/*
* 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.
*/
// Modified by Google.
package org.apache.catalina.loader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilePermission;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessControlException;
import java.security.AccessController;
import java.security.CodeSource;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.Policy;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Vector;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.jar.Attributes.Name;
import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.util.StringManager;
import org.apache.naming.JndiPermission;
import org.apache.naming.resources.Resource;
import org.apache.naming.resources.ResourceAttributes;
import org.apache.tomcat.util.compat.JdkCompat;
/**
* Specialized web application class loader.
* <p>
* This class loader is a full reimplementation of the
* <code>URLClassLoader</code> from the JDK. It is desinged to be fully
* compatible with a normal <code>URLClassLoader</code>, although its internal
* behavior may be completely different.
* <p>
* <strong>IMPLEMENTATION NOTE</strong> - This class loader faithfully follows
* the delegation model recommended in the specification. The system class
* loader will be queried first, then the local repositories, and only then
* delegation to the parent class loader will occur. This allows the web
* application to override any shared class except the classes from J2SE.
* Special handling is provided from the JAXP XML parser interfaces, the JNDI
* interfaces, and the classes from the servlet API, which are never loaded
* from the webapp repository.
* <p>
* <strong>IMPLEMENTATION NOTE</strong> - Due to limitations in Jasper
* compilation technology, any repository which contains classes from
* the servlet API will be ignored by the class loader.
* <p>
* <strong>IMPLEMENTATION NOTE</strong> - The class loader generates source
* URLs which include the full JAR URL when a class is loaded from a JAR file,
* which allows setting security permission at the class level, even when a
* class is contained inside a JAR.
* <p>
* <strong>IMPLEMENTATION NOTE</strong> - Local repositories are searched in
* the order they are added via the initial constructor and/or any subsequent
* calls to <code>addRepository()</code> or <code>addJar()</code>.
* <p>
* <strong>IMPLEMENTATION NOTE</strong> - No check for sealing violations or
* security is made unless a security manager is present.
*
* @author Remy Maucherat
* @author Craig R. McClanahan
* @version $Revision: 1.34 $ $Date: 2004/05/26 15:47:40 $
*/
public class WebappClassLoader
extends URLClassLoader
implements Reloader, Lifecycle
{
private static org.apache.commons.logging.Log log=
org.apache.commons.logging.LogFactory.getLog( WebappClassLoader.class );
protected class PrivilegedFindResource
implements PrivilegedAction {
private File file;
private String path;
PrivilegedFindResource(File file, String path) {
this.file = file;
this.path = path;
}
public Object run() {
return findResourceInternal(file, path);
}
}
// ------------------------------------------------------- Static Variables
/**
* The set of trigger classes that will cause a proposed repository not
* to be added if this class is visible to the class loader that loaded
* this factory class. Typically, trigger classes will be listed for
* components that have been integrated into the JDK for later versions,
* but where the corresponding JAR files are required to run on
* earlier versions.
*/
private static final String[] triggers = {
"javax.servlet.Servlet" // Servlet API
};
/**
* Jdk Compatibility Support.
*/
private static JdkCompat jdkCompat = JdkCompat.getJdkCompat();
/**
* Set of package names which are not allowed to be loaded from a webapp
* class loader without delegating first.
*/
private static final String[] packageTriggers = {
"javax", // Java extensions
"org.xml.sax", // SAX 1 & 2
"org.w3c.dom", // DOM 1 & 2
"org.apache.xerces", // Xerces 1 & 2
"org.apache.xalan" // Xalan
};
/**
* The string manager for this package.
*/
protected static final StringManager sm =
StringManager.getManager(Constants.Package);
// ----------------------------------------------------------- Constructors
/**
* Construct a new ClassLoader with no defined repositories and no
* parent ClassLoader.
*/
public WebappClassLoader() {
super(new URL[0]);
this.parent = getParent();
system = getSystemClassLoader();
securityManager = System.getSecurityManager();
if (securityManager != null) {
refreshPolicy();
}
}
/**
* Construct a new ClassLoader with no defined repositories and no
* parent ClassLoader.
*/
public WebappClassLoader(ClassLoader parent) {
super(new URL[0], parent);
this.parent = getParent();
system = getSystemClassLoader();
securityManager = System.getSecurityManager();
if (securityManager != null) {
refreshPolicy();
}
}
// ----------------------------------------------------- Instance Variables
/**
* Associated directory context giving access to the resources in this
* webapp.
*/
protected DirContext resources = null;
/**
* The cache of ResourceEntry for classes and resources we have loaded,
* keyed by resource name.
*/
protected HashMap resourceEntries = new HashMap();
/**
* The list of not found resources.
*/
protected HashMap notFoundResources = new HashMap();
/**
* The debugging detail level of this component.
*/
protected int debug = 0;
/**
* Should this class loader delegate to the parent class loader
* <strong>before</strong> searching its own repositories (i.e. the
* usual Java2 delegation model)? If set to <code>false</code>,
* this class loader will search its own repositories first, and
* delegate to the parent only if the class or resource is not
* found locally.
*/
protected boolean delegate = false;
/**
* Last time a JAR was accessed.
*/
protected long lastJarAccessed = 0L;
/**
* The list of local repositories, in the order they should be searched
* for locally loaded classes or resources.
*/
protected String[] repositories = new String[0];
/**
* Repositories URLs, used to cache the result of getURLs.
