Quelle JspContextWrapper.java Sprache: JAVA

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jasper.runtime;

import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import jakarta.el.ELContext;
import jakarta.el.ELResolver;
import jakarta.el.EvaluationListener;
import jakarta.el.FunctionMapper;
import jakarta.el.ImportHandler;
import jakarta.el.VariableMapper;
import jakarta.servlet.Servlet;
import jakarta.servlet.ServletConfig;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpSession;
import jakarta.servlet.jsp.JspApplicationContext;
import jakarta.servlet.jsp.JspContext;
import jakarta.servlet.jsp.JspFactory;
import jakarta.servlet.jsp.JspWriter;
import jakarta.servlet.jsp.PageContext;
import jakarta.servlet.jsp.el.ELException;
import jakarta.servlet.jsp.el.ExpressionEvaluator;
import jakarta.servlet.jsp.el.NotFoundELResolver;
import jakarta.servlet.jsp.el.VariableResolver;
import jakarta.servlet.jsp.tagext.BodyContent;
import jakarta.servlet.jsp.tagext.JspTag;
import jakarta.servlet.jsp.tagext.VariableInfo;

import org.apache.jasper.compiler.Localizer;

/**
* Implementation of a JSP Context Wrapper.
*
* The JSP Context Wrapper is a JspContext created and maintained by a tag
* handler implementation. It wraps the Invoking JSP Context, that is, the
* JspContext instance passed to the tag handler by the invoking page via
* setJspContext().
*
* @author Kin-man Chung
* @author Jan Luehe
* @author Jacob Hookom
*/
@SuppressWarnings("deprecation") // Have to support old JSP EL API
public class JspContextWrapper extends PageContext implements VariableResolver {

    private final JspTag jspTag;

    // Invoking JSP context
    private final PageContext invokingJspCtxt;

    private final transient HashMap<String, Object> pageAttributes;

    // ArrayList of NESTED scripting variables
    private final ArrayList<String> nestedVars;

    // ArrayList of AT_BEGIN scripting variables
    private final ArrayList<String> atBeginVars;

    // ArrayList of AT_END scripting variables
    private final ArrayList<String> atEndVars;

    private final Map<String,String> aliases;

    private final HashMap<String, Object> originalNestedVars;

    private ServletContext servletContext = null;

    private ELContext elContext = null;

    private final PageContext rootJspCtxt;

    public JspContextWrapper(JspTag jspTag, JspContext jspContext,
            ArrayList<String> nestedVars, ArrayList<String> atBeginVars,
            ArrayList<String> atEndVars, Map<String,String> aliases) {
        this.jspTag = jspTag;
        this.invokingJspCtxt = (PageContext) jspContext;
        if (jspContext instanceof JspContextWrapper) {
            rootJspCtxt = ((JspContextWrapper)jspContext).rootJspCtxt;
        } else {
            rootJspCtxt = invokingJspCtxt;
        }
        this.nestedVars = nestedVars;
        this.atBeginVars = atBeginVars;
        this.atEndVars = atEndVars;
        this.pageAttributes = new HashMap<>(16);
        this.aliases = aliases;

        if (nestedVars != null) {
            this.originalNestedVars = new HashMap<>(nestedVars.size());
        } else {
            this.originalNestedVars = null;
        }
        syncBeginTagFile();
    }

    @Override
    public void initialize(Servlet servlet, ServletRequest request,
            ServletResponse response, String errorPageURL,
            boolean needsSession, int bufferSize, boolean autoFlush)
            throws IOException, IllegalStateException, IllegalArgumentException {
    }

    @Override
    public Object getAttribute(String name) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        return pageAttributes.get(name);
    }

    @Override
    public Object getAttribute(String name, int scope) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        if (scope == PAGE_SCOPE) {
            return pageAttributes.get(name);
        }

        return rootJspCtxt.getAttribute(name, scope);
    }

    @Override
    public void setAttribute(String name, Object value) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        if (value != null) {
            pageAttributes.put(name, value);
        } else {
            removeAttribute(name, PAGE_SCOPE);
        }
    }

