/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* Licensed 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.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Enumeration;
import java.util.Hashtable;
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.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspFactory;
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 org.apache.commons.el.ExpressionEvaluatorImpl;
import org.apache.commons.el.VariableResolverImpl;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.jasper.Constants;
import org.apache.jasper.compiler.Localizer;
/**
* Implementation of the PageContext class from the JSP spec.
* Also doubles as a VariableResolver for the EL.
*
* @author Anil K. Vijendran
* @author Larry Cable
* @author Hans Bergsten
* @author Pierre Delisle
* @author Mark Roth
* @author Jan Luehe
*/
public class PageContextImpl extends PageContext implements VariableResolver {
// Logger
private static Log log = LogFactory.getLog(PageContextImpl.class);
// The expression evaluator, for evaluating EL expressions.
private static ExpressionEvaluatorImpl elExprEval
= new ExpressionEvaluatorImpl(false);
// The variable resolver, for evaluating EL expressions.
private VariableResolverImpl variableResolver;
private BodyContentImpl[] outs;
private int depth;
// per-servlet state
private Servlet servlet;
private ServletConfig config;
private ServletContext context;
private JspFactory factory;
private boolean needsSession;
private String errorPageURL;
private boolean autoFlush;
private int bufferSize;
// page-scope attributes
private transient Hashtable attributes;
// per-request state
private transient ServletRequest request;
private transient ServletResponse response;
private transient Object page;
private transient HttpSession session;
private boolean isIncluded;
// initial output stream
private transient JspWriter out;
private transient JspWriterImpl baseOut;
/*
* Constructor.
*/
PageContextImpl(JspFactory factory) {
this.factory = factory;
this.variableResolver = new VariableResolverImpl(this);
this.outs = new BodyContentImpl[0];
this.attributes = new Hashtable(16);
this.depth = -1;
}
public void initialize(Servlet servlet,
ServletRequest request,
ServletResponse response,
String errorPageURL,
boolean needsSession,
int bufferSize,
boolean autoFlush) throws IOException {
_initialize(servlet, request, response, errorPageURL, needsSession,
bufferSize, autoFlush);
}
private void _initialize(Servlet servlet,
ServletRequest request,
ServletResponse response,
String errorPageURL,
boolean needsSession,
int bufferSize,
boolean autoFlush) throws IOException {
// initialize state
this.servlet = servlet;
this.config = servlet.getServletConfig();
this.context = config.getServletContext();
this.needsSession = needsSession;
this.errorPageURL = errorPageURL;
this.bufferSize = bufferSize;
this.autoFlush = autoFlush;
this.request = request;
this.response = response;
// Setup session (if required)
if (request instanceof HttpServletRequest && needsSession)
this.session = ((HttpServletRequest)request).getSession();
if (needsSession && session == null)
throw new IllegalStateException
("Page needs a session and none is available");
// initialize the initial out ...
depth = -1;
if (this.baseOut == null) {
this.baseOut = new JspWriterImpl(response, bufferSize, autoFlush);
} else {
this.baseOut.init(response, bufferSize, autoFlush);
}
this.out = baseOut;
// register names/values as per spec
setAttribute(OUT, this.out);
setAttribute(REQUEST, request);
setAttribute(RESPONSE, response);
if (session != null)
setAttribute(SESSION, session);
setAttribute(PAGE, servlet);
setAttribute(CONFIG, config);
setAttribute(PAGECONTEXT, this);
setAttribute(APPLICATION, context);
isIncluded = request.getAttribute(
"javax.servlet.include.servlet_path") != null;
}
public void release() {
out = baseOut;
try {
if (isIncluded) {
((JspWriterImpl)out).flushBuffer();
// push it into the including jspWriter
} else {
// Old code:
//out.flush();
// Do not flush the buffer even if we're not included (i.e.
// we are the main page. The servlet will flush it and close
// the stream.
