/*
* 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.servlet;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.SingleThreadModel;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.tagext.TagInfo;
import org.apache.AnnotationProcessor;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.Options;
import org.apache.jasper.compiler.ErrorDispatcher;
import org.apache.jasper.compiler.JavacErrorDetail;
import org.apache.jasper.compiler.JspRuntimeContext;
import org.apache.jasper.compiler.Localizer;
import org.apache.jasper.runtime.JspSourceDependent;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
/**
* The JSP engine (a.k.a Jasper).
*
* The servlet container is responsible for providing a
* URLClassLoader for the web application context Jasper
* is being used in. Jasper will try get the Tomcat
* ServletContext attribute for its ServletContext class
* loader, if that fails, it uses the parent class loader.
* In either case, it must be a URLClassLoader.
*
* @author Anil K. Vijendran
* @author Harish Prabandham
* @author Remy Maucherat
* @author Kin-man Chung
* @author Glenn Nielsen
* @author Tim Fennell
*/
public class JspServletWrapper {
// Logger
private Log log = LogFactory.getLog(JspServletWrapper.class);
private Servlet theServlet;
private String jspUri;
private Class servletClass;
private Class tagHandlerClass;
private JspCompilationContext ctxt;
private long available = 0L;
private ServletConfig config;
private Options options;
private boolean firstTime = true;
/** Whether the servlet needs reloading on next access */
private volatile boolean reload = true;
private boolean isTagFile;
private int tripCount;
private JasperException compileException;
/** Timestamp of last time servlet resource was modified */
private volatile long servletClassLastModifiedTime;
private long lastModificationTest = 0L;
/*
* JspServletWrapper for JSP pages.
*/
public JspServletWrapper(ServletConfig config, Options options, String jspUri,
boolean isErrorPage, JspRuntimeContext rctxt)
throws JasperException {
this.isTagFile = false;
this.config = config;
this.options = options;
this.jspUri = jspUri;
ctxt = new JspCompilationContext(jspUri, isErrorPage, options,
config.getServletContext(),
this, rctxt);
}
/*
* JspServletWrapper for tag files.
*/
public JspServletWrapper(ServletContext servletContext,
Options options,
String tagFilePath,
TagInfo tagInfo,
JspRuntimeContext rctxt,
URL tagFileJarUrl)
throws JasperException {
this.isTagFile = true;
this.config = null; // not used
this.options = options;
this.jspUri = tagFilePath;
this.tripCount = 0;
ctxt = new JspCompilationContext(jspUri, tagInfo, options,
servletContext, this, rctxt,
tagFileJarUrl);
}
public JspCompilationContext getJspEngineContext() {
return ctxt;
}
public void setReload(boolean reload) {
this.reload = reload;
}
public Servlet getServlet()
throws ServletException, IOException, FileNotFoundException
{
// DCL on 'reload' requires that 'reload' be volatile
// (this also forces a read memory barrier, ensuring the
// new servlet object is read consistently)
if (reload) {
synchronized (this) {
// Synchronizing on jsw enables simultaneous loading
// of different pages, but not the same page.
if (reload) {
// This is to maintain the original protocol.
destroy();
final Servlet servlet;
try {
servletClass = ctxt.load();
servlet = (Servlet) servletClass.newInstance();
AnnotationProcessor annotationProcessor = (AnnotationProcessor) config.getServletContext().getAttribute(AnnotationProcessor.class.getName());
if (annotationProcessor != null) {
annotationProcessor.processAnnotations(servlet);
annotationProcessor.postConstruct(servlet);
}
} catch (IllegalAccessException e) {
throw new JasperException(e);
} catch (InstantiationException e) {
throw new JasperException(e);
} catch (Exception e) {
throw new JasperException(e);
}
servlet.init(config);
if (!firstTime) {
ctxt.getRuntimeContext().incrementJspReloadCount();
}
theServlet = servlet;
reload = false;
// Volatile 'reload' forces in order write of 'theServlet' and new servlet object
}
}
}
return theServlet;
}
public ServletContext getServletContext() {
return ctxt.getServletContext();
}
/**
* Sets the compilation exception for this JspServletWrapper.
