
 * The "standard" input stream. This stream is already
 * open and ready to supply input data. Typically this stream
 * corresponds to keyboard input or another input source specified by
 * the host environment or user. In case this stream is wrapped
 * in a {@link java.io.InputStreamReader}, {@link Console#charset()}
 * should be used for the charset, or consider using
 * {@link Console#reader()}.
 *
 * @see Console#charset()
 * @see Console#reader()
 */
 public static final InputStream in = null;

 /**
 * The "standard" output stream. This stream is already
 * open and ready to accept output data. Typically this stream
 * corresponds to display output or another output destination
 * specified by the host environment or user. The encoding used
 * in the conversion from characters to bytes is equivalent to
 * {@link Console#charset()} if the {@code Console} exists,
 * <a href="#stdout.encoding">stdout.encoding</a> otherwise.
 * 
 * For simple stand-alone Java applications, a typical way to write
 * a line of output data is:
 * <blockquote><pre>
 * System.out.println(data)
 * </pre></blockquote>
 * 
 * See the {@code println} methods in class {@code PrintStream}.
 *
 * @see java.io.PrintStream#println()
 * @see java.io.PrintStream#println(boolean)
 * @see java.io.PrintStream#println(char)
 * @see java.io.PrintStream#println(char[])
 * @see java.io.PrintStream#println(double)
 * @see java.io.PrintStream#println(float)
 * @see java.io.PrintStream#println(int)
 * @see java.io.PrintStream#println(long)
 * @see java.io.PrintStream#println(java.lang.Object)
 * @see java.io.PrintStream#println(java.lang.String)
 * @see Console#charset()
 * @see <a href="#stdout.encoding">stdout.encoding</a>
 */
 public static final PrintStream out = null;

 /**
 * The "standard" error output stream. This stream is already
 * open and ready to accept output data.
 * 
 * Typically this stream corresponds to display output or another
 * output destination specified by the host environment or user. By
 * convention, this output stream is used to display error messages
 * or other information that should come to the immediate attention
 * of a user even if the principal output stream, the value of the
 * variable {@code out}, has been redirected to a file or other
 * destination that is typically not continuously monitored.
 * The encoding used in the conversion from characters to bytes is
 * equivalent to {@link Console#charset()} if the {@code Console}
 * exists, <a href="#stderr.encoding">stderr.encoding</a> otherwise.
 *
 * @see Console#charset()
 * @see <a href="#stderr.encoding">stderr.encoding</a>
 */
 public static final PrintStream err = null;

 // Holder for the initial value of `in`, set within `initPhase1()`.
 private static InputStream initialIn;

 // indicates if a security manager is possible
 private static final int NEVER = 1;
 private static final int MAYBE = 2;
 private static @Stable int allowSecurityManager;

 // current security manager
 @SuppressWarnings("removal")
 private static volatile SecurityManager security; // read by VM

 // `sun.jnu.encoding` if it is not supported. Otherwise null.
 // It is initialized in `initPhase1()` before any charset providers
 // are initialized.
 private static String notSupportedJnuEncoding;

 // return true if a security manager is allowed
 private static boolean allowSecurityManager() {
 return (allowSecurityManager != NEVER);
 }

 /**
 * Reassigns the "standard" input stream.
 *
 * First, if there is a security manager, its {@code checkPermission}
 * method is called with a {@code RuntimePermission("setIO")} permission
 * to see if it's ok to reassign the "standard" input stream.
 *
 * @param in the new standard input stream.
 *
 * @throws SecurityException
 * if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * reassigning of the standard input stream.
 *
 * @see SecurityManager#checkPermission
 * @see java.lang.RuntimePermission
 *
 * @since 1.1
 */
 public static void setIn(InputStream in) {
 checkIO();
 setIn0(in);
 }

 /**
 * Reassigns the "standard" output stream.
 *
 * First, if there is a security manager, its {@code checkPermission}
 * method is called with a {@code RuntimePermission("setIO")} permission
 * to see if it's ok to reassign the "standard" output stream.
 *
 * @param out the new standard output stream
 *
 * @throws SecurityException
 * if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * reassigning of the standard output stream.
 *
 * @see SecurityManager#checkPermission
 * @see java.lang.RuntimePermission
 *
 * @since 1.1
 */
 public static void setOut(PrintStream out) {
 checkIO();
 setOut0(out);
 }

 /**
 * Reassigns the "standard" error output stream.
 *
 * First, if there is a security manager, its {@code checkPermission}
 * method is called with a {@code RuntimePermission("setIO")} permission
 * to see if it's ok to reassign the "standard" error output stream.
 *
 * @param err the new standard error output stream.
 *
 * @throws SecurityException
 * if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * reassigning of the standard error output stream.
 *
 * @see SecurityManager#checkPermission
 * @see java.lang.RuntimePermission
 *
 * @since 1.1
 */
 public static void setErr(PrintStream err) {
 checkIO();
 setErr0(err);
 }

 private static volatile Console cons;

 /**
 * Returns the unique {@link java.io.Console Console} object associated
 * with the current Java virtual machine, if any.
 *
 * @return The system console, if any, otherwise {@code null}.
 *
 * @since 1.6
 */
 public static Console console() {
 Console c;
 if ((c = cons) == null) {
 synchronized (System.class) {
 if ((c = cons) == null) {
 cons = c = SharedSecrets.getJavaIOAccess().console();
 }
 }
 }
 return c;
 }

 /**
 * Returns the channel inherited from the entity that created this
 * Java virtual machine.
 *
 * This method returns the channel obtained by invoking the
 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
 * inheritedChannel} method of the system-wide default
 * {@link java.nio.channels.spi.SelectorProvider} object.
 *
 * In addition to the network-oriented channels described in
 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
 * inheritedChannel}, this method may return other kinds of
 * channels in the future.
 *
 * @return The inherited channel, if any, otherwise {@code null}.
 *
 * @throws IOException
 * If an I/O error occurs
 *
 * @throws SecurityException
 * If a security manager is present and it does not
 * permit access to the channel.
 *
 * @since 1.5
 */
 public static Channel inheritedChannel() throws IOException {
 return SelectorProvider.provider().inheritedChannel();
 }

 private static void checkIO() {
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPermission(new RuntimePermission("setIO"));
 }
 }

 private static native void setIn0(InputStream in);
 private static native void setOut0(PrintStream out);
 private static native void setErr0(PrintStream err);

 private static class CallersHolder {
 // Remember callers of setSecurityManager() here so that warning
 // is only printed once for each different caller
 static final Map<Class<?>, Boolean> callers
 = Collections.synchronizedMap(new WeakHashMap<>());
 }

 // Remember initial System.err. setSecurityManager() warning goes here
 private static volatile @Stable PrintStream initialErrStream;

 private static URL codeSource(Class<?> clazz) {
 PrivilegedAction<ProtectionDomain> pa = clazz::getProtectionDomain;
 @SuppressWarnings("removal")
 CodeSource cs = AccessController.doPrivileged(pa).getCodeSource();
 return (cs != null) ? cs.getLocation() : null;
 }

 /**
 * Sets the system-wide security manager.
 *
 * If there is a security manager already installed, this method first
 * calls the security manager's {@code checkPermission} method
 * with a {@code RuntimePermission("setSecurityManager")}
 * permission to ensure it's ok to replace the existing
 * security manager.
 * This may result in throwing a {@code SecurityException}.
 *
 * Otherwise, the argument is established as the current
 * security manager. If the argument is {@code null} and no
 * security manager has been established, then no action is taken and
 * the method simply returns.
 *
 * @implNote In the JDK implementation, if the Java virtual machine is
 * started with the system property {@code java.security.manager} not set or set to
 * the special token "{@code disallow}" then the {@code setSecurityManager}
 * method cannot be used to set a security manager. See the following
 * <a href="SecurityManager.html#set-security-manager">section of the
 * {@code SecurityManager} class specification</a> for more details.
 *
 * @param sm the security manager or {@code null}
 * @throws SecurityException
 * if the security manager has already been set and its {@code
 * checkPermission} method doesn't allow it to be replaced
 * @throws UnsupportedOperationException
 * if {@code sm} is non-null and a security manager is not allowed
 * to be set dynamically
 * @see #getSecurityManager
 * @see SecurityManager#checkPermission
 * @see java.lang.RuntimePermission
 * @deprecated This method is only useful in conjunction with
 * {@linkplain SecurityManager the Security Manager}, which is
 * deprecated and subject to removal in a future release.
 * Consequently, this method is also deprecated and subject to
 * removal. There is no replacement for the Security Manager or this
 * method.
 */
 @Deprecated(since="17", forRemoval=true)
 @CallerSensitive
 public static void setSecurityManager(@SuppressWarnings("removal") SecurityManager sm) {
 if (allowSecurityManager()) {
 var callerClass = Reflection.getCallerClass();
 if (CallersHolder.callers.putIfAbsent(callerClass, true) == null) {
 URL url = codeSource(callerClass);
 final String source;
 if (url == null) {
 source = callerClass.getName();
 } else {
 source = callerClass.getName() + " (" + url + ")";
 }
 initialErrStream.printf("""
 WARNING: A terminally deprecated method in java.lang.System has been called
 WARNING: System::setSecurityManager has been called by %s
 WARNING: Please consider reporting this to the maintainers of %s
 WARNING: System::setSecurityManager will be removed in a future release
 """, source, callerClass.getName());
 }
 implSetSecurityManager(sm);
 } else {
 // security manager not allowed
 if (sm != null) {
 throw new UnsupportedOperationException(
 "The Security Manager is deprecated and will be removed in a future release");
 }
 }
 }

 private static void implSetSecurityManager(@SuppressWarnings("removal") SecurityManager sm) {
 if (security == null) {
 // ensure image reader is initialized
 Object.class.getResource("java/lang/ANY");
 // ensure the default file system is initialized
 DefaultFileSystemProvider.theFileSystem();
 }
 if (sm != null) {
 try {
 // pre-populates the SecurityManager.packageAccess cache
 // to avoid recursive permission checking issues with custom
 // SecurityManager implementations
 sm.checkPackageAccess("java.lang");
 } catch (Exception e) {
 // no-op
 }
 }
 setSecurityManager0(sm);
 }

