JspServletWrapper.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.servlet;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.RequestDispatcher;
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.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.Options;
import org.apache.jasper.compiler.JavacErrorDetail;
import org.apache.jasper.compiler.JspRuntimeContext;
import org.apache.jasper.compiler.Localizer;
import org.apache.jasper.compiler.SmapInput;
import org.apache.jasper.compiler.SmapStratum;
import org.apache.jasper.runtime.ExceptionUtils;
import org.apache.jasper.runtime.InstanceManagerFactory;
import org.apache.jasper.runtime.JspSourceDependent;
import org.apache.jasper.util.FastRemovalDequeue;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.InstanceManager;
import org.apache.tomcat.Jar;
/**
* 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
*/
@SuppressWarnings("deprecation") // Have to support SingleThreadModel
public class JspServletWrapper {
private static final Map<String,Long> ALWAYS_OUTDATED_DEPENDENCIES =
new HashMap<>();
static {
// If this is missing,
ALWAYS_OUTDATED_DEPENDENCIES.put("/WEB-INF/web.xml", Long.valueOf(-1));
}
// Logger
private final Log log = LogFactory.getLog(JspServletWrapper.class); // must not be static
private volatile Servlet theServlet;
private final String jspUri;
private volatile Class<?> tagHandlerClass;
private final JspCompilationContext ctxt;
private long available = 0L;
private final ServletConfig config;
private final Options options;
/*
* The servlet / tag file needs a compilation check on first access. Use a
* separate flag (rather then theServlet == null / tagHandlerClass == null
* as it avoids the potentially expensive isOutDated() calls in
* ctxt.compile() if there are multiple concurrent requests for the servlet
* / tag before the class has been loaded.
*/
private volatile boolean mustCompile = true;
/* Whether the servlet/tag file needs reloading on next access */
private volatile boolean reload = true;
private final boolean isTagFile;
private int tripCount;
private JasperException compileException;
/* Timestamp of last time servlet resource was modified */
private volatile long servletClassLastModifiedTime;
private long lastModificationTest = 0L;
private long lastUsageTime = System.currentTimeMillis();
private FastRemovalDequeue<JspServletWrapper>.Entry unloadHandle;
private final boolean unloadAllowed;
private final boolean unloadByCount;
private final boolean unloadByIdle;
/*
* JspServletWrapper for JSP pages.
*/
public JspServletWrapper(ServletConfig config, Options options,
String jspUri, JspRuntimeContext rctxt) {
this.isTagFile = false;
this.config = config;
this.options = options;
this.jspUri = jspUri;
unloadByCount = options.getMaxLoadedJsps() > 0 ? true : false;
unloadByIdle = options.getJspIdleTimeout() > 0 ? true : false;
unloadAllowed = unloadByCount || unloadByIdle ? true : false;
ctxt = new JspCompilationContext(jspUri, options,
config.getServletContext(),
this, rctxt);
}
/*
* JspServletWrapper for tag files.
*/
public JspServletWrapper(ServletContext servletContext,
Options options,
String tagFilePath,
TagInfo tagInfo,
JspRuntimeContext rctxt,
Jar tagJar) {
this.isTagFile = true;
this.config = null; // not used
this.options = options;
this.jspUri = tagFilePath;
this.tripCount = 0;
unloadByCount = options.getMaxLoadedJsps() > 0 ? true : false;
unloadByIdle = options.getJspIdleTimeout() > 0 ? true : false;
unloadAllowed = unloadByCount || unloadByIdle ? true : false;
ctxt = new JspCompilationContext(jspUri, tagInfo, options,
servletContext, this, rctxt,
tagJar);
}
public JspCompilationContext getJspEngineContext() {
return ctxt;
}
public void setReload(boolean reload) {
this.reload = reload;
}
public boolean getReload() {
return reload;
}
private boolean getReloadInternal() {
return reload && !ctxt.getRuntimeContext().isCompileCheckInProgress();
}
public Servlet getServlet() throws ServletException {
/*
* DCL on 'reload' requires that 'reload' be volatile
* (this also forces a read memory barrier, ensuring the new servlet
* object is read consistently).