*
* @param je The compilation exception
*/
public void setCompilationException(JasperException je) {
this.compileException = je;
}
/**
* Sets the last-modified time of the servlet class file associated with
* this JspServletWrapper.
*
* @param lastModified Last-modified time of servlet class
*/
public void setServletClassLastModifiedTime(long lastModified) {
// DCL requires servletClassLastModifiedTime be volatile
// to force read and write barriers on access/set
// (and to get atomic write of long)
if (this.servletClassLastModifiedTime < lastModified) {
synchronized (this) {
if (this.servletClassLastModifiedTime < lastModified) {
this.servletClassLastModifiedTime = lastModified;
reload = true;
}
}
}
}
/**
* Compile (if needed) and load a tag file
*/
public Class loadTagFile() throws JasperException {
try {
if (ctxt.isRemoved()) {
throw new FileNotFoundException(jspUri);
}
if (options.getDevelopment() || firstTime ) {
synchronized (this) {
firstTime = false;
ctxt.compile();
}
} else {
if (compileException != null) {
throw compileException;
}
}
if (reload) {
tagHandlerClass = ctxt.load();
reload = false;
}
} catch (FileNotFoundException ex) {
throw new JasperException(ex);
}
return tagHandlerClass;
}
/**
* Compile and load a prototype for the Tag file. This is needed
* when compiling tag files with circular dependencies. A prototpe
* (skeleton) with no dependencies on other other tag files is
* generated and compiled.
*/
public Class loadTagFilePrototype() throws JasperException {
ctxt.setPrototypeMode(true);
try {
return loadTagFile();
} finally {
ctxt.setPrototypeMode(false);
}
}
/**
* Get a list of files that the current page has source dependency on.
*/
public java.util.List getDependants() {
try {
Object target;
if (isTagFile) {
if (reload) {
tagHandlerClass = ctxt.load();
reload = false;
}
target = tagHandlerClass.newInstance();
} else {
target = getServlet();
}
if (target != null && target instanceof JspSourceDependent) {
return ((java.util.List) ((JspSourceDependent) target).getDependants());
}
} catch (Throwable ex) {
}
return null;
}
public boolean isTagFile() {
return this.isTagFile;
}
public int incTripCount() {
return tripCount++;
}
public int decTripCount() {
return tripCount--;
}
public void service(HttpServletRequest request,
HttpServletResponse response,
boolean precompile)
throws ServletException, IOException, FileNotFoundException {
Servlet servlet;
try {
if (ctxt.isRemoved()) {
throw new FileNotFoundException(jspUri);
}
if ((available > 0L) && (available < Long.MAX_VALUE)) {
if (available > System.currentTimeMillis()) {
response.setDateHeader("Retry-After", available);
response.sendError
(HttpServletResponse.SC_SERVICE_UNAVAILABLE,
Localizer.getMessage("jsp.error.unavailable"));
return;
} else {
// Wait period has expired. Reset.
available = 0;
}
}
/*
* (1) Compile
*/
if (options.getDevelopment() || firstTime ) {
synchronized (this) {
firstTime = false;
// The following sets reload to true, if necessary
ctxt.compile();
}
} else {
if (compileException != null) {
// Throw cached compilation exception
throw compileException;
}
}
/*
* (2) (Re)load servlet class file
*/
servlet = getServlet();
// If a page is to be precompiled only, return.
if (precompile) {
return;
}
} catch (ServletException ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (FileNotFoundException fnfe) {
// File has been removed. Let caller handle this.
throw fnfe;
} catch (IOException ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (IllegalStateException ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (Exception ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw new JasperException(ex);
}
}
try {
/*
* (3) Service request
*/
if (servlet instanceof SingleThreadModel) {
// sync on the wrapper so that the freshness
// of the page is determined right before servicing
synchronized (this) {
servlet.service(request, response);
}
} else {
servlet.service(request, response);
}
} catch (UnavailableException ex) {
String includeRequestUri = (String)
request.getAttribute("javax.servlet.include.request_uri");
if (includeRequestUri != null) {
// This file was included. Throw an exception as
// a response.sendError() will be ignored by the
// servlet engine.
