PageContextImpl.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.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Set;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ExpressionFactory;
import javax.el.ImportHandler;
import javax.el.ValueExpression;
import javax.servlet.RequestDispatcher;
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.tagext.BodyContent;
import org.apache.jasper.Constants;
import org.apache.jasper.compiler.Localizer;
import org.apache.jasper.el.ELContextImpl;
import org.apache.jasper.runtime.JspContextWrapper.ELContextWrapper;
/**
* 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
* @author Jacob Hookom
*/
public class PageContextImpl extends PageContext {
private static final JspFactory jspf = JspFactory.getDefaultFactory();
private static final BodyContentImpl[] EMPTY_BODY_CONTENT_IMPL_ARRAY = new BodyContentImpl[0];
private BodyContentImpl[] outs;
private int depth;
// per-servlet state
private Servlet servlet;
private ServletConfig config;
private ServletContext context;
private JspApplicationContextImpl applicationContext;
private String errorPageURL;
// page-scope attributes
private final transient HashMap<String, Object> attributes;
// per-request state
private transient ServletRequest request;
private transient ServletResponse response;
private transient HttpSession session;
private transient ELContextImpl elContext;
// initial output stream
private transient JspWriter out;
private transient JspWriterImpl baseOut;
PageContextImpl() {
this.outs = EMPTY_BODY_CONTENT_IMPL_ARRAY;
this.attributes = new HashMap<>(16);
this.depth = -1;
}
@Override
public 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.errorPageURL = errorPageURL;
this.request = request;
this.response = response;
// initialize application context
this.applicationContext = JspApplicationContextImpl.getInstance(context);
// Setup session (if required)
if (request instanceof HttpServletRequest && needsSession) {
this.session = ((HttpServletRequest) request).getSession();
}
if (needsSession && session == null) {
throw new IllegalStateException(Localizer.getMessage("jsp.error.page.sessionRequired"));
}
// initialize the initial out ...
depth = -1;
if (bufferSize == JspWriter.DEFAULT_BUFFER) {
bufferSize = Constants.DEFAULT_BUFFER_SIZE;
}
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);
}
@Override
public void release() {
out = baseOut;
try {
((JspWriterImpl) out).flushBuffer();
} catch (IOException ex) {
IllegalStateException ise = new IllegalStateException(Localizer.getMessage("jsp.error.flush"), ex);
throw ise;
} finally {
servlet = null;
config = null;
context = null;
applicationContext = null;
elContext = null;
errorPageURL = null;
request = null;
response = null;
depth = -1;
baseOut.recycle();
session = null;
attributes.clear();
for (BodyContentImpl body: outs) {
body.recycle();
}
}
}
@Override
public Object getAttribute(final String name) {
return getAttribute(name, PAGE_SCOPE);
}
@Override
public Object getAttribute(final String name, final int scope) {
if (name == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.attribute.null_name"));
}
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(Localizer.getMessage("jsp.error.page.invalid.scope"));
}
}
@Override
public void setAttribute(final String name, final Object attribute) {
setAttribute(name, attribute, PAGE_SCOPE);
}
@Override
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 (o == null) {
removeAttribute(name, scope);
} else {
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(Localizer.getMessage("jsp.error.page.invalid.scope"));
}
}
}
@Override
public void removeAttribute(final String name, final int scope) {
if (name == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.attribute.null_name"));
}
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(Localizer.getMessage("jsp.error.page.invalid.scope"));
}
}
@Override
public int getAttributesScope(final String name) {
if (name == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.attribute.null_name"));
}
if (attributes.get(name) != null) {
return PAGE_SCOPE;
}
if (request.getAttribute(name) != null) {
return REQUEST_SCOPE;
}
if (session != null) {
try {
if (session.getAttribute(name) != null) {
return SESSION_SCOPE;
}
} catch(IllegalStateException ise) {
// Session has been invalidated.
// Ignore and fall through to application scope.