*
* When running in non development mode with a checkInterval it is
* possible (see BZ 62603) for a race condition to cause failures
* if a Servlet or tag is reloaded while a compile check is running
*/
if (getReloadInternal() || theServlet == null) {
synchronized (this) {
// Synchronizing on jsw enables simultaneous loading
// of different pages, but not the same page.
if (getReloadInternal() || theServlet == null) {
// This is to maintain the original protocol.
destroy();
final Servlet servlet;
try {
InstanceManager instanceManager = InstanceManagerFactory.getInstanceManager(config);
servlet = (Servlet) instanceManager.newInstance(ctxt.getFQCN(), ctxt.getJspLoader());
} catch (Exception e) {
Throwable t = ExceptionUtils
.unwrapInvocationTargetException(e);
ExceptionUtils.handleThrowable(t);
throw new JasperException(t);
}
servlet.init(config);
if (theServlet != null) {
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;
// Really need to unload the old class but can't do that. Do
// the next best thing which is throw away the JspLoader so
// a new loader will be created which will load the new
// class.
// TODO Are there inefficiencies between reload and the
// isOutDated() check?
ctxt.clearJspLoader();
}
}
}
}
/**
* Compile (if needed) and load a tag file.
* @return the loaded class
* @throws JasperException Error compiling or loading tag file
*/
public Class<?> loadTagFile() throws JasperException {
try {
if (ctxt.isRemoved()) {
throw new FileNotFoundException(jspUri);
}
if (options.getDevelopment() || mustCompile) {
synchronized (this) {
if (options.getDevelopment() || mustCompile) {
ctxt.compile();
mustCompile = false;
}
}
} else {
if (compileException != null) {
throw compileException;
}
}
if (getReloadInternal() || tagHandlerClass == null) {
synchronized (this) {
if (getReloadInternal() || tagHandlerClass == null) {
tagHandlerClass = ctxt.load();
// Volatile 'reload' forces in order write of 'tagHandlerClass'
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 prototype
* (skeleton) with no dependencies on other other tag files is
* generated and compiled.
* @return the loaded class
* @throws JasperException Error compiling or loading tag file
*/
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.
* @return the map of dependent resources
*/
public Map<String,Long> getDependants() {
try {
Object target;
if (isTagFile) {
if (reload) {
synchronized (this) {
if (reload) {
tagHandlerClass = ctxt.load();
reload = false;
}
}
}
target = tagHandlerClass.getConstructor().newInstance();
} else {
target = getServlet();
}
if (target instanceof JspSourceDependent) {
return ((JspSourceDependent) target).getDependants();
}
} catch (AbstractMethodError ame) {
// Almost certainly a pre Tomcat 7.0.17 compiled JSP using the old
// version of the interface. Force a re-compile.
return ALWAYS_OUTDATED_DEPENDENCIES;
} catch (Throwable ex) {
ExceptionUtils.handleThrowable(ex);
}
return null;
}
public boolean isTagFile() {
return this.isTagFile;
}
public int incTripCount() {
return tripCount++;
}
public int decTripCount() {
return tripCount--;
}
public String getJspUri() {
return jspUri;
}
public FastRemovalDequeue<JspServletWrapper>.Entry getUnloadHandle() {
return unloadHandle;
}
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;
}
// Wait period has expired. Reset.
available = 0;
}
/*
* (1) Compile
*/
if (options.getDevelopment() || mustCompile) {
synchronized (this) {
if (options.getDevelopment() || mustCompile) {
// The following sets reload to true, if necessary
ctxt.compile();
mustCompile = false;
}
}
} 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 (FileNotFoundException fnfe) {
// File has been removed. Let caller handle this.