 @SuppressWarnings("removal")
 private static synchronized
 void setSecurityManager0(final SecurityManager s) {
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 // ask the currently installed security manager if we
 // can replace it.
 sm.checkPermission(new RuntimePermission("setSecurityManager"));
 }

 if ((s != null) && (s.getClass().getClassLoader() != null)) {
 // New security manager class is not on bootstrap classpath.
 // Force policy to get initialized before we install the new
 // security manager, in order to prevent infinite loops when
 // trying to initialize the policy (which usually involves
 // accessing some security and/or system properties, which in turn
 // calls the installed security manager's checkPermission method
 // which will loop infinitely if there is a non-system class
 // (in this case: the new security manager class) on the stack).
 AccessController.doPrivileged(new PrivilegedAction<>() {
 public Object run() {
 s.getClass().getProtectionDomain().implies
 (SecurityConstants.ALL_PERMISSION);
 return null;
 }
 });
 }

 security = s;
 }

 /**
 * Gets the system-wide security manager.
 *
 * @return if a security manager has already been established for the
 * current application, then that security manager is returned;
 * otherwise, {@code null} is returned.
 * @see #setSecurityManager
 * @deprecated This method is only useful in conjunction with
 * {@linkplain SecurityManager the Security Manager}, which is
 * deprecated and subject to removal in a future release.
 * Consequently, this method is also deprecated and subject to
 * removal. There is no replacement for the Security Manager or this
 * method.
 */
 @SuppressWarnings("removal")
 @Deprecated(since="17", forRemoval=true)
 public static SecurityManager getSecurityManager() {
 if (allowSecurityManager()) {
 return security;
 } else {
 return null;
 }
 }

 /**
 * Returns the current time in milliseconds. Note that
 * while the unit of time of the return value is a millisecond,
 * the granularity of the value depends on the underlying
 * operating system and may be larger. For example, many
 * operating systems measure time in units of tens of
 * milliseconds.
 *
 * See the description of the class {@code Date} for
 * a discussion of slight discrepancies that may arise between
 * "computer time" and coordinated universal time (UTC).
 *
 * @return the difference, measured in milliseconds, between
 * the current time and midnight, January 1, 1970 UTC.
 * @see java.util.Date
 */
 @IntrinsicCandidate
 public static native long currentTimeMillis();

 /**
 * Returns the current value of the running Java Virtual Machine's
 * high-resolution time source, in nanoseconds.
 *
 * This method can only be used to measure elapsed time and is
 * not related to any other notion of system or wall-clock time.
 * The value returned represents nanoseconds since some fixed but
 * arbitrary origin time (perhaps in the future, so values
 * may be negative). The same origin is used by all invocations of
 * this method in an instance of a Java virtual machine; other
 * virtual machine instances are likely to use a different origin.
 *
 * This method provides nanosecond precision, but not necessarily
 * nanosecond resolution (that is, how frequently the value changes)
 * - no guarantees are made except that the resolution is at least as
 * good as that of {@link #currentTimeMillis()}.
 *
 * Differences in successive calls that span greater than
 * approximately 292 years (263 nanoseconds) will not
 * correctly compute elapsed time due to numerical overflow.
 *
 * The values returned by this method become meaningful only when
 * the difference between two such values, obtained within the same
 * instance of a Java virtual machine, is computed.
 *
 * For example, to measure how long some code takes to execute:
 * <pre> {@code
 * long startTime = System.nanoTime();
 * // ... the code being measured ...
 * long elapsedNanos = System.nanoTime() - startTime;}</pre>
 *
 * To compare elapsed time against a timeout, use <pre> {@code
 * if (System.nanoTime() - startTime >= timeoutNanos) ...}</pre>
 * instead of <pre> {@code
 * if (System.nanoTime() >= startTime + timeoutNanos) ...}</pre>
 * because of the possibility of numerical overflow.
 *
 * @return the current value of the running Java Virtual Machine's
 * high-resolution time source, in nanoseconds
 * @since 1.5
 */
 @IntrinsicCandidate
 public static native long nanoTime();

 /**
 * Copies an array from the specified source array, beginning at the
 * specified position, to the specified position of the destination array.
 * A subsequence of array components are copied from the source
 * array referenced by {@code src} to the destination array
 * referenced by {@code dest}. The number of components copied is
 * equal to the {@code length} argument. The components at
 * positions {@code srcPos} through
 * {@code srcPos+length-1} in the source array are copied into
 * positions {@code destPos} through
 * {@code destPos+length-1}, respectively, of the destination
 * array.
 * 
 * If the {@code src} and {@code dest} arguments refer to the
 * same array object, then the copying is performed as if the
 * components at positions {@code srcPos} through
 * {@code srcPos+length-1} were first copied to a temporary
 * array with {@code length} components and then the contents of
 * the temporary array were copied into positions
 * {@code destPos} through {@code destPos+length-1} of the
 * destination array.
 * 
 * If {@code dest} is {@code null}, then a
 * {@code NullPointerException} is thrown.
 * 
 * If {@code src} is {@code null}, then a
 * {@code NullPointerException} is thrown and the destination
 * array is not modified.
 * 
 * Otherwise, if any of the following is true, an
 * {@code ArrayStoreException} is thrown and the destination is
 * not modified:
 * <ul>
 * <li>The {@code src} argument refers to an object that is not an
 * array.
 * <li>The {@code dest} argument refers to an object that is not an
 * array.
 * <li>The {@code src} argument and {@code dest} argument refer
 * to arrays whose component types are different primitive types.
 * <li>The {@code src} argument refers to an array with a primitive
 * component type and the {@code dest} argument refers to an array
 * with a reference component type.
 * <li>The {@code src} argument refers to an array with a reference
 * component type and the {@code dest} argument refers to an array
 * with a primitive component type.
 * </ul>
 * 
 * Otherwise, if any of the following is true, an
 * {@code IndexOutOfBoundsException} is
 * thrown and the destination is not modified:
 * <ul>
 * <li>The {@code srcPos} argument is negative.
 * <li>The {@code destPos} argument is negative.
 * <li>The {@code length} argument is negative.
 * <li>{@code srcPos+length} is greater than
 * {@code src.length}, the length of the source array.
 * <li>{@code destPos+length} is greater than
 * {@code dest.length}, the length of the destination array.
 * </ul>
 * 
 * Otherwise, if any actual component of the source array from
 * position {@code srcPos} through
 * {@code srcPos+length-1} cannot be converted to the component
 * type of the destination array by assignment conversion, an
 * {@code ArrayStoreException} is thrown. In this case, let
 * k be the smallest nonnegative integer less than
 * length such that {@code src[srcPos+}k{@code ]}
 * cannot be converted to the component type of the destination
 * array; when the exception is thrown, source array components from
 * positions {@code srcPos} through
 * {@code srcPos+}k{@code -1}
 * will already have been copied to destination array positions
 * {@code destPos} through
 * {@code destPos+}k{@code -1} and no other
 * positions of the destination array will have been modified.
 * (Because of the restrictions already itemized, this
 * paragraph effectively applies only to the situation where both
 * arrays have component types that are reference types.)
 *
 * @param src the source array.
 * @param srcPos starting position in the source array.
 * @param dest the destination array.
 * @param destPos starting position in the destination data.
 * @param length the number of array elements to be copied.
 * @throws IndexOutOfBoundsException if copying would cause
 * access of data outside array bounds.
 * @throws ArrayStoreException if an element in the {@code src}
 * array could not be stored into the {@code dest} array
 * because of a type mismatch.
 * @throws NullPointerException if either {@code src} or
 * {@code dest} is {@code null}.
 */
 @IntrinsicCandidate
 public static native void arraycopy(Object src, int srcPos,
 Object dest, int destPos,
 int length);

 /**
 * Returns the same hash code for the given object as
 * would be returned by the default method hashCode(),
 * whether or not the given object's class overrides
 * hashCode().
 * The hash code for the null reference is zero.
 *
 * @param x object for which the hashCode is to be calculated
 * @return the hashCode
 * @since 1.1
 * @see Object#hashCode
 * @see java.util.Objects#hashCode(Object)
 */
 @IntrinsicCandidate
 public static native int identityHashCode(Object x);

 /**
 * System properties.
 *
 * See {@linkplain #getProperties getProperties} for details.
 */
 private static Properties props;