((JspWriterImpl)out).flushBuffer();
}
} catch (IOException ex) {
log.warn("Internal error flushing the buffer in release()");
}
servlet = null;
config = null;
context = null;
needsSession = false;
errorPageURL = null;
bufferSize = JspWriter.DEFAULT_BUFFER;
autoFlush = true;
request = null;
response = null;
depth = -1;
baseOut.recycle();
session = null;
attributes.clear();
}
public Object getAttribute(final String name) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
return AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
return doGetAttribute(name);
}
});
} else {
return doGetAttribute(name);
}
}
private Object doGetAttribute(String name){
return attributes.get(name);
}
public Object getAttribute(final String name, final int scope) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
return AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
return doGetAttribute(name, scope);
}
});
} else {
return doGetAttribute(name, scope);
}
}
private Object doGetAttribute(String name, int scope){
switch (scope) {
case PAGE_SCOPE:
return attributes.get(name);
case REQUEST_SCOPE:
return request.getAttribute(name);
case SESSION_SCOPE:
if (session == null) {
throw new IllegalStateException(
Localizer.getMessage("jsp.error.page.noSession"));
}
return session.getAttribute(name);
case APPLICATION_SCOPE:
return context.getAttribute(name);
default:
throw new IllegalArgumentException("Invalid scope");
}
}
public void setAttribute(final String name, final Object attribute) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
doSetAttribute(name, attribute);
return null;
}
});
} else {
doSetAttribute(name, attribute);
}
}
private void doSetAttribute(String name, Object attribute){
if (attribute != null) {
attributes.put(name, attribute);
} else {
removeAttribute(name, PAGE_SCOPE);
}
}
public void setAttribute(final String name, final Object o, final int scope) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
doSetAttribute(name, o, scope);
return null;
}
});
} else {
doSetAttribute(name, o, scope);
}
}
private void doSetAttribute(String name, Object o, int scope ){
if (o != null) {
switch (scope) {
case PAGE_SCOPE:
attributes.put(name, o);
break;
case REQUEST_SCOPE:
request.setAttribute(name, o);
break;
case SESSION_SCOPE:
if (session == null) {
throw new IllegalStateException(
Localizer.getMessage("jsp.error.page.noSession"));
}
session.setAttribute(name, o);
break;
case APPLICATION_SCOPE:
context.setAttribute(name, o);
break;
default:
throw new IllegalArgumentException("Invalid scope");
}
} else {
removeAttribute(name, scope);
}
}
public void removeAttribute(final String name, final int scope) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
doRemoveAttribute(name, scope);
return null;
}
});
} else {
doRemoveAttribute(name, scope);
}
}
private void doRemoveAttribute(String name, int scope){
switch (scope) {
case PAGE_SCOPE:
attributes.remove(name);
break;
case REQUEST_SCOPE:
request.removeAttribute(name);
break;
case SESSION_SCOPE:
if (session == null) {
throw new IllegalStateException(
Localizer.getMessage("jsp.error.page.noSession"));
}
session.removeAttribute(name);
break;
case APPLICATION_SCOPE:
context.removeAttribute(name);
break;
default:
throw new IllegalArgumentException("Invalid scope");
}
}
public int getAttributesScope(final String name) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
return ((Integer)AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
return new Integer(doGetAttributeScope(name));
}
})).intValue();
} else {
return doGetAttributeScope(name);
}
}
private int doGetAttributeScope(String name){
if (attributes.get(name) != null)
return PAGE_SCOPE;
if (request.getAttribute(name) != null)
return REQUEST_SCOPE;
if (session != null) {
if (session.getAttribute(name) != null)
return SESSION_SCOPE;
}
if (context.getAttribute(name) != null)
return APPLICATION_SCOPE;
return 0;
}
public Object findAttribute(final String name) {
if (System.getSecurityManager() != null){
return AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
return doFindAttribute(name);
}
});
} else {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
return doFindAttribute(name);
}
}
private Object doFindAttribute(String name){
Object o = attributes.get(name);
if (o != null)
return o;
o = request.getAttribute(name);
if (o != null)
return o;
if (session != null) {
o = session.getAttribute(name);
if (o != null)
return o;
}
return context.getAttribute(name);
}
public Enumeration getAttributeNamesInScope(final int scope) {
if (System.getSecurityManager() != null){
return (Enumeration)
AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
return doGetAttributeNamesInScope(scope);
}
});
} else {
return doGetAttributeNamesInScope(scope);
}
}
private Enumeration doGetAttributeNamesInScope(int scope){
switch (scope) {
case PAGE_SCOPE:
return attributes.keys();
case REQUEST_SCOPE:
return request.getAttributeNames();
case SESSION_SCOPE:
if (session == null) {
throw new IllegalStateException(
Localizer.getMessage("jsp.error.page.noSession"));
}
return session.getAttributeNames();
case APPLICATION_SCOPE:
