jasper/src/share/org/apache/jasper/runtime/JspContextWrapper.java - tomcat55 - Git at Google

 /*
  * 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.Enumeration;
 import java.util.Hashtable;
 import java.util.Iterator;
 import java.util.Map;

 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpSession;
 import javax.servlet.jsp.JspContext;
 import javax.servlet.jsp.JspWriter;
 import javax.servlet.jsp.PageContext;
 import javax.servlet.jsp.el.ELException;
 import javax.servlet.jsp.el.ExpressionEvaluator;
 import javax.servlet.jsp.el.VariableResolver;
 import javax.servlet.jsp.tagext.BodyContent;
 import javax.servlet.jsp.tagext.VariableInfo;

 import org.apache.commons.el.VariableResolverImpl;
 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
  */
 public class JspContextWrapper
             extends PageContext implements VariableResolver {

     // Invoking JSP context
     private PageContext invokingJspCtxt;

     private transient Hashtable	pageAttributes;

     // ArrayList of NESTED scripting variables
     private ArrayList nestedVars;

     // ArrayList of AT_BEGIN scripting variables
     private ArrayList atBeginVars;

     // ArrayList of AT_END scripting variables
     private ArrayList atEndVars;

     private Map aliases;

     private Hashtable originalNestedVars;

     /**
      * The variable resolver, for evaluating EL expressions.
      */
     private VariableResolverImpl variableResolver
         = new VariableResolverImpl(this);

     public JspContextWrapper(JspContext jspContext, ArrayList nestedVars,
 			     ArrayList atBeginVars, ArrayList atEndVars,
 			     Map aliases) {
         this.invokingJspCtxt = (PageContext) jspContext;
 	this.nestedVars = nestedVars;
 	this.atBeginVars = atBeginVars;
 	this.atEndVars = atEndVars;
 	this.pageAttributes = new Hashtable(16);
 	this.aliases = aliases;

 	if (nestedVars != null) {
 	    this.originalNestedVars = new Hashtable(nestedVars.size());
 	}
 	syncBeginTagFile();
     }

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

     public Object getAttribute(String name) {

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

 	return pageAttributes.get(name);
     }

     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 invokingJspCtxt.getAttribute(name, scope);
     }

     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);
 	}
     }

     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 {
 	    invokingJspCtxt.setAttribute(name, value, scope);
 	}
     }

     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 = invokingJspCtxt.getAttribute(name, REQUEST_SCOPE);
 	    if (o == null) {
 		if (getSession() != null) {
 		    o = invokingJspCtxt.getAttribute(name, SESSION_SCOPE);
 		}
 		if (o == null) {
 		    o = invokingJspCtxt.getAttribute(name, APPLICATION_SCOPE);
 		}
 	    }
 	}

 	return o;
     }

     public void removeAttribute(String name) {

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

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

     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 {
 	    invokingJspCtxt.removeAttribute(name, scope);
 	}
     }

     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 invokingJspCtxt.getAttributesScope(name);
 	}
     }

     public Enumeration getAttributeNamesInScope(int scope) {
         if (scope == PAGE_SCOPE) {
             return pageAttributes.keys();
 	}

 	return invokingJspCtxt.getAttributeNamesInScope(scope);
     }

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

     public JspWriter getOut() {
 	return invokingJspCtxt.getOut();
     }

     public HttpSession getSession() {
 	return invokingJspCtxt.getSession();
     }

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

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

     public ServletResponse getResponse() {
 	return invokingJspCtxt.getResponse();
     }

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

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

     public ServletContext getServletContext() {
 	return invokingJspCtxt.getServletContext();
     }

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

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

     public void include(String relativeUrlPath, boolean flush)
 	    throws ServletException, IOException {
 	include(relativeUrlPath, false); // XXX
     }

     public VariableResolver getVariableResolver() {
 	return this;
     }

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

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

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

     public ExpressionEvaluator getExpressionEvaluator() {
 	return invokingJspCtxt.getExpressionEvaluator();
     }

     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);
     }

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

     /**
      * VariableResolver interface
      */
     public Object resolveVariable( String pName ) throws ELException
     {
         return variableResolver.resolveVariable(pName);
     }