 /**
 * Determines the current system properties.
 *
 * First, if there is a security manager, its
 * {@code checkPropertiesAccess} method is called with no
 * arguments. This may result in a security exception.
 * 
 * The current set of system properties for use by the
 * {@link #getProperty(String)} method is returned as a
 * {@code Properties} object. If there is no current set of
 * system properties, a set of system properties is first created and
 * initialized. This set of system properties includes a value
 * for each of the following keys unless the description of the associated
 * value indicates that the value is optional.
 * <table class="striped" style="text-align:left">
 * <caption style="display:none">Shows property keys and associated values</caption>
 * <thead>
 * <tr><th scope="col">Key</th>
 * <th scope="col">Description of Associated Value</th></tr>
 * </thead>
 * <tbody>
 * <tr><th scope="row">{@systemProperty java.version}</th>
 * <td>Java Runtime Environment version, which may be interpreted
 * as a {@link Runtime.Version}</td></tr>
 * <tr><th scope="row">{@systemProperty java.version.date}</th>
 * <td>Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD
 * format, which may be interpreted as a {@link
 * java.time.LocalDate}</td></tr>
 * <tr><th scope="row">{@systemProperty java.vendor}</th>
 * <td>Java Runtime Environment vendor</td></tr>
 * <tr><th scope="row">{@systemProperty java.vendor.url}</th>
 * <td>Java vendor URL</td></tr>
 * <tr><th scope="row">{@systemProperty java.vendor.version}</th>
 * <td>Java vendor version (optional) </td></tr>
 * <tr><th scope="row">{@systemProperty java.home}</th>
 * <td>Java installation directory</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.specification.version}</th>
 * <td>Java Virtual Machine specification version, whose value is the
 * {@linkplain Runtime.Version#feature feature} element of the
 * {@linkplain Runtime#version() runtime version}</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.specification.vendor}</th>
 * <td>Java Virtual Machine specification vendor</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.specification.name}</th>
 * <td>Java Virtual Machine specification name</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.version}</th>
 * <td>Java Virtual Machine implementation version which may be
 * interpreted as a {@link Runtime.Version}</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.vendor}</th>
 * <td>Java Virtual Machine implementation vendor</td></tr>
 * <tr><th scope="row">{@systemProperty java.vm.name}</th>
 * <td>Java Virtual Machine implementation name</td></tr>
 * <tr><th scope="row">{@systemProperty java.specification.version}</th>
 * <td>Java Runtime Environment specification version, whose value is
 * the {@linkplain Runtime.Version#feature feature} element of the
 * {@linkplain Runtime#version() runtime version}</td></tr>
 * <tr><th scope="row">{@systemProperty java.specification.maintenance.version}</th>
 * <td>Java Runtime Environment specification maintenance version,
 * may be interpreted as a positive integer (optional, see below)</td></tr>
 * <tr><th scope="row">{@systemProperty java.specification.vendor}</th>
 * <td>Java Runtime Environment specification vendor</td></tr>
 * <tr><th scope="row">{@systemProperty java.specification.name}</th>
 * <td>Java Runtime Environment specification name</td></tr>
 * <tr><th scope="row">{@systemProperty java.class.version}</th>
 * <td>Java class format version number</td></tr>
 * <tr><th scope="row">{@systemProperty java.class.path}</th>
 * <td>Java class path (refer to
 * {@link ClassLoader#getSystemClassLoader()} for details)</td></tr>
 * <tr><th scope="row">{@systemProperty java.library.path}</th>
 * <td>List of paths to search when loading libraries</td></tr>
 * <tr><th scope="row">{@systemProperty java.io.tmpdir}</th>
 * <td>Default temp file path</td></tr>
 * <tr><th scope="row">{@systemProperty java.compiler}</th>
 * <td>Name of JIT compiler to use</td></tr>
 * <tr><th scope="row">{@systemProperty os.name}</th>
 * <td>Operating system name</td></tr>
 * <tr><th scope="row">{@systemProperty os.arch}</th>
 * <td>Operating system architecture</td></tr>
 * <tr><th scope="row">{@systemProperty os.version}</th>
 * <td>Operating system version</td></tr>
 * <tr><th scope="row">{@systemProperty file.separator}</th>
 * <td>File separator ("/" on UNIX)</td></tr>
 * <tr><th scope="row">{@systemProperty path.separator}</th>
 * <td>Path separator (":" on UNIX)</td></tr>
 * <tr><th scope="row">{@systemProperty line.separator}</th>
 * <td>Line separator ("\n" on UNIX)</td></tr>
 * <tr><th scope="row">{@systemProperty user.name}</th>
 * <td>User's account name</td></tr>
 * <tr><th scope="row">{@systemProperty user.home}</th>
 * <td>User's home directory</td></tr>
 * <tr><th scope="row">{@systemProperty user.dir}</th>
 * <td>User's current working directory</td></tr>
 * <tr><th scope="row">{@systemProperty native.encoding}</th>
 * <td>Character encoding name derived from the host environment and/or
 * the user's settings. Setting this system property has no effect.</td></tr>
 * <tr><th scope="row">{@systemProperty stdout.encoding}</th>
 * <td>Character encoding name for {@link System#out System.out}.
 * The Java runtime can be started with the system property set to {@code UTF-8},
 * starting it with the property set to another value leads to undefined behavior.
 * <tr><th scope="row">{@systemProperty stderr.encoding}</th>
 * <td>Character encoding name for {@link System#err System.err}.
 * The Java runtime can be started with the system property set to {@code UTF-8},
 * starting it with the property set to another value leads to undefined behavior.
 * </tbody>
 * </table>
 * 
 * The {@code java.specification.maintenance.version} property is
 * defined if the specification implemented by this runtime at the
 * time of its construction had undergone a <a
 * href="https://jcp.org/en/procedures/jcp2#3.6.4">maintenance
 * release</a>. When defined, its value identifies that
 * maintenance release. To indicate the first maintenance release
 * this property will have the value {@code "1"}, to indicate the
 * second maintenance release this property will have the value
 * {@code "2"}, and so on.
 * 
 * Multiple paths in a system property value are separated by the path
 * separator character of the platform.
 * 
 * Note that even if the security manager does not permit the
 * {@code getProperties} operation, it may choose to permit the
 * {@link #getProperty(String)} operation.
 *
 * @apiNote
 * Changing a standard system property may have unpredictable results
 * unless otherwise specified.
 * Property values may be cached during initialization or on first use.
 * Setting a standard property after initialization using {@link #getProperties()},
 * {@link #setProperties(Properties)}, {@link #setProperty(String, String)}, or
 * {@link #clearProperty(String)} may not have the desired effect.
 *
 * @implNote
 * In addition to the standard system properties, the system
 * properties may include the following keys:
 * <table class="striped">
 * <caption style="display:none">Shows property keys and associated values</caption>
 * <thead>
 * <tr><th scope="col">Key</th>
 * <th scope="col">Description of Associated Value</th></tr>
 * </thead>
 * <tbody>
 * <tr><th scope="row">{@systemProperty jdk.module.path}</th>
 * <td>The application module path</td></tr>
 * <tr><th scope="row">{@systemProperty jdk.module.upgrade.path}</th>
 * <td>The upgrade module path</td></tr>
 * <tr><th scope="row">{@systemProperty jdk.module.main}</th>
 * <td>The module name of the initial/main module</td></tr>
 * <tr><th scope="row">{@systemProperty jdk.module.main.class}</th>
 * <td>The main class name of the initial module</td></tr>
 * <tr><th scope="row">{@systemProperty file.encoding}</th>
 * <td>The name of the default charset, defaults to {@code UTF-8}.
 * The property may be set on the command line to the value
 * {@code UTF-8} or {@code COMPAT}. If set on the command line to
 * the value {@code COMPAT} then the value is replaced with the
 * value of the {@code native.encoding} property during startup.
 * Setting the property to a value other than {@code UTF-8} or
 * {@code COMPAT} leads to unspecified behavior.
 * </td></tr>
 * </tbody>
 * </table>
 *
 * @return the system properties
 * @throws SecurityException if a security manager exists and its
 * {@code checkPropertiesAccess} method doesn't allow access
 * to the system properties.
 * @see #setProperties
 * @see java.lang.SecurityException
 * @see java.lang.SecurityManager#checkPropertiesAccess()
 * @see java.util.Properties
 */
 public static Properties getProperties() {
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPropertiesAccess();
 }

 return props;
 }

 /**
 * Returns the system-dependent line separator string. It always
 * returns the same value - the initial value of the {@linkplain
 * #getProperty(String) system property} {@code line.separator}.
 *
 * On UNIX systems, it returns {@code "\n"}; on Microsoft
 * Windows systems it returns {@code "\r\n"}.
 *
 * @return the system-dependent line separator string
 * @since 1.7
 */
 public static String lineSeparator() {
 return lineSeparator;
 }

 private static String lineSeparator;

 /**
 * Sets the system properties to the {@code Properties} argument.
 *
 * First, if there is a security manager, its
 * {@code checkPropertiesAccess} method is called with no
 * arguments. This may result in a security exception.
 * 
 * The argument becomes the current set of system properties for use
 * by the {@link #getProperty(String)} method. If the argument is
 * {@code null}, then the current set of system properties is
 * forgotten.
 *
 * @apiNote
 * Changing a standard system property may have unpredictable results
 * unless otherwise specified.
 * See {@linkplain #getProperties getProperties} for details.
 *
 * @param props the new system properties.
 * @throws SecurityException if a security manager exists and its
 * {@code checkPropertiesAccess} method doesn't allow access
 * to the system properties.
 * @see #getProperties
 * @see java.util.Properties
 * @see java.lang.SecurityException
 * @see java.lang.SecurityManager#checkPropertiesAccess()
 */
 public static void setProperties(Properties props) {
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPropertiesAccess();
 }

 if (props == null) {
 Map<String, String> tempProps = SystemProps.initProperties();
 VersionProps.init(tempProps);
 props = createProperties(tempProps);
 }
 System.props = props;
 }

 /**
 * Gets the system property indicated by the specified key.
 *
 * First, if there is a security manager, its
 * {@code checkPropertyAccess} method is called with the key as
 * its argument. This may result in a SecurityException.
 * 
 * If there is no current set of system properties, a set of system
 * properties is first created and initialized in the same manner as
 * for the {@code getProperties} method.
 *
 * @apiNote
 * Changing a standard system property may have unpredictable results
 * unless otherwise specified.
 * See {@linkplain #getProperties getProperties} for details.
 *
 * @param key the name of the system property.
 * @return the string value of the system property,
 * or {@code null} if there is no property with that key.
 *
 * @throws SecurityException if a security manager exists and its
 * {@code checkPropertyAccess} method doesn't allow
 * access to the specified system property.
 * @throws NullPointerException if {@code key} is {@code null}.
 * @throws IllegalArgumentException if {@code key} is empty.
 * @see #setProperty
 * @see java.lang.SecurityException
 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
 * @see java.lang.System#getProperties()
 */
 public static String getProperty(String key) {
 checkKey(key);
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPropertyAccess(key);
 }

 return props.getProperty(key);
 }

 /**
 * Gets the system property indicated by the specified key.
 *
 * First, if there is a security manager, its
 * {@code checkPropertyAccess} method is called with the
 * {@code key} as its argument.
 * 
 * If there is no current set of system properties, a set of system
 * properties is first created and initialized in the same manner as
 * for the {@code getProperties} method.
 *
 * @param key the name of the system property.
 * @param def a default value.
 * @return the string value of the system property,
 * or the default value if there is no property with that key.
 *
 * @throws SecurityException if a security manager exists and its
 * {@code checkPropertyAccess} method doesn't allow
 * access to the specified system property.
 * @throws NullPointerException if {@code key} is {@code null}.
 * @throws IllegalArgumentException if {@code key} is empty.
 * @see #setProperty
 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
 * @see java.lang.System#getProperties()
 */
 public static String getProperty(String key, String def) {
 checkKey(key);
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPropertyAccess(key);
 }

 return props.getProperty(key, def);
 }

 /**
 * Sets the system property indicated by the specified key.
 *
 * First, if a security manager exists, its
 * {@code SecurityManager.checkPermission} method
 * is called with a {@code PropertyPermission(key, "write")}
 * permission. This may result in a SecurityException being thrown.
 * If no exception is thrown, the specified property is set to the given
 * value.
 *
 * @apiNote
 * Changing a standard system property may have unpredictable results
 * unless otherwise specified.
 * See {@linkplain #getProperties getProperties} for details.
 *
 * @param key the name of the system property.
 * @param value the value of the system property.
 * @return the previous value of the system property,
 * or {@code null} if it did not have one.
 *
 * @throws SecurityException if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * setting of the specified property.
 * @throws NullPointerException if {@code key} or
 * {@code value} is {@code null}.
 * @throws IllegalArgumentException if {@code key} is empty.
 * @see #getProperty
 * @see java.lang.System#getProperty(java.lang.String)
 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
 * @see java.util.PropertyPermission
 * @see SecurityManager#checkPermission
 * @since 1.2
 */
 public static String setProperty(String key, String value) {
 checkKey(key);
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPermission(new PropertyPermission(key,
 SecurityConstants.PROPERTY_WRITE_ACTION));
 }

 return (String) props.setProperty(key, value);
 }

 /**
 * Removes the system property indicated by the specified key.
 *
 * First, if a security manager exists, its
 * {@code SecurityManager.checkPermission} method
 * is called with a {@code PropertyPermission(key, "write")}
 * permission. This may result in a SecurityException being thrown.
 * If no exception is thrown, the specified property is removed.
 *
 * @apiNote
 * Changing a standard system property may have unpredictable results
 * unless otherwise specified.
 * See {@linkplain #getProperties getProperties} method for details.
 *
 * @param key the name of the system property to be removed.
 * @return the previous string value of the system property,
 * or {@code null} if there was no property with that key.
 *
 * @throws SecurityException if a security manager exists and its
 * {@code checkPropertyAccess} method doesn't allow
 * access to the specified system property.
 * @throws NullPointerException if {@code key} is {@code null}.
 * @throws IllegalArgumentException if {@code key} is empty.
 * @see #getProperty
 * @see #setProperty
 * @see java.util.Properties
 * @see java.lang.SecurityException
 * @see java.lang.SecurityManager#checkPropertiesAccess()
 * @since 1.5
 */
 public static String clearProperty(String key) {
 checkKey(key);
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPermission(new PropertyPermission(key, "write"));
 }

 return (String) props.remove(key);
 }

 private static void checkKey(String key) {
 if (key == null) {
 throw new NullPointerException("key can't be null");
 }
 if (key.isEmpty()) {
 throw new IllegalArgumentException("key can't be empty");
 }
 }