}
}
if (context.getAttribute(name) != null) {
return APPLICATION_SCOPE;
}
return 0;
}
@Override
public Object findAttribute(final String name) {
if (name == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.attribute.null_name"));
}
Object o = attributes.get(name);
if (o != null) {
return o;
}
o = request.getAttribute(name);
if (o != null) {
return o;
}
if (session != null) {
try {
o = session.getAttribute(name);
} catch(IllegalStateException ise) {
// Session has been invalidated.
// Ignore and fall through to application scope.
}
if (o != null) {
return o;
}
}
return context.getAttribute(name);
}
@Override
public Enumeration<String> getAttributeNamesInScope(final int scope) {
switch (scope) {
case PAGE_SCOPE:
return Collections.enumeration(attributes.keySet());
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(Localizer.getMessage("jsp.error.page.invalid.scope"));
}
}
@Override
public void removeAttribute(final String name) {
if (name == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.attribute.null_name"));
}
removeAttribute(name, PAGE_SCOPE);
removeAttribute(name, REQUEST_SCOPE);
if( session != null ) {
try {
removeAttribute(name, SESSION_SCOPE);
} catch(IllegalStateException ise) {
// Session has been invalidated.
// Ignore and fall throw to application scope.
}
}
removeAttribute(name, APPLICATION_SCOPE);
}
@Override
public JspWriter getOut() {
return out;
}
@Override
public HttpSession getSession() {
return session;
}
@Override
public ServletConfig getServletConfig() {
return config;
}
@Override
public ServletContext getServletContext() {
return config.getServletContext();
}
@Override
public ServletRequest getRequest() {
return request;
}
@Override
public ServletResponse getResponse() {
return response;
}
/**
* Returns the exception associated with this page context, if any.
* <p>
* Added wrapping for Throwables to avoid ClassCastException: see Bugzilla
* 31171 for details.
*
* @return The Exception associated with this page context, if any.
*/
@Override
public Exception getException() {
Throwable t = JspRuntimeLibrary.getThrowable(request);
// Only wrap if needed
if ((t != null) && (!(t instanceof Exception))) {
t = new JspException(t);
}
return (Exception) t;
}
@Override
public Object getPage() {
return servlet;
}
private String getAbsolutePathRelativeToContext(String relativeUrlPath) {
String path = relativeUrlPath;
if (!path.startsWith("/")) {
String uri = (String) request.getAttribute(
RequestDispatcher.INCLUDE_SERVLET_PATH);
if (uri == null) {
uri = ((HttpServletRequest) request).getServletPath();
}
String baseURI = uri.substring(0, uri.lastIndexOf('/'));
path = baseURI + '/' + path;
}
return path;
}
@Override
public void include(String relativeUrlPath) throws ServletException,
IOException {
JspRuntimeLibrary
.include(request, response, relativeUrlPath, out, true);
}
@Override
public void include(final String relativeUrlPath, final boolean flush)
throws ServletException, IOException {
JspRuntimeLibrary.include(request, response, relativeUrlPath, out, flush);
}
@Override
@Deprecated
public javax.servlet.jsp.el.VariableResolver getVariableResolver() {
return new org.apache.jasper.el.VariableResolverImpl(
this.getELContext());
}
@Override
public void forward(final String relativeUrlPath) throws ServletException, IOException {
// JSP.4.5 If the buffer was flushed, throw IllegalStateException
try {
out.clear();
baseOut.clear();
} catch (IOException ex) {
throw new IllegalStateException(Localizer.getMessage(
"jsp.error.attempt_to_clear_flushed_buffer"), ex);
}
// 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(RequestDispatcher.INCLUDE_SERVLET_PATH);
if (includeUri != null) {
request.removeAttribute(RequestDispatcher.INCLUDE_SERVLET_PATH);
}
try {
context.getRequestDispatcher(path).forward(request, response);
} finally {
if (includeUri != null) {
request.setAttribute(RequestDispatcher.INCLUDE_SERVLET_PATH, includeUri);
}
}
}
@Override
public BodyContent pushBody() {
return (BodyContent) pushBody(null);
}
@Override
public JspWriter pushBody(Writer writer) {
depth++;
if (depth >= outs.length) {
BodyContentImpl[] newOuts = Arrays.copyOf(outs, depth + 1);
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];
}
@Override
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.