return context.getAttributeNames();
default:
throw new IllegalArgumentException("Invalid scope");
}
}
public void removeAttribute(final String name) {
if (name == null) {
throw new NullPointerException(
Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (System.getSecurityManager() != null){
AccessController.doPrivileged(new PrivilegedAction(){
public Object run(){
doRemoveAttribute(name);
return null;
}
});
} else {
doRemoveAttribute(name);
}
}
private void doRemoveAttribute(String name){
try {
removeAttribute(name, PAGE_SCOPE);
removeAttribute(name, REQUEST_SCOPE);
if( session != null ) {
removeAttribute(name, SESSION_SCOPE);
}
removeAttribute(name, APPLICATION_SCOPE);
} catch (Exception ex) {
// we remove as much as we can, and
// simply ignore possible exceptions
}
}
public JspWriter getOut() {
return out;
}
public HttpSession getSession() { return session; }
public Servlet getServlet() { return servlet; }
public ServletConfig getServletConfig() { return config; }
public ServletContext getServletContext() {
return config.getServletContext();
}
public ServletRequest getRequest() { return request; }
public ServletResponse getResponse() { return response; }
public Exception getException() { return (Exception)request.getAttribute(EXCEPTION); }
public Object getPage() { return servlet; }
private final String getAbsolutePathRelativeToContext(String relativeUrlPath) {
String path = relativeUrlPath;
if (!path.startsWith("/")) {
String uri = (String)
request.getAttribute("javax.servlet.include.servlet_path");
if (uri == null)
uri = ((HttpServletRequest) request).getServletPath();
String baseURI = uri.substring(0, uri.lastIndexOf('/'));
path = baseURI+'/'+path;
}
return path;
}
public void include(String relativeUrlPath)
throws ServletException, IOException {
JspRuntimeLibrary.include(request, response, relativeUrlPath, out,
true);
}
public void include(final String relativeUrlPath, final boolean flush)
throws ServletException, IOException {
if (System.getSecurityManager() != null){
try{
AccessController.doPrivileged(new PrivilegedExceptionAction(){
public Object run() throws Exception{
doInclude(relativeUrlPath, flush);
return null;
}
});
} catch (PrivilegedActionException e){
Exception ex = e.getException();
if (ex instanceof IOException){
throw (IOException)ex;
} else {
throw (ServletException)ex;
}
}
} else {
doInclude(relativeUrlPath, flush);
}
}
private void doInclude(String relativeUrlPath, boolean flush)
throws ServletException, IOException {
JspRuntimeLibrary.include(request, response, relativeUrlPath, out,
flush);
}
public VariableResolver getVariableResolver() {
return this;
}
public void forward(final String relativeUrlPath)
throws ServletException, IOException {
if (System.getSecurityManager() != null){
try{
AccessController.doPrivileged(new PrivilegedExceptionAction(){
public Object run() throws Exception{
doForward(relativeUrlPath);
return null;
}
});
} catch (PrivilegedActionException e){
Exception ex = e.getException();
if (ex instanceof IOException){
throw (IOException)ex;
} else {
throw (ServletException)ex;
}
}
} else {
doForward(relativeUrlPath);
}
}
private void doForward(String relativeUrlPath)
throws ServletException, IOException{
// JSP.4.5 If the buffer was flushed, throw IllegalStateException
try {
out.clear();
} catch (IOException ex) {
throw new IllegalStateException(
Localizer.getMessage("jsp.error.attempt_to_clear_flushed_buffer"));
}
// Make sure that the response object is not the wrapper for include
while (response instanceof ServletResponseWrapperInclude) {
response = ((ServletResponseWrapperInclude)response).getResponse();
}
final String path = getAbsolutePathRelativeToContext(relativeUrlPath);
String includeUri
= (String) request.getAttribute(Constants.INC_SERVLET_PATH);
final ServletResponse fresponse = response;
final ServletRequest frequest = request;
if (includeUri != null)
request.removeAttribute(Constants.INC_SERVLET_PATH);
try {
context.getRequestDispatcher(path).forward(request, response);
} finally {
if (includeUri != null)
request.setAttribute(Constants.INC_SERVLET_PATH, includeUri);
request.setAttribute(Constants.FORWARD_SEEN, "true");
}
}
public BodyContent pushBody() {
return (BodyContent) pushBody(null);
}
public JspWriter pushBody(Writer writer) {
depth++;
if (depth >= outs.length) {
BodyContentImpl[] newOuts = new BodyContentImpl[depth + 1];
for (int i=0; i<outs.length; i++) {
newOuts[i] = outs[i];
}
newOuts[depth] = new BodyContentImpl(out);
outs = newOuts;
}
outs[depth].setWriter(writer);
out = outs[depth];
// Update the value of the "out" attribute in the page scope
// attribute namespace of this PageContext
setAttribute(OUT, out);
return outs[depth];
}
public JspWriter popBody() {
depth--;
if (depth >= 0) {
out = outs[depth];
} else {
out = baseOut;
}
// Update the value of the "out" attribute in the page scope
// attribute namespace of this PageContext
setAttribute(OUT, out);
return out;
}
/**
* Provides programmatic access to the ExpressionEvaluator.
* The JSP Container must return a valid instance of an
* ExpressionEvaluator that can parse EL expressions.