 /**
 * Gets the value of the specified environment variable. An
 * environment variable is a system-dependent external named
 * value.
 *
 * If a security manager exists, its
 * {@link SecurityManager#checkPermission checkPermission}
 * method is called with a
 * {@link RuntimePermission RuntimePermission("getenv."+name)}
 * permission. This may result in a {@link SecurityException}
 * being thrown. If no exception is thrown the value of the
 * variable {@code name} is returned.
 *
 * <a id="EnvironmentVSSystemProperties">System
 * properties and environment variables</a> are both
 * conceptually mappings between names and values. Both
 * mechanisms can be used to pass user-defined information to a
 * Java process. Environment variables have a more global effect,
 * because they are visible to all descendants of the process
 * which defines them, not just the immediate Java subprocess.
 * They can have subtly different semantics, such as case
 * insensitivity, on different operating systems. For these
 * reasons, environment variables are more likely to have
 * unintended side effects. It is best to use system properties
 * where possible. Environment variables should be used when a
 * global effect is desired, or when an external system interface
 * requires an environment variable (such as {@code PATH}).
 *
 * On UNIX systems the alphabetic case of {@code name} is
 * typically significant, while on Microsoft Windows systems it is
 * typically not. For example, the expression
 * {@code System.getenv("FOO").equals(System.getenv("foo"))}
 * is likely to be true on Microsoft Windows.
 *
 * @param name the name of the environment variable
 * @return the string value of the variable, or {@code null}
 * if the variable is not defined in the system environment
 * @throws NullPointerException if {@code name} is {@code null}
 * @throws SecurityException
 * if a security manager exists and its
 * {@link SecurityManager#checkPermission checkPermission}
 * method doesn't allow access to the environment variable
 * {@code name}
 * @see #getenv()
 * @see ProcessBuilder#environment()
 */
 public static String getenv(String name) {
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPermission(new RuntimePermission("getenv."+name));
 }

 return ProcessEnvironment.getenv(name);
 }

 /**
 * Returns an unmodifiable string map view of the current system environment.
 * The environment is a system-dependent mapping from names to
 * values which is passed from parent to child processes.
 *
 * If the system does not support environment variables, an
 * empty map is returned.
 *
 * The returned map will never contain null keys or values.
 * Attempting to query the presence of a null key or value will
 * throw a {@link NullPointerException}. Attempting to query
 * the presence of a key or value which is not of type
 * {@link String} will throw a {@link ClassCastException}.
 *
 * The returned map and its collection views may not obey the
 * general contract of the {@link Object#equals} and
 * {@link Object#hashCode} methods.
 *
 * The returned map is typically case-sensitive on all platforms.
 *
 * If a security manager exists, its
 * {@link SecurityManager#checkPermission checkPermission}
 * method is called with a
 * {@link RuntimePermission RuntimePermission("getenv.*")} permission.
 * This may result in a {@link SecurityException} being thrown.
 *
 * When passing information to a Java subprocess,
 * <a href=#EnvironmentVSSystemProperties>system properties</a>
 * are generally preferred over environment variables.
 *
 * @return the environment as a map of variable names to values
 * @throws SecurityException
 * if a security manager exists and its
 * {@link SecurityManager#checkPermission checkPermission}
 * method doesn't allow access to the process environment
 * @see #getenv(String)
 * @see ProcessBuilder#environment()
 * @since 1.5
 */
 public static java.util.Map<String,String> getenv() {
 @SuppressWarnings("removal")
 SecurityManager sm = getSecurityManager();
 if (sm != null) {
 sm.checkPermission(new RuntimePermission("getenv.*"));
 }

 return ProcessEnvironment.getenv();
 }

 /**
 * {@code System.Logger} instances log messages that will be
 * routed to the underlying logging framework the {@link System.LoggerFinder
 * LoggerFinder} uses.
 *
 * {@code System.Logger} instances are typically obtained from
 * the {@link java.lang.System System} class, by calling
 * {@link java.lang.System#getLogger(java.lang.String) System.getLogger(loggerName)}
 * or {@link java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
 * System.getLogger(loggerName, bundle)}.
 *
 * @see java.lang.System#getLogger(java.lang.String)
 * @see java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
 * @see java.lang.System.LoggerFinder
 *
 * @since 9
 */
 public interface Logger {

 /**
 * System {@linkplain Logger loggers} levels.
 *
 * A level has a {@linkplain #getName() name} and {@linkplain
 * #getSeverity() severity}.
 * Level values are {@link #ALL}, {@link #TRACE}, {@link #DEBUG},
 * {@link #INFO}, {@link #WARNING}, {@link #ERROR}, {@link #OFF},
 * by order of increasing severity.
 * 
 * {@link #ALL} and {@link #OFF}
 * are simple markers with severities mapped respectively to
 * {@link java.lang.Integer#MIN_VALUE Integer.MIN_VALUE} and
 * {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
 * 
 * Severity values and Mapping to {@code java.util.logging.Level}.
 * 
 * {@linkplain System.Logger.Level System logger levels} are mapped to
 * {@linkplain java.logging/java.util.logging.Level java.util.logging levels}
 * of corresponding severity.
 * The mapping is as follows:
 * 
 * <table class="striped">
 * <caption>System.Logger Severity Level Mapping</caption>
 * <thead>
 * <tr><th scope="col">System.Logger Levels</th>
 * <th scope="col">java.util.logging Levels</th>
 * </thead>
 * <tbody>
 * <tr><th scope="row">{@link Logger.Level#ALL ALL}</th>
 * <td>{@link java.logging/java.util.logging.Level#ALL ALL}</td>
 * <tr><th scope="row">{@link Logger.Level#TRACE TRACE}</th>
 * <td>{@link java.logging/java.util.logging.Level#FINER FINER}</td>
 * <tr><th scope="row">{@link Logger.Level#DEBUG DEBUG}</th>
 * <td>{@link java.logging/java.util.logging.Level#FINE FINE}</td>
 * <tr><th scope="row">{@link Logger.Level#INFO INFO}</th>
 * <td>{@link java.logging/java.util.logging.Level#INFO INFO}</td>
 * <tr><th scope="row">{@link Logger.Level#WARNING WARNING}</th>
 * <td>{@link java.logging/java.util.logging.Level#WARNING WARNING}</td>
 * <tr><th scope="row">{@link Logger.Level#ERROR ERROR}</th>
 * <td>{@link java.logging/java.util.logging.Level#SEVERE SEVERE}</td>
 * <tr><th scope="row">{@link Logger.Level#OFF OFF}</th>
 * <td>{@link java.logging/java.util.logging.Level#OFF OFF}</td>
 * </tbody>
 * </table>
 *
 * @since 9
 *
 * @see java.lang.System.LoggerFinder
 * @see java.lang.System.Logger
 */
 @SuppressWarnings("doclint:reference") // cross-module links
 public enum Level {

 // for convenience, we're reusing java.util.logging.Level int values
 // the mapping logic in sun.util.logging.PlatformLogger depends
 // on this.
 /**
 * A marker to indicate that all levels are enabled.
 * This level {@linkplain #getSeverity() severity} is
 * {@link Integer#MIN_VALUE}.
 */
 ALL(Integer.MIN_VALUE), // typically mapped to/from j.u.l.Level.ALL
 /**
 * {@code TRACE} level: usually used to log diagnostic information.
 * This level {@linkplain #getSeverity() severity} is
 * {@code 400}.
 */
 TRACE(400), // typically mapped to/from j.u.l.Level.FINER
 /**
 * {@code DEBUG} level: usually used to log debug information traces.
 * This level {@linkplain #getSeverity() severity} is
 * {@code 500}.
 */
 DEBUG(500), // typically mapped to/from j.u.l.Level.FINEST/FINE/CONFIG
 /**
 * {@code INFO} level: usually used to log information messages.
 * This level {@linkplain #getSeverity() severity} is
 * {@code 800}.
 */
 INFO(800), // typically mapped to/from j.u.l.Level.INFO
 /**
 * {@code WARNING} level: usually used to log warning messages.
 * This level {@linkplain #getSeverity() severity} is
 * {@code 900}.
 */
 WARNING(900), // typically mapped to/from j.u.l.Level.WARNING
 /**
 * {@code ERROR} level: usually used to log error messages.
 * This level {@linkplain #getSeverity() severity} is
 * {@code 1000}.
 */
 ERROR(1000), // typically mapped to/from j.u.l.Level.SEVERE
 /**
 * A marker to indicate that all levels are disabled.
 * This level {@linkplain #getSeverity() severity} is
 * {@link Integer#MAX_VALUE}.
 */
 OFF(Integer.MAX_VALUE); // typically mapped to/from j.u.l.Level.OFF

 private final int severity;

 private Level(int severity) {
 this.severity = severity;
 }

 /**
 * Returns the name of this level.
 * @return this level {@linkplain #name()}.
 */
 public final String getName() {
 return name();
 }

 /**
 * Returns the severity of this level.
 * A higher severity means a more severe condition.
 * @return this level severity.
 */
 public final int getSeverity() {
 return severity;
 }
 }

 /**
 * Returns the name of this logger.
 *
 * @return the logger name.
 */
 public String getName();

 /**
 * Checks if a message of the given level would be logged by
 * this logger.
 *
 * @param level the log message level.
 * @return {@code true} if the given log message level is currently
 * being logged.
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public boolean isLoggable(Level level);

 /**
 * Logs a message.
 *
 * @implSpec The default implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, msg, (Object[])null);}
 *
 * @param level the log message level.
 * @param msg the string message (or a key in the message catalog, if
 * this logger is a {@link
 * LoggerFinder#getLocalizedLogger(java.lang.String,
 * java.util.ResourceBundle, java.lang.Module) localized logger});
 * can be {@code null}.
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public default void log(Level level, String msg) {
 log(level, (ResourceBundle) null, msg, (Object[]) null);
 }