*/
@Override
@Deprecated
public javax.servlet.jsp.el.ExpressionEvaluator getExpressionEvaluator() {
return new org.apache.jasper.el.ExpressionEvaluatorImpl(
this.applicationContext.getExpressionFactory());
}
@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
@SuppressWarnings("deprecation") // Still have to support old JSP EL
public void handlePageException(final Throwable t) throws IOException, ServletException {
if (t == null) {
throw new NullPointerException(Localizer.getMessage("jsp.error.page.nullThrowable"));
}
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(EXCEPTION, t);
request.setAttribute(RequestDispatcher.ERROR_STATUS_CODE,
Integer.valueOf(HttpServletResponse.SC_INTERNAL_SERVER_ERROR));
request.setAttribute(RequestDispatcher.ERROR_REQUEST_URI, ((HttpServletRequest) request).getRequestURI());
request.setAttribute(RequestDispatcher.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(RequestDispatcher.ERROR_EXCEPTION);
// t==null means the attribute was not set.
if ((newException != null) && (newException == t)) {
request.removeAttribute(RequestDispatcher.ERROR_EXCEPTION);
}
// now clear the error code - to prevent double handling.
request.removeAttribute(RequestDispatcher.ERROR_STATUS_CODE);
request.removeAttribute(RequestDispatcher.ERROR_REQUEST_URI);
request.removeAttribute(RequestDispatcher.ERROR_SERVLET_NAME);
request.removeAttribute(EXCEPTION);
} 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 || t instanceof ELException ||
t instanceof javax.servlet.jsp.el.ELException) {
rootCause = t.getCause();
}
if (rootCause != null) {
throw new ServletException(
t.getClass().getName() + ": " + t.getMessage(), rootCause);
}
throw new ServletException(t);
}
}
/**
* 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
* @throws ELException If an error occurs during the evaluation
*/
public static Object proprietaryEvaluate(final String expression,
final Class<?> expectedType, final PageContext pageContext,
final ProtectedFunctionMapper functionMap)
throws ELException {
final ExpressionFactory exprFactory = jspf.getJspApplicationContext(pageContext.getServletContext()).getExpressionFactory();
ELContext ctx = pageContext.getELContext();
ELContextImpl ctxImpl;
if (ctx instanceof ELContextWrapper) {
ctxImpl = (ELContextImpl) ((ELContextWrapper) ctx).getWrappedELContext();
} else {
ctxImpl = (ELContextImpl) ctx;
}
ctxImpl.setFunctionMapper(functionMap);
ValueExpression ve = exprFactory.createValueExpression(ctx, expression, expectedType);
return ve.getValue(ctx);
}
@Override
public ELContext getELContext() {
if (elContext == null) {
elContext = applicationContext.createELContext(this);
if (servlet instanceof JspSourceImports) {
ImportHandler ih = elContext.getImportHandler();
Set<String> packageImports = ((JspSourceImports) servlet).getPackageImports();
if (packageImports != null) {
for (String packageImport : packageImports) {
ih.importPackage(packageImport);
}
}
Set<String> classImports = ((JspSourceImports) servlet).getClassImports();
if (classImports != null) {
for (String classImport : classImports) {
if (classImport.startsWith("static ")) {
classImport = classImport.substring(7);
try {
ih.importStatic(classImport);
} catch (ELException e) {
// Ignore - not all static imports are valid for EL
}
} else {
ih.importClass(classImport);
}
}
}
}
}
return this.elContext;
}
}