    @Override
    public void setAttribute(String name, Object value, int scope) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        if (scope == PAGE_SCOPE) {
            if (value != null) {
                pageAttributes.put(name, value);
            } else {
                removeAttribute(name, PAGE_SCOPE);
            }
        } else {
            rootJspCtxt.setAttribute(name, value, scope);
        }
    }

    @Override
    public Object findAttribute(String name) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        Object o = pageAttributes.get(name);
        if (o == null) {
            o = rootJspCtxt.getAttribute(name, REQUEST_SCOPE);
            if (o == null) {
                if (getSession() != null) {
                    try {
                        o = rootJspCtxt.getAttribute(name, SESSION_SCOPE);
                    } catch (IllegalStateException ise) {
                        // Session has been invalidated.
                        // Ignore and fall through to application scope.
                    }
                }
                if (o == null) {
                    o = rootJspCtxt.getAttribute(name, APPLICATION_SCOPE);
                }
            }
        }

        return o;
    }

    @Override
    public void removeAttribute(String name) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        pageAttributes.remove(name);
        rootJspCtxt.removeAttribute(name, REQUEST_SCOPE);
        if (getSession() != null) {
            rootJspCtxt.removeAttribute(name, SESSION_SCOPE);
        }
        rootJspCtxt.removeAttribute(name, APPLICATION_SCOPE);
    }

    @Override
    public void removeAttribute(String name, int scope) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        if (scope == PAGE_SCOPE) {
            pageAttributes.remove(name);
        } else {
            rootJspCtxt.removeAttribute(name, scope);
        }
    }

    @Override
    public int getAttributesScope(String name) {

        if (name == null) {
            throw new NullPointerException(Localizer
                    .getMessage("jsp.error.attribute.null_name"));
        }

        if (pageAttributes.get(name) != null) {
            return PAGE_SCOPE;
        } else {
            return rootJspCtxt.getAttributesScope(name);
        }
    }

    @Override
    public Enumeration<String> getAttributeNamesInScope(int scope) {
        if (scope == PAGE_SCOPE) {
            return Collections.enumeration(pageAttributes.keySet());
        }

        return rootJspCtxt.getAttributeNamesInScope(scope);
    }

    @Override
    public void release() {
        invokingJspCtxt.release();
    }

    @Override
    public JspWriter getOut() {
        return rootJspCtxt.getOut();
    }

    @Override
    public HttpSession getSession() {
        return rootJspCtxt.getSession();
    }

    @Override
    public Object getPage() {
        return invokingJspCtxt.getPage();
    }

    @Override
    public ServletRequest getRequest() {
        return invokingJspCtxt.getRequest();
    }

    @Override
    public ServletResponse getResponse() {
        return rootJspCtxt.getResponse();
    }

    @Override
    public Exception getException() {
        return invokingJspCtxt.getException();
    }

    @Override
    public ServletConfig getServletConfig() {
        return invokingJspCtxt.getServletConfig();
    }

    @Override
    public ServletContext getServletContext() {
        if (servletContext == null) {
            servletContext = rootJspCtxt.getServletContext();
        }
        return servletContext;
    }

    @Override
    public void forward(String relativeUrlPath) throws ServletException,
            IOException {
        invokingJspCtxt.forward(relativeUrlPath);
    }

    @Override
    public void include(String relativeUrlPath) throws ServletException,
            IOException {
        invokingJspCtxt.include(relativeUrlPath);
    }

    @Override
    public void include(String relativeUrlPath, boolean flush)
            throws ServletException, IOException {
        invokingJspCtxt.include(relativeUrlPath, false);
    }

    @Override
    @Deprecated
    public VariableResolver getVariableResolver() {
        return this;
    }

    @Override
    public BodyContent pushBody() {
        return invokingJspCtxt.pushBody();
    }

    @Override
    public JspWriter pushBody(Writer writer) {
        return invokingJspCtxt.pushBody(writer);
    }

    @Override
    public JspWriter popBody() {
        return invokingJspCtxt.popBody();
    }

    @Override
    @Deprecated
    public ExpressionEvaluator getExpressionEvaluator() {
        return invokingJspCtxt.getExpressionEvaluator();
    }