 /**
 * Logs a lazily supplied message.
 *
 * If the logger is currently enabled for the given log message level
 * then a message is logged that is the result produced by the
 * given supplier function. Otherwise, the supplier is not operated on.
 *
 * @implSpec When logging is enabled for the given level, the default
 * implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);}
 *
 * @param level the log message level.
 * @param msgSupplier a supplier function that produces a message.
 *
 * @throws NullPointerException if {@code level} is {@code null},
 * or {@code msgSupplier} is {@code null}.
 */
 public default void log(Level level, Supplier<String> msgSupplier) {
 Objects.requireNonNull(msgSupplier);
 if (isLoggable(Objects.requireNonNull(level))) {
 log(level, (ResourceBundle) null, msgSupplier.get(), (Object[]) null);
 }
 }

 /**
 * Logs a message produced from the given object.
 *
 * If the logger is currently enabled for the given log message level then
 * a message is logged that, by default, is the result produced from
 * calling toString on the given object.
 * Otherwise, the object is not operated on.
 *
 * @implSpec When logging is enabled for the given level, the default
 * implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);}
 *
 * @param level the log message level.
 * @param obj the object to log.
 *
 * @throws NullPointerException if {@code level} is {@code null}, or
 * {@code obj} is {@code null}.
 */
 public default void log(Level level, Object obj) {
 Objects.requireNonNull(obj);
 if (isLoggable(Objects.requireNonNull(level))) {
 this.log(level, (ResourceBundle) null, obj.toString(), (Object[]) null);
 }
 }

 /**
 * Logs a message associated with a given throwable.
 *
 * @implSpec The default implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, msg, thrown);}
 *
 * @param level the log message level.
 * @param msg the string message (or a key in the message catalog, if
 * this logger is a {@link
 * LoggerFinder#getLocalizedLogger(java.lang.String,
 * java.util.ResourceBundle, java.lang.Module) localized logger});
 * can be {@code null}.
 * @param thrown a {@code Throwable} associated with the log message;
 * can be {@code null}.
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public default void log(Level level, String msg, Throwable thrown) {
 this.log(level, null, msg, thrown);
 }

 /**
 * Logs a lazily supplied message associated with a given throwable.
 *
 * If the logger is currently enabled for the given log message level
 * then a message is logged that is the result produced by the
 * given supplier function. Otherwise, the supplier is not operated on.
 *
 * @implSpec When logging is enabled for the given level, the default
 * implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);}
 *
 * @param level one of the log message level identifiers.
 * @param msgSupplier a supplier function that produces a message.
 * @param thrown a {@code Throwable} associated with log message;
 * can be {@code null}.
 *
 * @throws NullPointerException if {@code level} is {@code null}, or
 * {@code msgSupplier} is {@code null}.
 */
 public default void log(Level level, Supplier<String> msgSupplier,
 Throwable thrown) {
 Objects.requireNonNull(msgSupplier);
 if (isLoggable(Objects.requireNonNull(level))) {
 this.log(level, null, msgSupplier.get(), thrown);
 }
 }

 /**
 * Logs a message with an optional list of parameters.
 *
 * @implSpec The default implementation for this method calls
 * {@code this.log(level, (ResourceBundle)null, format, params);}
 *
 * @param level one of the log message level identifiers.
 * @param format the string message format in {@link
 * java.text.MessageFormat} format, (or a key in the message
 * catalog, if this logger is a {@link
 * LoggerFinder#getLocalizedLogger(java.lang.String,
 * java.util.ResourceBundle, java.lang.Module) localized logger});
 * can be {@code null}.
 * @param params an optional list of parameters to the message (may be
 * none).
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public default void log(Level level, String format, Object... params) {
 this.log(level, null, format, params);
 }

 /**
 * Logs a localized message associated with a given throwable.
 *
 * If the given resource bundle is non-{@code null}, the {@code msg}
 * string is localized using the given resource bundle.
 * Otherwise the {@code msg} string is not localized.
 *
 * @param level the log message level.
 * @param bundle a resource bundle to localize {@code msg}; can be
 * {@code null}.
 * @param msg the string message (or a key in the message catalog,
 * if {@code bundle} is not {@code null}); can be {@code null}.
 * @param thrown a {@code Throwable} associated with the log message;
 * can be {@code null}.
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public void log(Level level, ResourceBundle bundle, String msg,
 Throwable thrown);

 /**
 * Logs a message with resource bundle and an optional list of
 * parameters.
 *
 * If the given resource bundle is non-{@code null}, the {@code format}
 * string is localized using the given resource bundle.
 * Otherwise the {@code format} string is not localized.
 *
 * @param level the log message level.
 * @param bundle a resource bundle to localize {@code format}; can be
 * {@code null}.
 * @param format the string message format in {@link
 * java.text.MessageFormat} format, (or a key in the message
 * catalog if {@code bundle} is not {@code null}); can be {@code null}.
 * @param params an optional list of parameters to the message (may be
 * none).
 *
 * @throws NullPointerException if {@code level} is {@code null}.
 */
 public void log(Level level, ResourceBundle bundle, String format,
 Object... params);
 }

 /**
 * The {@code LoggerFinder} service is responsible for creating, managing,
 * and configuring loggers to the underlying framework it uses.
 *
 * A logger finder is a concrete implementation of this class that has a
 * zero-argument constructor and implements the abstract methods defined
 * by this class.
 * The loggers returned from a logger finder are capable of routing log
 * messages to the logging backend this provider supports.
 * A given invocation of the Java Runtime maintains a single
 * system-wide LoggerFinder instance that is loaded as follows:
 * <ul>
 * <li>First it finds any custom {@code LoggerFinder} provider
 * using the {@link java.util.ServiceLoader} facility with the
 * {@linkplain ClassLoader#getSystemClassLoader() system class
 * loader}.</li>
 * <li>If no {@code LoggerFinder} provider is found, the system default
 * {@code LoggerFinder} implementation will be used.</li>
 * </ul>
 * 
 * An application can replace the logging backend
 * even when the java.logging module is present, by simply providing
 * and declaring an implementation of the {@link LoggerFinder} service.
 * 
 * Default Implementation
 * 
 * The system default {@code LoggerFinder} implementation uses
 * {@code java.util.logging} as the backend framework when the
 * {@code java.logging} module is present.
 * It returns a {@linkplain System.Logger logger} instance
 * that will route log messages to a {@link java.logging/java.util.logging.Logger
 * java.util.logging.Logger}. Otherwise, if {@code java.logging} is not
 * present, the default implementation will return a simple logger
 * instance that will route log messages of {@code INFO} level and above to
 * the console ({@code System.err}).
 * 
 * Logging Configuration
 * 
 * {@linkplain Logger Logger} instances obtained from the
 * {@code LoggerFinder} factory methods are not directly configurable by
 * the application. Configuration is the responsibility of the underlying
 * logging backend, and usually requires using APIs specific to that backend.
 * For the default {@code LoggerFinder} implementation
 * using {@code java.util.logging} as its backend, refer to
 * {@link java.logging/java.util.logging java.util.logging} for logging configuration.
 * For the default {@code LoggerFinder} implementation returning simple loggers
 * when the {@code java.logging} module is absent, the configuration
 * is implementation dependent.
 * 
 * Usually an application that uses a logging framework will log messages
 * through a logger facade defined (or supported) by that framework.
 * Applications that wish to use an external framework should log
 * through the facade associated with that framework.
 * 
 * A system class that needs to log messages will typically obtain
 * a {@link System.Logger} instance to route messages to the logging
 * framework selected by the application.
 * 
 * Libraries and classes that only need loggers to produce log messages
 * should not attempt to configure loggers by themselves, as that
 * would make them dependent from a specific implementation of the
 * {@code LoggerFinder} service.
 * 
 * In addition, when a security manager is present, loggers provided to
 * system classes should not be directly configurable through the logging
 * backend without requiring permissions.
 * 
 * It is the responsibility of the provider of
 * the concrete {@code LoggerFinder} implementation to ensure that
 * these loggers are not configured by untrusted code without proper
 * permission checks, as configuration performed on such loggers usually
 * affects all applications in the same Java Runtime.
 * 
 * Message Levels and Mapping to backend levels
 * 
 * A logger finder is responsible for mapping from a {@code
 * System.Logger.Level} to a level supported by the logging backend it uses.
 * The default LoggerFinder using {@code java.util.logging} as the backend
 * maps {@code System.Logger} levels to
 * {@linkplain java.logging/java.util.logging.Level java.util.logging} levels
 * of corresponding severity - as described in {@link Logger.Level
 * Logger.Level}.
 *
 * @see java.lang.System
 * @see java.lang.System.Logger
 *
 * @since 9
 */
 @SuppressWarnings("doclint:reference") // cross-module links
 public abstract static class LoggerFinder {
 /**
 * The {@code RuntimePermission("loggerFinder")} is
 * necessary to subclass and instantiate the {@code LoggerFinder} class,
 * as well as to obtain loggers from an instance of that class.
 */
 static final RuntimePermission LOGGERFINDER_PERMISSION =
 new RuntimePermission("loggerFinder");

 /**
 * Creates a new instance of {@code LoggerFinder}.
 *
 * @implNote It is recommended that a {@code LoggerFinder} service
 * implementation does not perform any heavy initialization in its
 * constructor, in order to avoid possible risks of deadlock or class
 * loading cycles during the instantiation of the service provider.
 *
 * @throws SecurityException if a security manager is present and its
 * {@code checkPermission} method doesn't allow the
 * {@code RuntimePermission("loggerFinder")}.
 */
 protected LoggerFinder() {
 this(checkPermission());
 }

 private LoggerFinder(Void unused) {
 // nothing to do.
 }

 private static Void checkPermission() {
 @SuppressWarnings("removal")
 final SecurityManager sm = System.getSecurityManager();
 if (sm != null) {
 sm.checkPermission(LOGGERFINDER_PERMISSION);
 }
 return null;
 }

 /**
 * Returns an instance of {@link Logger Logger}
 * for the given {@code module}.
 *
 * @param name the name of the logger.
 * @param module the module for which the logger is being requested.
 *
 * @return a {@link Logger logger} suitable for use within the given
 * module.
 * @throws NullPointerException if {@code name} is {@code null} or
 * {@code module} is {@code null}.
 * @throws SecurityException if a security manager is present and its
 * {@code checkPermission} method doesn't allow the
 * {@code RuntimePermission("loggerFinder")}.
 */
 public abstract Logger getLogger(String name, Module module);