*/
public ExpressionEvaluator getExpressionEvaluator() {
return elExprEval;
}
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(final Throwable t)
throws IOException, ServletException
{
if (t == null)
throw new NullPointerException("null Throwable");
if (System.getSecurityManager() != null){
try{
AccessController.doPrivileged(new PrivilegedExceptionAction(){
public Object run() throws Exception{
doHandlePageException(t);
return null;
}
});
} catch (PrivilegedActionException e){
Exception ex = e.getException();
if (ex instanceof IOException){
throw (IOException)ex;
} else {
throw (ServletException)ex;
}
}
} else {
doHandlePageException(t);
}
}
private void doHandlePageException(Throwable t)
throws IOException, ServletException {
if (errorPageURL != null && !errorPageURL.equals("")) {
/*
* Set request attributes.
* Do not set the javax.servlet.error.exception attribute here
* (instead, set in the generated servlet code for the error page)
* in order to prevent the ErrorReportValve, which is invoked as
* part of forwarding the request to the error page, from
* throwing it if the response has not been committed (the response
* will have been committed if the error page is a JSP page).
*/
request.setAttribute("javax.servlet.jsp.jspException", t);
request.setAttribute("javax.servlet.error.status_code",
new Integer(HttpServletResponse.SC_INTERNAL_SERVER_ERROR));
request.setAttribute("javax.servlet.error.request_uri",
((HttpServletRequest) request).getRequestURI());
request.setAttribute("javax.servlet.error.servlet_name",
config.getServletName());
try {
forward(errorPageURL);
} catch (IllegalStateException ise) {
include(errorPageURL);
}
// The error page could be inside an include.
Object newException = request.getAttribute("javax.servlet.error.exception");
// t==null means the attribute was not set.
if( (newException!= null) && (newException==t) ) {
request.removeAttribute("javax.servlet.error.exception");
}
// now clear the error code - to prevent double handling.
request.removeAttribute("javax.servlet.error.status_code");
request.removeAttribute("javax.servlet.error.request_uri");
request.removeAttribute("javax.servlet.error.status_code");
request.removeAttribute("javax.servlet.jsp.jspException");
} else {
// Otherwise throw the exception wrapped inside a ServletException.
// Set the exception as the root cause in the ServletException
// to get a stack trace for the real problem
if (t instanceof IOException) throw (IOException)t;
if (t instanceof ServletException) throw (ServletException)t;
if (t instanceof RuntimeException) throw (RuntimeException)t;
Throwable rootCause = null;
if (t instanceof JspException) {
rootCause = ((JspException) t).getRootCause();
} else if (t instanceof ELException) {
rootCause = ((ELException) t).getRootCause();
}
if (rootCause != null) {
throw new ServletException(t.getMessage(), rootCause);
}
throw new ServletException(t);
}
}
/**
* VariableResolver interface
*/
public Object resolveVariable(String pName) throws ELException {
return variableResolver.resolveVariable(pName);
}
private static String XmlEscape(String s) {
if (s == null) return null;
StringBuffer sb = new StringBuffer();
for(int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '<') {
sb.append("<");
} else if (c == '>') {
sb.append(">");
} else if (c == '\'') {
sb.append("'"); // '
} else if (c == '&') {
sb.append("&");
} else if (c == '"') {
sb.append("""); // "
} else {
sb.append(c);
}
}
return sb.toString();
}
/**
* Proprietary method to evaluate EL expressions.
* XXX - This method should go away once the EL interpreter moves
* out of JSTL and into its own project. For now, this is necessary
* because the standard machinery is too slow.
*
* @param expression The expression to be evaluated
* @param expectedType The expected resulting type
* @param pageContext The page context
* @param functionMap Maps prefix and name to Method
* @return The result of the evaluation
*/
public static Object proprietaryEvaluate(final String expression,
final Class expectedType,
final PageContext pageContext,
final ProtectedFunctionMapper functionMap,
final boolean escape)
throws ELException
{
Object retValue;
if (System.getSecurityManager() != null){
try {
retValue = AccessController.doPrivileged(
new PrivilegedExceptionAction(){
public Object run() throws Exception{
return elExprEval.evaluate(expression,
expectedType,
pageContext.getVariableResolver(),
functionMap);
}
});
} catch (PrivilegedActionException ex) {
Exception realEx = ex.getException();
if (realEx instanceof ELException) {
throw (ELException) realEx;
} else {
throw new ELException(realEx);
}
}
} else {
retValue = elExprEval.evaluate(expression,
expectedType,
pageContext.getVariableResolver(),
functionMap);
}
if (escape) {
retValue = XmlEscape(retValue.toString());
}
return retValue;
}
}