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

     /**
      * Synchronize variables before fragment invokation
      */
     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 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 = (String) 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) {
 	    Iterator iter = nestedVars.iterator();
 	    while (iter.hasNext()) {
 		String varName = (String) iter.next();
 		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) {
 	    Iterator iter = nestedVars.iterator();
 	    while (iter.hasNext()) {
 		String varName = (String) iter.next();
 		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 = (String) aliases.get(varName);
 	if (alias == null) {
 	    return varName;
 	}
 	return alias;
     }
 }
	/*
	* 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.Enumeration;
	import java.util.Hashtable;
	import java.util.Iterator;
	import java.util.Map;

	import javax.servlet.Servlet;
	import javax.servlet.ServletConfig;
	import javax.servlet.ServletContext;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpSession;
	import javax.servlet.jsp.JspContext;
	import javax.servlet.jsp.JspWriter;
	import javax.servlet.jsp.PageContext;
	import javax.servlet.jsp.el.ELException;
	import javax.servlet.jsp.el.ExpressionEvaluator;
	import javax.servlet.jsp.el.VariableResolver;
	import javax.servlet.jsp.tagext.BodyContent;
	import javax.servlet.jsp.tagext.VariableInfo;

	import org.apache.commons.el.VariableResolverImpl;
	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
	*/
	public class JspContextWrapper
	extends PageContext implements VariableResolver {

	// Invoking JSP context
	private PageContext invokingJspCtxt;

	private transient Hashtable pageAttributes;

	// ArrayList of NESTED scripting variables
	private ArrayList nestedVars;

	// ArrayList of AT_BEGIN scripting variables
	private ArrayList atBeginVars;

	// ArrayList of AT_END scripting variables
	private ArrayList atEndVars;

	private Map aliases;

	private Hashtable originalNestedVars;

	/**
	* The variable resolver, for evaluating EL expressions.
	*/
	private VariableResolverImpl variableResolver
	= new VariableResolverImpl(this);

	public JspContextWrapper(JspContext jspContext, ArrayList nestedVars,
	ArrayList atBeginVars, ArrayList atEndVars,
	Map aliases) {
	this.invokingJspCtxt = (PageContext) jspContext;
	this.nestedVars = nestedVars;
	this.atBeginVars = atBeginVars;
	this.atEndVars = atEndVars;
	this.pageAttributes = new Hashtable(16);
	this.aliases = aliases;

	if (nestedVars != null) {
	this.originalNestedVars = new Hashtable(nestedVars.size());
	}
	syncBeginTagFile();
	}

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

	public Object getAttribute(String name) {

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

	return pageAttributes.get(name);
	}

	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 invokingJspCtxt.getAttribute(name, scope);
	}

	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);
	}
	}

	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 {
	invokingJspCtxt.setAttribute(name, value, scope);
	}
	}

	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 = invokingJspCtxt.getAttribute(name, REQUEST_SCOPE);
	if (o == null) {
	if (getSession() != null) {
	o = invokingJspCtxt.getAttribute(name, SESSION_SCOPE);
	}
	if (o == null) {
	o = invokingJspCtxt.getAttribute(name, APPLICATION_SCOPE);
	}
	}
	}

	return o;
	}

	public void removeAttribute(String name) {

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

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

	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 {
	invokingJspCtxt.removeAttribute(name, scope);
	}
	}

	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 invokingJspCtxt.getAttributesScope(name);
	}
	}

	public Enumeration getAttributeNamesInScope(int scope) {
	if (scope == PAGE_SCOPE) {
	return pageAttributes.keys();
	}

	return invokingJspCtxt.getAttributeNamesInScope(scope);
	}

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

	public JspWriter getOut() {
	return invokingJspCtxt.getOut();
	}

	public HttpSession getSession() {
	return invokingJspCtxt.getSession();
	}

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

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

	public ServletResponse getResponse() {
	return invokingJspCtxt.getResponse();
	}

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

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

	public ServletContext getServletContext() {
	return invokingJspCtxt.getServletContext();
	}

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

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

	public void include(String relativeUrlPath, boolean flush)
	throws ServletException, IOException {
	include(relativeUrlPath, false); // XXX
	}

	public VariableResolver getVariableResolver() {
	return this;
	}

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

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

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

	public ExpressionEvaluator getExpressionEvaluator() {
	return invokingJspCtxt.getExpressionEvaluator();
	}

	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);
	}

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

	/**
	* VariableResolver interface
	*/
	public Object resolveVariable( String pName ) throws ELException
	{
	return variableResolver.resolveVariable(pName);
	}

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

	/**
	* Synchronize variables before fragment invokation
	*/
	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 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 = (String) 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) {
	Iterator iter = nestedVars.iterator();
	while (iter.hasNext()) {
	String varName = (String) iter.next();
	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) {
	Iterator iter = nestedVars.iterator();
	while (iter.hasNext()) {
	String varName = (String) iter.next();
	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 = (String) aliases.get(varName);
	if (alias == null) {
	return varName;
	}
	return alias;
	}
	}