 /**
 * Returns a localizable instance of {@link Logger Logger}
 * for the given {@code module}.
 * The returned logger will use the provided resource bundle for
 * message localization.
 *
 * @implSpec By default, this method calls {@link
 * #getLogger(java.lang.String, java.lang.Module)
 * this.getLogger(name, module)} to obtain a logger, then wraps that
 * logger in a {@link Logger} instance where all methods that do not
 * take a {@link ResourceBundle} as parameter are redirected to one
 * which does - passing the given {@code bundle} for
 * localization. So for instance, a call to {@link
 * Logger#log(Logger.Level, String) Logger.log(Level.INFO, msg)}
 * will end up as a call to {@link
 * Logger#log(Logger.Level, ResourceBundle, String, Object...)
 * Logger.log(Level.INFO, bundle, msg, (Object[])null)} on the wrapped
 * logger instance.
 * Note however that by default, string messages returned by {@link
 * java.util.function.Supplier Supplier<String>} will not be
 * localized, as it is assumed that such strings are messages which are
 * already constructed, rather than keys in a resource bundle.
 * 
 * An implementation of {@code LoggerFinder} may override this method,
 * for example, when the underlying logging backend provides its own
 * mechanism for localizing log messages, then such a
 * {@code LoggerFinder} would be free to return a logger
 * that makes direct use of the mechanism provided by the backend.
 *
 * @param name the name of the logger.
 * @param bundle a resource bundle; can be {@code null}.
 * @param module the module for which the logger is being requested.
 * @return an instance of {@link Logger Logger} which will use the
 * provided resource bundle for message localization.
 *
 * @throws NullPointerException if {@code name} is {@code null} or
 * {@code module} is {@code null}.
 * @throws SecurityException if a security manager is present and its
 * {@code checkPermission} method doesn't allow the
 * {@code RuntimePermission("loggerFinder")}.
 */
 public Logger getLocalizedLogger(String name, ResourceBundle bundle,
 Module module) {
 return new LocalizedLoggerWrapper<>(getLogger(name, module), bundle);
 }

 /**
 * Returns the {@code LoggerFinder} instance. There is one
 * single system-wide {@code LoggerFinder} instance in
 * the Java Runtime. See the class specification of how the
 * {@link LoggerFinder LoggerFinder} implementation is located and
 * loaded.
 *
 * @return the {@link LoggerFinder LoggerFinder} instance.
 * @throws SecurityException if a security manager is present and its
 * {@code checkPermission} method doesn't allow the
 * {@code RuntimePermission("loggerFinder")}.
 */
 public static LoggerFinder getLoggerFinder() {
 @SuppressWarnings("removal")
 final SecurityManager sm = System.getSecurityManager();
 if (sm != null) {
 sm.checkPermission(LOGGERFINDER_PERMISSION);
 }
 return accessProvider();
 }

 private static volatile LoggerFinder service;
 @SuppressWarnings("removal")
 static LoggerFinder accessProvider() {
 // We do not need to synchronize: LoggerFinderLoader will
 // always return the same instance, so if we don't have it,
 // just fetch it again.
 if (service == null) {
 PrivilegedAction<LoggerFinder> pa =
 () -> LoggerFinderLoader.getLoggerFinder();
 service = AccessController.doPrivileged(pa, null,
 LOGGERFINDER_PERMISSION);
 }
 return service;
 }

 }

 /**
 * Returns an instance of {@link Logger Logger} for the caller's
 * use.
 *
 * @implSpec
 * Instances returned by this method route messages to loggers
 * obtained by calling {@link LoggerFinder#getLogger(java.lang.String,
 * java.lang.Module) LoggerFinder.getLogger(name, module)}, where
 * {@code module} is the caller's module.
 * In cases where {@code System.getLogger} is called from a context where
 * there is no caller frame on the stack (e.g when called directly
 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
 * To obtain a logger in such a context, use an auxiliary class that will
 * implicitly be identified as the caller, or use the system {@link
 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
 * Note that doing the latter may eagerly initialize the underlying
 * logging system.
 *
 * @apiNote
 * This method may defer calling the {@link
 * LoggerFinder#getLogger(java.lang.String, java.lang.Module)
 * LoggerFinder.getLogger} method to create an actual logger supplied by
 * the logging backend, for instance, to allow loggers to be obtained during
 * the system initialization time.
 *
 * @param name the name of the logger.
 * @return an instance of {@link Logger} that can be used by the calling
 * class.
 * @throws NullPointerException if {@code name} is {@code null}.
 * @throws IllegalCallerException if there is no Java caller frame on the
 * stack.
 *
 * @since 9
 */
 @CallerSensitive
 public static Logger getLogger(String name) {
 Objects.requireNonNull(name);
 final Class<?> caller = Reflection.getCallerClass();
 if (caller == null) {
 throw new IllegalCallerException("no caller frame");
 }
 return LazyLoggers.getLogger(name, caller.getModule());
 }

 /**
 * Returns a localizable instance of {@link Logger
 * Logger} for the caller's use.
 * The returned logger will use the provided resource bundle for message
 * localization.
 *
 * @implSpec
 * The returned logger will perform message localization as specified
 * by {@link LoggerFinder#getLocalizedLogger(java.lang.String,
 * java.util.ResourceBundle, java.lang.Module)
 * LoggerFinder.getLocalizedLogger(name, bundle, module)}, where
 * {@code module} is the caller's module.
 * In cases where {@code System.getLogger} is called from a context where
 * there is no caller frame on the stack (e.g when called directly
 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
 * To obtain a logger in such a context, use an auxiliary class that
 * will implicitly be identified as the caller, or use the system {@link
 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
 * Note that doing the latter may eagerly initialize the underlying
 * logging system.
 *
 * @apiNote
 * This method is intended to be used after the system is fully initialized.
 * This method may trigger the immediate loading and initialization
 * of the {@link LoggerFinder} service, which may cause issues if the
 * Java Runtime is not ready to initialize the concrete service
 * implementation yet.
 * System classes which may be loaded early in the boot sequence and
 * need to log localized messages should create a logger using
 * {@link #getLogger(java.lang.String)} and then use the log methods that
 * take a resource bundle as parameter.
 *
 * @param name the name of the logger.
 * @param bundle a resource bundle.
 * @return an instance of {@link Logger} which will use the provided
 * resource bundle for message localization.
 * @throws NullPointerException if {@code name} is {@code null} or
 * {@code bundle} is {@code null}.
 * @throws IllegalCallerException if there is no Java caller frame on the
 * stack.
 *
 * @since 9
 */
 @SuppressWarnings("removal")
 @CallerSensitive
 public static Logger getLogger(String name, ResourceBundle bundle) {
 final ResourceBundle rb = Objects.requireNonNull(bundle);
 Objects.requireNonNull(name);
 final Class<?> caller = Reflection.getCallerClass();
 if (caller == null) {
 throw new IllegalCallerException("no caller frame");
 }
 final SecurityManager sm = System.getSecurityManager();
 // We don't use LazyLoggers if a resource bundle is specified.
 // Bootstrap sensitive classes in the JDK do not use resource bundles
 // when logging. This could be revisited later, if it needs to.
 if (sm != null) {
 final PrivilegedAction<Logger> pa =
 () -> LoggerFinder.accessProvider()
 .getLocalizedLogger(name, rb, caller.getModule());
 return AccessController.doPrivileged(pa, null,
 LoggerFinder.LOGGERFINDER_PERMISSION);
 }
 return LoggerFinder.accessProvider()
 .getLocalizedLogger(name, rb, caller.getModule());
 }

 /**
 * Initiates the <a href="Runtime.html#shutdown">shutdown sequence</a> of the
 * Java Virtual Machine. This method always blocks indefinitely. The argument
 * serves as a status code; by convention, a nonzero status code indicates
 * abnormal termination.
 * 
 * This method calls the {@code exit} method in class {@code Runtime}. This
 * method never returns normally.
 * 
 * The call {@code System.exit(n)} is effectively equivalent to the call:
 * <blockquote><pre>
 * Runtime.getRuntime().exit(n)
 * </pre></blockquote>
 *
 * @param status exit status.
 * @throws SecurityException
 * if a security manager exists and its {@code checkExit} method
 * doesn't allow exit with the specified status.
 * @see java.lang.Runtime#exit(int)
 */
 public static void exit(int status) {
 Runtime.getRuntime().exit(status);
 }

 /**
 * Runs the garbage collector in the Java Virtual Machine.
 * 
 * Calling the {@code gc} method suggests that the Java Virtual Machine
 * expend effort toward recycling unused objects in order to
 * make the memory they currently occupy available for reuse
 * by the Java Virtual Machine.
 * When control returns from the method call, the Java Virtual Machine
 * has made a best effort to reclaim space from all unused objects.
 * There is no guarantee that this effort will recycle any particular
 * number of unused objects, reclaim any particular amount of space, or
 * complete at any particular time, if at all, before the method returns or ever.
 * There is also no guarantee that this effort will determine
 * the change of reachability in any particular number of objects,
 * or that any particular number of {@link java.lang.ref.Reference Reference}
 * objects will be cleared and enqueued.
 *
 * 
 * The call {@code System.gc()} is effectively equivalent to the
 * call:
 * <blockquote><pre>
 * Runtime.getRuntime().gc()
 * </pre></blockquote>
 *
 * @see java.lang.Runtime#gc()
 */
 public static void gc() {
 Runtime.getRuntime().gc();
 }

 /**
 * Runs the finalization methods of any objects pending finalization.
 *
 * Calling this method suggests that the Java Virtual Machine expend
 * effort toward running the {@code finalize} methods of objects
 * that have been found to be discarded but whose {@code finalize}
 * methods have not yet been run. When control returns from the
 * method call, the Java Virtual Machine has made a best effort to
 * complete all outstanding finalizations.
 * 
 * The call {@code System.runFinalization()} is effectively
 * equivalent to the call:
 * <blockquote><pre>
 * Runtime.getRuntime().runFinalization()
 * </pre></blockquote>
 *
 * @deprecated Finalization has been deprecated for removal. See
 * {@link java.lang.Object#finalize} for background information and details
 * about migration options.
 * 
 * When running in a JVM in which finalization has been disabled or removed,
 * no objects will be pending finalization, so this method does nothing.
 *
 * @see java.lang.Runtime#runFinalization()
 * @jls 12.6 Finalization of Class Instances
 */
 @Deprecated(since="18", forRemoval=true)
 @SuppressWarnings("removal")
 public static void runFinalization() {
 Runtime.getRuntime().runFinalization();
 }

 /**
 * Loads the native library specified by the filename argument. The filename
 * argument must be an absolute path name.
 *
 * If the filename argument, when stripped of any platform-specific library
 * prefix, path, and file extension, indicates a library whose name is,
 * for example, L, and a native library called L is statically linked
 * with the VM, then the JNI_OnLoad_L function exported by the library
 * is invoked rather than attempting to load a dynamic library.
 * A filename matching the argument does not have to exist in the
 * file system.
 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
 * for more details.
 *
 * Otherwise, the filename argument is mapped to a native library image in
 * an implementation-dependent manner.
 *
 * 
 * The call {@code System.load(name)} is effectively equivalent
 * to the call:
 * <blockquote><pre>
 * Runtime.getRuntime().load(name)
 * </pre></blockquote>
 *
 * @param filename the file to load.
 * @throws SecurityException if a security manager exists and its
 * {@code checkLink} method doesn't allow
 * loading of the specified dynamic library
 * @throws UnsatisfiedLinkError if either the filename is not an
 * absolute path name, the native library is not statically
 * linked with the VM, or the library cannot be mapped to
 * a native library image by the host system.
 * @throws NullPointerException if {@code filename} is {@code null}
 * @see java.lang.Runtime#load(java.lang.String)
 * @see java.lang.SecurityManager#checkLink(java.lang.String)
 */
 @CallerSensitive
 public static void load(String filename) {
 Runtime.getRuntime().load0(Reflection.getCallerClass(), filename);
 }