throw fnfe;
} catch (ServletException | IOException | IllegalStateException ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
}
throw ex;
} catch (Exception ex) {
if (options.getDevelopment()) {
throw handleJspException(ex);
}
throw new JasperException(ex);
}
try {
/*
* (3) Handle limitation of number of loaded Jsps
*/
if (unloadAllowed) {
synchronized(this) {
if (unloadByCount) {
if (unloadHandle == null) {
unloadHandle = ctxt.getRuntimeContext().push(this);
} else if (lastUsageTime < ctxt.getRuntimeContext().getLastJspQueueUpdate()) {
ctxt.getRuntimeContext().makeYoungest(unloadHandle);
lastUsageTime = System.currentTimeMillis();
}
} else {
if (lastUsageTime < ctxt.getRuntimeContext().getLastJspQueueUpdate()) {
lastUsageTime = System.currentTimeMillis();
}
}
}
}
/*
* (4) 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(RequestDispatcher.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;
}
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 | IllegalStateException ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
}
throw ex;
} catch (IOException ex) {
if (options.getDevelopment()) {
throw new IOException(handleJspException(ex).getMessage(), ex);
}
throw ex;
} catch (Exception ex) {
if(options.getDevelopment()) {
throw handleJspException(ex);
}
throw new JasperException(ex);
}
}
public void destroy() {
if (theServlet != null) {
try {
theServlet.destroy();
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
log.error(Localizer.getMessage("jsp.error.servlet.destroy.failed"), t);
}
InstanceManager instanceManager = InstanceManagerFactory.getInstanceManager(config);
try {
instanceManager.destroyInstance(theServlet);
} catch (Exception e) {
Throwable t = ExceptionUtils.unwrapInvocationTargetException(e);
ExceptionUtils.handleThrowable(t);
// Log any exception, since it can't be passed along
log.error(Localizer.getMessage("jsp.error.file.not.found",
e.getMessage()), t);
}
}
}
/**
* @return Returns the lastModificationTest.
*/
public long getLastModificationTest() {
return lastModificationTest;
}
/**
* @param lastModificationTest The lastModificationTest to set.
*/
public void setLastModificationTest(long lastModificationTest) {
this.lastModificationTest = lastModificationTest;
}
/**
* @return the lastUsageTime.
*/
public long getLastUsageTime() {
return lastUsageTime;
}
/**
* <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 https://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();
}
// Find the first stack frame that represents code generated by
// Jasper
StackTraceElement[] frames = realException.getStackTrace();
StackTraceElement jspFrame = null;
String servletPackageName = ctxt.getBasePackageName();
for (StackTraceElement frame : frames) {
if (frame.getClassName().startsWith(servletPackageName)) {
jspFrame = frame;
break;
}
}
SmapStratum smap = null;
if (jspFrame != null) {
smap = ctxt.getCompiler().getSmap(jspFrame.getClassName());
}
if (smap == 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
// smap to hand, we can't really add anything
return new JasperException(ex);
}
@SuppressWarnings("null")
int javaLineNumber = jspFrame.getLineNumber();
SmapInput source = smap.getInputLineNumber(javaLineNumber);
// If the line number is less than one we couldn't find out
// where in the JSP things went wrong
if (source.getLineNumber() < 1) {
throw new JasperException(ex);
}
JavacErrorDetail detail = new JavacErrorDetail(jspFrame.getMethodName(), javaLineNumber,
source.getFileName(), source.getLineNumber(), null, ctxt);
if (options.getDisplaySourceFragment()) {
return new JasperException(Localizer.getMessage
("jsp.exception", detail.getJspFileName(),
"" + source.getLineNumber()) + System.lineSeparator() +
System.lineSeparator() + detail.getJspExtract() +
System.lineSeparator() + System.lineSeparator() +
"Stacktrace:", ex);
}
return new JasperException(Localizer.getMessage
("jsp.exception", detail.getJspFileName(),
"" + source.getLineNumber()), ex);
} catch (Exception je) {
// If anything goes wrong, just revert to the original behaviour
if (ex instanceof JasperException) {
return (JasperException) ex;
}
return new JasperException(ex);
}
}
}