throw ex;
} else {
int unavailableSeconds = ex.getUnavailableSeconds();
if (unavailableSeconds <= 0) {
unavailableSeconds = 60; // Arbitrary default
}
available = System.currentTimeMillis() +
(unavailableSeconds * 1000L);
response.sendError
(HttpServletResponse.SC_SERVICE_UNAVAILABLE,
ex.getMessage());
}
} catch (ServletException ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (IOException ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (IllegalStateException ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw ex;
}
} catch (Exception ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
} else {
throw new JasperException(ex);
}
}
}
public void destroy() {
if (theServlet != null) {
try {
theServlet.destroy();
} catch (Throwable t) {
log.error(Localizer.getMessage("jsp.error.servlet.destroy.failed"), t);
}
AnnotationProcessor annotationProcessor = (AnnotationProcessor) config.getServletContext().getAttribute(AnnotationProcessor.class.getName());
if (annotationProcessor != null) {
try {
annotationProcessor.preDestroy(theServlet);
} catch (Exception e) {
// Log any exception, since it can't be passed along
log.error(Localizer.getMessage("jsp.error.file.not.found",
e.getMessage()), e);
}
}
}
}
/**
* @return Returns the lastModificationTest.
*/
public long getLastModificationTest() {
return lastModificationTest;
}
/**
* @param lastModificationTest The lastModificationTest to set.
*/
public void setLastModificationTest(long lastModificationTest) {
this.lastModificationTest = lastModificationTest;
}
/**
* <p>Attempts to construct a JasperException that contains helpful information
* about what went wrong. Uses the JSP compiler system to translate the line
* number in the generated servlet that originated the exception to a line
* number in the JSP. Then constructs an exception containing that
* information, and a snippet of the JSP to help debugging.
* Please see http://bz.apache.org/bugzilla/show_bug.cgi?id=37062 and
* http://www.tfenne.com/jasper/ for more details.
*</p>
*
* @param ex the exception that was the cause of the problem.
* @return a JasperException with more detailed information
*/
protected JasperException handleJspException(Exception ex) {
try {
Throwable realException = ex;
if (ex instanceof ServletException) {
realException = ((ServletException) ex).getRootCause();
}
// First identify the stack frame in the trace that represents the JSP
StackTraceElement[] frames = realException.getStackTrace();
StackTraceElement jspFrame = null;
for (int i=0; i<frames.length; ++i) {
if ( frames[i].getClassName().equals(this.getServlet().getClass().getName()) ) {
jspFrame = frames[i];
break;
}
}
if (jspFrame == null ||
this.ctxt.getCompiler().getPageNodes() == null) {
// If we couldn't find a frame in the stack trace corresponding
// to the generated servlet class or we don't have a copy of the
// parsed JSP to hand, we can't really add anything
return new JasperException(ex);
}
else {
int javaLineNumber = jspFrame.getLineNumber();
JavacErrorDetail detail = ErrorDispatcher.createJavacError(
jspFrame.getMethodName(),
this.ctxt.getCompiler().getPageNodes(),
null,
javaLineNumber,
ctxt);
// If the line number is less than one we couldn't find out
// where in the JSP things went wrong
int jspLineNumber = detail.getJspBeginLineNumber();
if (jspLineNumber < 1) {
throw new JasperException(ex);
}
if (options.getDisplaySourceFragment()) {
return new JasperException(Localizer.getMessage
("jsp.exception", detail.getJspFileName(),
"" + jspLineNumber) +
"\n\n" + detail.getJspExtract() +
"\n\nStacktrace:", ex);
} else {
return new JasperException(Localizer.getMessage
("jsp.exception", detail.getJspFileName(),
"" + jspLineNumber), ex);
}
}
} catch (Exception je) {
// If anything goes wrong, just revert to the original behaviour
if (ex instanceof JasperException) {
return (JasperException) ex;
} else {
return new JasperException(ex);
}
}
}
}