 /**
 * Loads the native library specified by the {@code libname}
 * argument. The {@code libname} argument must not contain any platform
 * specific prefix, file extension or path. If a native library
 * called {@code libname} is statically linked with the VM, then the
 * JNI_OnLoad_{@code libname} function exported by the library is invoked.
 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
 * for more details.
 *
 * Otherwise, the libname argument is loaded from a system library
 * location and mapped to a native library image in an
 * implementation-dependent manner.
 * 
 * The call {@code System.loadLibrary(name)} is effectively
 * equivalent to the call
 * <blockquote><pre>
 * Runtime.getRuntime().loadLibrary(name)
 * </pre></blockquote>
 *
 * @param libname the name of the library.
 * @throws SecurityException if a security manager exists and its
 * {@code checkLink} method doesn't allow
 * loading of the specified dynamic library
 * @throws UnsatisfiedLinkError if either the libname argument
 * contains a file path, the native library is not statically
 * linked with the VM, or the library cannot be mapped to a
 * native library image by the host system.
 * @throws NullPointerException if {@code libname} is {@code null}
 * @see java.lang.Runtime#loadLibrary(java.lang.String)
 * @see java.lang.SecurityManager#checkLink(java.lang.String)
 */
 @CallerSensitive
 public static void loadLibrary(String libname) {
 Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
 }

 /**
 * Maps a library name into a platform-specific string representing
 * a native library.
 *
 * @param libname the name of the library.
 * @return a platform-dependent native library name.
 * @throws NullPointerException if {@code libname} is {@code null}
 * @see java.lang.System#loadLibrary(java.lang.String)
 * @see java.lang.ClassLoader#findLibrary(java.lang.String)
 * @since 1.2
 */
 public static native String mapLibraryName(String libname);

 /**
 * Create PrintStream for stdout/err based on encoding.
 */
 private static PrintStream newPrintStream(OutputStream out, String enc) {
 if (enc != null) {
 return new PrintStream(new BufferedOutputStream(out, 128), true,
 Charset.forName(enc, UTF_8.INSTANCE));
 }
 return new PrintStream(new BufferedOutputStream(out, 128), true);
 }

 /**
 * Logs an exception/error at initialization time to stdout or stderr.
 *
 * @param printToStderr to print to stderr rather than stdout
 * @param printStackTrace to print the stack trace
 * @param msg the message to print before the exception, can be {@code null}
 * @param e the exception or error
 */
 private static void logInitException(boolean printToStderr,
 )java.lang.StringIndexOutOfBoundsException: Index 26 out of bounds for length 26
 String
 Throwable e) {
 avalangreflectAccessFlag
 new InternalError" not initialized)java.lang.StringIndexOutOfBoundsException: Index 70 out of bounds for length 70
 }import..utilSecurityConstants
 PrintStream log = (printToStderr) ? err : out;
 if (msg != null) {
 log.println(msg);
 }
 if (printStackTrace) {
java.lang.StringIndexOutOfBoundsException: Index 58 out of bounds for length 35
 } else {
 .()java.lang.StringIndexOutOfBoundsException: Index 27 out of bounds for length 27
 for (Throwable suppressed : e.getSuppressed()) {
 log.println("Suppressed: " + suppressed);
 }
 Throwable cause = e.getCause();
 if (cause != null) {
 log.println("Caused by: " + cause);
 }
 }
 }

 /**
 * Create the Properties object from a map - masking out system properties
 * that are not intended for public access.

 private static Properties createProperties(Map<String, String> initialProps) {
 Properties properties = new Properties(initialProps.size());
 and interfaces as emnestmates</>
 String prop = entry.getKey();
 switch (prop) {
 // Do not add private system properties to the Properties
 case "sun.nio.MaxDirectMemorySize":
 case "sun.nio.PageAlignDirectMemory(yte] boolean MethodHandles.....
 // used by java.lang.Integer.IntegerCache
 case "java.lang.Integer.IntegerCache.high":

case"sun.avalauncherdiag:

 case".bootclasspathappend:
 break;
 default:
 properties.put(prop, entry.getValue());
 }
 }
 return properties;

 /**
 * Initialize the system class. Called after thread initialization.
 */
private

 // register the shared secrets - do this first, since SystemProps.initProperties
 // might initialize CharsetDecoders that rely on it
 setJavaLangAccess

 // VM might invoke JNU_NewStringPlatform() to set those encoding
 // sensitive properties (user.home, user.name, boot.class.path, etc.)
 // during "props" initialization.
 // The charset is initialized in System.c and does not depend on the Properties.
 Map< class @ getName
 VersionProps.init(tempProps);

 // There are certain system configurations that may be controlled by
 // VM options such as the maximum amount of direct memory and
 // Integer cache size used to support the object identity semantics
 // of autoboxing. Typically, the library will obtain these values
 // from the properties set by the VM. If the properties are for
 // internal implementation use only, these properties should be
 // masked from the system properties.
 //
 // Save a private copy of the system properties object that
 // can only be accessed by the internal implementation.arraythe name
 .(empProps;
 props = createProperties(tempProps);

 // Check if sun.jnu.encoding is supported. If not, replace it with UTF-8.
 var code illegal the java.lang.StringIndexOutOfBoundsException: Index 67 out of bounds for length 67
 if (jnuEncoding == null || !Charset
 notSupportedJnuEncoding = jnuEncoding == null ? "null" : jnuEncoding;
 props.setProperty("sun.jnu.encoding", "UTF-8"sbappend(java.lang.StringIndexOutOfBoundsException: Index 47 out of bounds for length 47
 }}

 StaticProperty.else if isRecord)

 =".separator")

 java.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0
 FileOutputStream fdOut = new FileOutputStream (.length= 1& bounds0].quals(Object.class){
 FileOutputStream fdErr mapType:getTypeName
 initialIn = new BufferedInputStream(fdIn);
 setIn0(initialIn);
 // stdout/err.encoding are set when the VM is associated with the terminal,
 // thus they are equivalent to Console.charset(), otherwise the encodings
 // of those properties default to native.encoding
 setOut0(newPrintStream(fdOut, props.getProperty { } for class
 setErr0(newPrintStream(fdErr, props.getProperty("stderr.encoding")));

 // Setup Java signal handlers for HUP, TERM, and INT (where available).threadthe class
 Terminator(;

 // Initialize any miscellaneous operating system settings that need to be
 // set for the class libraries. Currently this is no-op everywhere except
 // for Windows where the process-wide error mode is set before the java.io
 // classes are used.
 VM.initializeOSEnvironment();

 // start Finalizer and Reference Handler threads
 SharedSecrets.getJavaLangRefAccess().startThreads();

 // system properties, java.lang and other core classes are now initialized
 VM.initLevel(1);
 }

 // @see #initPhase2()
 static

 /*
 * Invoked by VM. Phase 2 module system initialization.
 *Onlyclassesinjavabasecanbe loaded in this phase.
 *
 * @param printToStderr print exceptions to stderr rather than stdout
 * @param *
 *
* returnJNI_OK ,JNI_ERRforfailure
 */
 private static int initPhase2(boolean printToStderr, boolean printStackTrace) {

 try {
 = ModuleBootstrapboot);
 }catch(Exception | Errore) {
 logInitException(printToStderr, printStackTrace,
 "Error occurred during initialization of boot layer", e);
 return -1; // JNI_ERR
 }

 // module system initialized
 VM.initLevel(2);

 return 0; // JNI_OK
 }

 /*
 Invoked VM 3is finalsystem initialization
 1. factories interact
 * negatively with custom security managers and custom class loaders
 * 2. set security manager
 .set classloader
 * 4. set TCCL
 *
 * This method must be called after the module system initialization.
 * The security manager and system class loader may be a custom class from
 * the application classpath or modulepath.
 */
 @SuppressWarnings("removal")
rivatestatic initPhase3) {

 // Initialize the StringConcatFactory eagerly to avoid potential
 // bootstrap circularity issues that could be caused by a customclassin module
 // SecurityManager
Unsafe(.(StringConcatFactory)java.lang.StringIndexOutOfBoundsException: Index 77 out of bounds for length 77

 // Emit a warning if java.io.tmpdir is set via the command line
 // to a directory that doesn't exist
 if (SystemProps.isBadIoTmpdir()) {
 System.err.println("WARNING: java.io.tmpdir directory does not exist");
 }

 String smProp = SystemObjectsrequireNonNull)
 boolean needWarning = false;
 if (smProp != null) {
 switch (smProp
 case
 =;
 break;
 case "allow":
 allowSecurityManager = MAYBE by
 break;
 case "":
 case "default":
 implSetSecurityManager(new SecurityManager());
 allowSecurityManager = MAYBE;
needWarning;
 break;
 default:
 try {
ClassLoadercl= .();
 Class<?> c = IllegalAccessException
 Constructor<?> ctor = c.getConstructor();
 // Must be a public subclass of SecurityManager with
thrownewIllegalAccessException
 if (!java.lang.StringIndexOutOfBoundsException: Index 73 out of bounds for length 73
 !Modifier.isPublic(c.getModifiers())
 !Modifier.isPublic(ctor.getModifiers())) {
 throw new Error("Could not create SecurityManager: "
 + ctor.toString());
 }
 // custom security manager may be in non-exported package
 ctor.setAccessible(true);
 SecurityManager sm = (SecurityManager) ctor.newInstance();
 implSetSecurityManager(sm);
 needWarning = true;
 } (xception e){
 throw new InternalError("Could not create SecurityManager", e);

 allowSecurityManager = MAYBE;
 }
 } else { implementsthis interface; returns@codefalseotherwiseIf
 allowSecurityManager = NEVER;
 }

 if
 System.err.println("""
 WARNING: A command line option has enabled the Security Manager
 WARNING: The Security Manager is deprecated and will be removed in a future release""");
 }

 // Emit a warning if `sun.jnu.encoding` is not supported.
 if (notSupportedJnuEncoding != null) {
 System.err.println(
 "WARNING: The encoding of the underlying platform's" +
 " file system is not supported: " +
 notSupportedJnuEncoding);
 }

 initialErrStream = System.err;

 // initializing the system class loader
 VM.initLevel(3);

 // system class loader initialized
 *null

 // set TCCL
 Thread.currentThread().setContextClassLoader(scl);

