/*
* 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.Locale;
import java.util.Map;
import javax.el.ELContext;
import javax.el.ELResolver;
import javax.el.FunctionMapper;
import javax.el.VariableMapper;
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.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
*/
public class JspContextWrapper extends PageContext implements VariableResolver {
// Invoking JSP context
private PageContext invokingJspCtxt;
private transient HashMap<String, Object> pageAttributes;
// ArrayList of NESTED scripting variables
private ArrayList<String> nestedVars;
// ArrayList of AT_BEGIN scripting variables
private ArrayList<String> atBeginVars;
// ArrayList of AT_END scripting variables
private ArrayList<String> atEndVars;
private Map<String,String> aliases;
private HashMap<String, Object> originalNestedVars;
private ServletContext servletContext = null;
private ELContext elContext = null;
private PageContext rootJspCtxt;
public JspContextWrapper(JspContext jspContext,
ArrayList<String> nestedVars, ArrayList<String> atBeginVars,
ArrayList<String> atEndVars, Map<String,String> aliases) {
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<String, Object>(16);
this.aliases = aliases;
if (nestedVars != null) {
this.originalNestedVars = new HashMap<String, Object>(nestedVars.size());
}
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) {
o = rootJspCtxt.getAttribute(name, SESSION_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) {
Iterator<String> iter = nestedVars.iterator();
while (iter.hasNext()) {
String varName = 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<String> iter = nestedVars.iterator();
while (iter.hasNext()) {
String varName = 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 = aliases.get(varName);
if (alias == null) {
return varName;
}
return alias;
}
@Override
public ELContext getELContext() {
if (elContext == null) {
elContext = new ELContextWrapper(rootJspCtxt.getELContext(), this);
}
return elContext;
}
static class ELContextWrapper extends ELContext {
private final ELContext wrapped;
private final PageContext pageContext;
private ELContextWrapper(ELContext wrapped, PageContext pageContext) {
this.wrapped = wrapped;
this.pageContext = pageContext;
}
ELContext getWrappedELContext() {
return wrapped;
}
@Override
public void setPropertyResolved(boolean resolved) {
wrapped.setPropertyResolved(resolved);
}
@Override
public boolean isPropertyResolved() {
return wrapped.isPropertyResolved();
}
@Override
public void putContext(@SuppressWarnings("rawtypes") Class key, Object contextObject) {
wrapped.putContext(key, contextObject);
}
@Override
public Object getContext(@SuppressWarnings("rawtypes") Class key) {
if (key == JspContext.class) {
return pageContext;
}
return wrapped.getContext(key);
}
@Override
public Locale getLocale() {
return wrapped.getLocale();
}
@Override
public void setLocale(Locale locale) {
wrapped.setLocale(locale);
}
@Override
public ELResolver getELResolver() {
return wrapped.getELResolver();
}
@Override
public FunctionMapper getFunctionMapper() {
return wrapped.getFunctionMapper();
}
@Override
public VariableMapper getVariableMapper() {
return wrapped.getVariableMapper();
}
}
}