    @Override
    public void handlePageException(Exception ex) throws IOException,
            ServletException {
        // Should never be called since handleException() called with a
        // Throwable in the generated servlet.
        handlePageException((Throwable) ex);
    }

    @Override
    public void handlePageException(Throwable t) throws IOException,
            ServletException {
        invokingJspCtxt.handlePageException(t);
    }

    /**
     * VariableResolver interface
     */
    @Override
    @Deprecated
    public Object resolveVariable(String pName) throws ELException {
        ELContext ctx = this.getELContext();
        return ctx.getELResolver().getValue(ctx, null, pName);
    }

    /**
     * Synchronize variables at begin of tag file
     */
    public void syncBeginTagFile() {
        saveNestedVariables();
    }

    /**
     * Synchronize variables before fragment invocation
     */
    public void syncBeforeInvoke() {
        copyTagToPageScope(VariableInfo.NESTED);
        copyTagToPageScope(VariableInfo.AT_BEGIN);
    }

    /**
     * Synchronize variables at end of tag file
     */
    public void syncEndTagFile() {
        copyTagToPageScope(VariableInfo.AT_BEGIN);
        copyTagToPageScope(VariableInfo.AT_END);
        restoreNestedVariables();
    }

    /**
     * Copies the variables of the given scope from the virtual page scope of
     * this JSP context wrapper to the page scope of the invoking JSP context.
     *
     * @param scope
     *            variable scope (one of NESTED, AT_BEGIN, or AT_END)
     */
    private void copyTagToPageScope(int scope) {
        Iterator<String> iter = null;

        switch (scope) {
        case VariableInfo.NESTED:
            if (nestedVars != null) {
                iter = nestedVars.iterator();
            }
            break;
        case VariableInfo.AT_BEGIN:
            if (atBeginVars != null) {
                iter = atBeginVars.iterator();
            }
            break;
        case VariableInfo.AT_END:
            if (atEndVars != null) {
                iter = atEndVars.iterator();
            }
            break;
        }

        while ((iter != null) && iter.hasNext()) {
            String varName = iter.next();
            Object obj = getAttribute(varName);
            varName = findAlias(varName);
            if (obj != null) {
                invokingJspCtxt.setAttribute(varName, obj);
            } else {
                invokingJspCtxt.removeAttribute(varName, PAGE_SCOPE);
            }
        }
    }

    /**
     * Saves the values of any NESTED variables that are present in the invoking
     * JSP context, so they can later be restored.
     */
    private void saveNestedVariables() {
        if (nestedVars != null) {
            for (String varName : nestedVars) {
                varName = findAlias(varName);
                Object obj = invokingJspCtxt.getAttribute(varName);
                if (obj != null) {
                    originalNestedVars.put(varName, obj);
                }
            }
        }
    }

    /**
     * Restores the values of any NESTED variables in the invoking JSP context.
     */
    private void restoreNestedVariables() {
        if (nestedVars != null) {
            for (String varName : nestedVars) {
                varName = findAlias(varName);
                Object obj = originalNestedVars.get(varName);
                if (obj != null) {
                    invokingJspCtxt.setAttribute(varName, obj);
                } else {
                    invokingJspCtxt.removeAttribute(varName, PAGE_SCOPE);
                }
            }
        }
    }

    /**
     * Checks to see if the given variable name is used as an alias, and if so,
     * returns the variable name for which it is used as an alias.
     *
     * @param varName
     *            The variable name to check
     * @return The variable name for which varName is used as an alias, or
     *         varName if it is not being used as an alias
     */
    private String findAlias(String varName) {

        if (aliases == null) {
            return varName;
        }

        String alias = aliases.get(varName);
        if (alias == null) {
            return varName;
        }
        return alias;
    }