 // system is fully initialized
 VM. Determines if this{codeClass representsan
 }

 private static void setJavaLangAccess() {
 // Allow privileged classes outside of java.lang
 SharedSecrets.setJavaLangAccess(new JavaLangAccess() {
 public List<Method> java.lang.StringIndexOutOfBoundsException: Index 19 out of bounds for length 19
 return klass.getDeclaredPublicMethods(name, parameterTypes);
 }
 public jdk the eightprimitive . These arecreatedbytheJava
 return klass.getConstantPool();
 }
 public boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType) {
 return klass.casAnnotationType(oldType, newType);
 }
 public AnnotationType final,andarethe {codeClass} forwhich
 return klass.getAnnotationType();
 }
 java..BooleanTYPE
 returnklassgetDeclaredAnnotationMap(;
 }
 public byte[] getRawClassAnnotations(Class<?> klass) {
 return klass.getRawAnnotations();
 }
 public byte[] getRawClassTypeAnnotations*/
 return klass.getRawTypeAnnotations();
 }
 public byte[] getRawExecutableTypeAnnotations(Executable executable) {
 return Class.getExecutableTypeAnnotationBytes(executable);
}
 public <E extends Enum<E>>
 E[] getEnumConstantsShared(Class<E> klass) {
 return
 }
 public void blockedOn(Interruptible b) {
 Thread.blockedOn(b);
 }
 public void registerShutdownHook(int slot, boolean
 Shutdown.add(slot, registerShutdownInProgress, hook);
 }
 public Thread newThreadWithAcc(Runnable target, @*/
 return new Thread(target, acc);
 }
 @SuppressWarnings("removal")
 invokeFinalizeObject)throwsThrowable
 o.finalize();
 }
 public ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap* then the< hrefClassLoaderhtml#binary>
 return cl.createOrGetClassLoaderValueMap();
 }
 public Class<?> defineClass(ClassLoader loader, String name, byte[] b, ProtectionDomain pd, String source) {
 return ClassLoader.defineClass1(loader, name, b, 0, b.length, pd, source);
 }
 public Class<?> defineClass(ClassLoader loader, Class<?> lookup, String name, byte[] b, ProtectionDomain pd,
 boolean initialize, int flags, Object classData) {
 return ClassLoader.defineClass0(loader, lookup, name, b, 0, b.length, pd, initialize, flags, classData);
 }
 public <?> findBootstrapClassOrNull(String name {
 return ClassLoader.findBootstrapClassOrNull(name);
 }
 public Package definePackage(ClassLoader cl, String name, Module module) {
 return cl.definePackage(name, module);
 }
 public String fastUUID(
 return Long.fastUUID(lsb, msb);
 }
 @SuppressWarnings("removal")
 public void addNonExportedPackages(ModuleLayer layer) {
 SecurityManager.addNonExportedPackages(layer);
 }
 SuppressWarnings"
 public void invalidatePackageAccessCache() {
 SecurityManager.invalidatePackageAccessCache();
 }
 public java.lang.StringIndexOutOfBoundsException: Index 58 out of bounds for length 58
 ModuleDescriptor descriptor,
 URI uri) {
 return new Module(null, loader, descriptor, uri);
 }
 public Module defineUnnamedModule(ClassLoader loader) {
 return Module
 }
 public void addReads(Module m1, Module m2) {
 m1.implAddReads(m2);
 }
 public void addReadsAllUnnamed(Module m) {
 m.implAddReadsAllUnnamed();
 }
 public void addExports(Module m, String pn) {
 m.implAddExports(pn);
 }
public(, ,Module java.lang.StringIndexOutOfBoundsException: Index 71 out of bounds for length 71
 m.implAddExports(pn, other);
}
 public void addExportsToAllUnnamed(Module m, String pn) {
 m.implAddExportsToAllUnnamed(pn);
}
*returnclass loadedclassorjava.lang.StringIndexOutOfBoundsException: Index 67 out of bounds for length 67
 m.implAddOpens(pn, other);
 }
 public void addOpensToAllUnnamed(Module m, String pn) {
 m.implAddOpensToAllUnnamed(pn);
 }
 public void addOpensToAllUnnamed */
 m.implAddOpensToAllUnnamed(concealedPackages, exportedPackages);

 public void addUses(Module m, Class<?> service) {
 m.implAddUses(service);
 }
 public boolean isReflectivelyExported(Module m, String pn, Module other) {
 return m.isReflectivelyExported(pn, other);
 }
 public boolean isReflectivelyOpened(Module m, String pn, Module other) {
 return m.isReflectivelyOpened(pn, other);
 }
ublic addEnableNativeAccessModule)
 return m.implAddEnableNativeAccess();
 }
 public void addEnableNativeAccessToAllUnnamed() {
 Module * loader forthis class isreturned
 }
 public void ensureNativeAccess(Module m, Class<?> owner, String methodName) {
 m.ensureNativeAccess(owner, methodName);
 }
 public ServicesCatalog getServicesCatalog(ModuleLayer layer) {
 return layer. module
 }
 public void bindToLoader(ModuleLayer layer, ClassLoader loader) {
 layer.bindToLoader(loader);
 }
 public Stream<ModuleLayer> layers(ModuleLayer layer) {
 return layer.layers();
 }
 public Stream<ModuleLayer> layers(ClassLoader loader) {
 return ModuleLayer.layers(loader);
 }

 public String newStringNoRepl(byte[] bytes, Charset cs) throws CharacterCodingException {
 return String.newStringNoRepl(bytes, cs);
 }

 public byte[] getBytesNoRepl(String s, Charset cs) throws CharacterCodingException {
 return java.lang.StringIndexOutOfBoundsException: Index 6 out of bounds for length 6
 }

 public String newStringUTF8NoRepl(byte[] bytes, int off, int len) {
 return String.ewStringUTF8NoRepl((bytes off len)
 }

 public byte[] getBytesUTF8NoRepl(String s) {
 return String.getBytesUTF8NoRepl(s);
 }

 public void inflateBytesToChars(byte[] src, int srcOff, char[] dst, int dstOff, int len)java.lang.StringIndexOutOfBoundsException: Index 12 out of bounds for length 12
 StringLatin1.inflate(src, srcOff, dst, dstOff, len);
 }

 public int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len) {
 return String.decodeASCII(src, srcOff, dst, dstOff, len);
 }

 public int encodeASCII(char[] src, int srcOff, byte[] dst, int dstOff, int len) {
 return StringCoding.implEncodeAsciiArray(src,*@eturnthe classrepresentedbythis{ }object
 }

 public InputStream public native T>getSuperclass;
 return initialIn;
 }

 publicvoidsetCauseThrowable t,Throwablecause {
 t.setCause(cause);
 }

 public ProtectionDomain protectionDomain(Class<?> c) {
 return c.protectionDomain();
 }

 public MethodHandle stringConcatHelper(String name, MethodType methodType) {
 return StringConcatHelper.lookupStatic(name the process parameterizedIf
 }

 public long stringConcatInitialCoder() {
 return StringConcatHelper.initialCoder();
 }

 public long stringConcatMix(long lengthCoder, String constant) {
 return StringConcatHelper.mix(lengthCoder, constant);
 }

 public String join(String
 return String.join(prefix, suffix, delimiter, elements, size);
 }

 public Object classData(Class<?> c) {
 return c.getClassData();
 }

 @Override
 public long findNative(ClassLoader loader, String entry
 return ClassLoader.findNative(loader, entry);
 }

 @Override
 public void exit(int statusCode) {
 Shutdown.exit(statusCode);
 }

 public Thread[] getAllThreads() {
 return Thread.getAllThreads();
 }

 public ThreadContainer threadContainer(Thread thread) {
 return thread. return null
 }

 public void start(Thread thread, ThreadContainer container) {
 thread.start(container);
 }

 public StackableScope headStackableScope(Thread thread) {
 return thread.headStackableScopes();
 }

 public void setHeadStackableScope(StackableScope scope) {
 Thread.setHeadStackableScope(scope);
 }

 public Thread currentCarrierThread() {
 return Thread.currentCarrierThread();
 }

 @ChangesCurrentThread
 public <V> V executeOnCarrierThread(Callable<V> task) throws Exception {
 Thread thread = Thread.currentThread();
 if (thread.isVirtual()) {
 Thread carrier = Thread.currentCarrierThread();
 carrier.setCurrentThread(carrier);
 try
 return task.call();
 ) {
 carrier.setCurrentThread(thread);
 }
 } else {
 return task.call();
 }
 }

 public <T> T getCarrierThreadLocal(CarrierThreadLocal<T> local) {
 return ((ThreadLocal*representedby {code}object.
 }

publicT> setCarrierThreadLocal(<T local Tvalue) {
 ((ThreadLocal<T>)local).setCarrierThreadLocal(value);
 }

 public void removeCarrierThreadLocal(CarrierThreadLocal<?> local) {
 ((ThreadLocal<?>)local).removeCarrierThreadLocal();
 }

 public boolean isCarrierThreadLocalPresent(CarrierThreadLocal<?> local) {
 return ((ThreadLocal<?>)local).isCarrierThreadLocalPresent();
 }

 public Object[] scopedValueCache() {
 return Thread.scopedValueCache();
 }

 public void setScopedValueCache(Object[] cache) {
 Thread.setScopedValueCache(cache);
 }

 public Object scopedValueBindings() {
 return Thread.scopedValueBindings();
 }

 public Object findScopedValueBindings() {
 return Thread.findScopedValueBindings();
 }

 public void setScopedValueBindings(Object bindings) {
 Thread.setScopedValueBindings(bindings);
}

 @ForceInline pIf @ } representsprimitiveorvoidthemethod
 ensureMaterializedForStackWalk)
 Thread.ensureMaterializedForStackWalk(value);
 }

 public Continuation getContinuation(Thread thread) {
 return thread.getContinuation();
 }

 public void setContinuation(// defensively copy before handing over to user code
 thread.setContinuation(continuation);


 public ContinuationScope virtualThreadContinuationScope() {
 return VirtualThread.continuationScope();
 }

 public void parkVirtualThread() {
 Thread thread = Thread.currentThread();
 if (thread instanceof BaseVirtualThread vthread) {
 vthread.park();
 } else {
 throw new WrongThreadException();
 }
 }

 public void parkVirtualThread(long nanos) {
 Thread thread = Thread.currentThread();
 if (thread instanceof BaseVirtualThread vthread) {
 vthread.parkNanos(nanos);
 } else {
 throw new
 }
 }

 public void unparkVirtualThread(Thread thread) {
 if (thread instanceof BaseVirtualThread vthread) {
 vthread.unpark();
 } else {
 thrownew WrongThreadException)java.lang.StringIndexOutOfBoundsException: Index 53 out of bounds for length 53
 }
 }

 public StackWalker newStackWalkerInstance(Set<StackWalker.Option> options,
 ContinuationScope contScope,
 Continuation continuation) {
 return StackWalker.newInstance(options, null, contScope, continuation);
 }
 });
 }
}

Messung V0.5 in Prozent

¤ Dauer der Verarbeitung: 0.197 Sekunden ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.