    @Override
    public ELContext getELContext() {
        if (elContext == null) {
            elContext = new ELContextWrapper(rootJspCtxt.getELContext(), jspTag, this);
            JspFactory factory = JspFactory.getDefaultFactory();
            JspApplicationContext jspAppCtxt = factory.getJspApplicationContext(servletContext);
            if (jspAppCtxt instanceof JspApplicationContextImpl) {
                ((JspApplicationContextImpl) jspAppCtxt).fireListeners(elContext);
            }
        }
        return elContext;
    }

    static class ELContextWrapper extends ELContext {

        private final ELContext wrapped;
        private final JspTag jspTag;
        private final PageContext pageContext;
        private ImportHandler importHandler;

        private ELContextWrapper(ELContext wrapped, JspTag jspTag, PageContext pageContext) {
            this.wrapped = wrapped;
            this.jspTag = jspTag;
            this.pageContext = pageContext;
        }

        ELContext getWrappedELContext() {
            return wrapped;
        }

        @Override
        public void setPropertyResolved(boolean resolved) {
            wrapped.setPropertyResolved(resolved);
        }

        @Override
        public void setPropertyResolved(Object base, Object property) {
            wrapped.setPropertyResolved(base, property);
        }

        @Override
        public boolean isPropertyResolved() {
            return wrapped.isPropertyResolved();
        }

        @Override
        public void putContext(Class<?> key, Object contextObject) {
            if (key != JspContext.class) {
                wrapped.putContext(key, contextObject);
            }
        }

        @Override
        public Object getContext(Class<?> key) {
            if (key == JspContext.class) {
                return pageContext;
            }
            if (key == NotFoundELResolver.class) {
                if (jspTag instanceof JspSourceDirectives) {
                    return Boolean.valueOf(((JspSourceDirectives) jspTag).getErrorOnELNotFound());
                } else {
                    // returning Boolean.FALSE would have the same effect
                    return null;
                }
            }
            return wrapped.getContext(key);
        }

        @Override
        public ImportHandler getImportHandler() {
            if (importHandler == null) {
                importHandler = new ImportHandler();
                if (jspTag instanceof JspSourceImports) {
                    Set<String> packageImports = ((JspSourceImports) jspTag).getPackageImports();
                    if (packageImports != null) {
                        for (String packageImport : packageImports) {
                            importHandler.importPackage(packageImport);
                        }
                    }
                    Set<String> classImports = ((JspSourceImports) jspTag).getClassImports();
                    if (classImports != null) {
                        for (String classImport : classImports) {
                            importHandler.importClass(classImport);
                        }
                    }
                }

            }
            return importHandler;
        }

        @Override
        public Locale getLocale() {
            return wrapped.getLocale();
        }

        @Override
        public void setLocale(Locale locale) {
            wrapped.setLocale(locale);
        }

        @Override
        public void addEvaluationListener(EvaluationListener listener) {
            wrapped.addEvaluationListener(listener);
        }

        @Override
        public List<EvaluationListener> getEvaluationListeners() {
            return wrapped.getEvaluationListeners();
        }

        @Override
        public void notifyBeforeEvaluation(String expression) {
            wrapped.notifyBeforeEvaluation(expression);
        }

        @Override
        public void notifyAfterEvaluation(String expression) {
            wrapped.notifyAfterEvaluation(expression);
        }

        @Override
        public void notifyPropertyResolved(Object base, Object property) {
            wrapped.notifyPropertyResolved(base, property);
        }

        @Override
        public boolean isLambdaArgument(String name) {
            return wrapped.isLambdaArgument(name);
        }

        @Override
        public Object getLambdaArgument(String name) {
            return wrapped.getLambdaArgument(name);
        }

        @Override
        public void enterLambdaScope(Map<String, Object> arguments) {
            wrapped.enterLambdaScope(arguments);
        }

        @Override
        public void exitLambdaScope() {
            wrapped.exitLambdaScope();
        }

        @Override
        public <T> T convertToType(Object obj, Class<T> type) {
            return wrapped.convertToType(obj, type);
        }

        @Override
        public ELResolver getELResolver() {
            return wrapped.getELResolver();
        }

        @Override
        public FunctionMapper getFunctionMapper() {
            return wrapped.getFunctionMapper();
        }

        @Override
        public VariableMapper getVariableMapper() {
            return wrapped.getVariableMapper();
        }
    }
}

quality96%

¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤

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 ist noch experimentell.