*/
protected URL[] repositoryURLs = null;
/**
* Repositories translated as path in the work directory (for Jasper
* originally), but which is used to generate fake URLs should getURLs be
* called.
*/
protected File[] files = new File[0];
/**
* The list of JARs, in the order they should be searched
* for locally loaded classes or resources.
*/
protected JarFile[] jarFiles = new JarFile[0];
/**
* The list of JARs, in the order they should be searched
* for locally loaded classes or resources.
*/
protected File[] jarRealFiles = new File[0];
/**
* The path which will be monitored for added Jar files.
*/
protected String jarPath = null;
/**
* The list of JARs, in the order they should be searched
* for locally loaded classes or resources.
*/
protected String[] jarNames = new String[0];
/**
* The list of JARs last modified dates, in the order they should be
* searched for locally loaded classes or resources.
*/
protected long[] lastModifiedDates = new long[0];
/**
* The list of resources which should be checked when checking for
* modifications.
*/
protected String[] paths = new String[0];
/**
* A list of read File and Jndi Permission's required if this loader
* is for a web application context.
*/
private ArrayList permissionList = new ArrayList();
/**
* Path where resources loaded from JARs will be extracted.
*/
private File loaderDir = null;
/**
* The PermissionCollection for each CodeSource for a web
* application context.
*/
private HashMap loaderPC = new HashMap();
/**
* Instance of the SecurityManager installed.
*/
private SecurityManager securityManager = null;
/**
* The parent class loader.
*/
private ClassLoader parent = null;
/**
* The system class loader.
*/
private ClassLoader system = null;
/**
* Has this component been started?
*/
protected boolean started = false;
/**
* Has external repositories.
*/
protected boolean hasExternalRepositories = false;
/**
* All permission.
*/
private Permission allPermission = new java.security.AllPermission();
// ------------------------------------------------------------- Properties
/**
* Get associated resources.
*/
public DirContext getResources() {
return this.resources;
}
/**
* Set associated resources.
*/
public void setResources(DirContext resources) {
this.resources = resources;
}
/**
* Return the debugging detail level for this component.
*/
public int getDebug() {
return (this.debug);
}
/**
* Set the debugging detail level for this component.
*
* @param debug The new debugging detail level
*/
public void setDebug(int debug) {
this.debug = debug;
}
/**
* Return the "delegate first" flag for this class loader.
*/
public boolean getDelegate() {
return (this.delegate);
}
/**
* Set the "delegate first" flag for this class loader.
*
* @param delegate The new "delegate first" flag
*/
public void setDelegate(boolean delegate) {
this.delegate = delegate;
}
/**
* If there is a Java SecurityManager create a read FilePermission
* or JndiPermission for the file directory path.
*
* @param path file directory path
*/
public void addPermission(String path) {
if (path == null) {
return;
}
if (securityManager != null) {
Permission permission = null;
if( path.startsWith("jndi:") || path.startsWith("jar:jndi:") ) {
if (!path.endsWith("/")) {
path = path + "/";
}
permission = new JndiPermission(path + "*");
addPermission(permission);
} else {
if (!path.endsWith(File.separator)) {
permission = new FilePermission(path, "read");
addPermission(permission);
path = path + File.separator;
}
permission = new FilePermission(path + "-", "read");
addPermission(permission);
}
}
}
/**
* If there is a Java SecurityManager create a read FilePermission
* or JndiPermission for URL.
*
* @param url URL for a file or directory on local system
*/
public void addPermission(URL url) {
if (url != null) {
addPermission(url.toString());
}
}
/**
* If there is a Java SecurityManager create a Permission.
*
* @param url URL for a file or directory on local system
*/
public void addPermission(Permission permission) {
if ((securityManager != null) && (permission != null)) {
permissionList.add(permission);
}
}
/**
* Return the JAR path.
*/
public String getJarPath() {
return this.jarPath;
}
/**
* Change the Jar path.
*/
public void setJarPath(String jarPath) {
this.jarPath = jarPath;
}
/**
* Change the work directory.
*/
public void setWorkDir(File workDir) {
this.loaderDir = new File(workDir, "loader");
}
// ------------------------------------------------------- Reloader Methods
/**
* Add a new repository to the set of places this ClassLoader can look for
* classes to be loaded.
*
* @param repository Name of a source of classes to be loaded, such as a
* directory pathname, a JAR file pathname, or a ZIP file pathname
*
* @exception IllegalArgumentException if the specified repository is
* invalid or does not exist
*/
public void addRepository(String repository) {
// Ignore any of the standard repositories, as they are set up using
// either addJar or addRepository
if (repository.startsWith("/WEB-INF/lib")
|| repository.startsWith("/WEB-INF/classes"))
return;
// Add this repository to our underlying class loader
try {
URL url = new URL(repository);
super.addURL(url);
hasExternalRepositories = true;
repositoryURLs = null;
} catch (MalformedURLException e) {
IllegalArgumentException iae = new IllegalArgumentException
("Invalid repository: " + repository);
jdkCompat.chainException(iae, e);
throw iae;
}
}
/**
* Add a new repository to the set of places this ClassLoader can look for
* classes to be loaded.
*
* @param repository Name of a source of classes to be loaded, such as a
* directory pathname, a JAR file pathname, or a ZIP file pathname
*
* @exception IllegalArgumentException if the specified repository is
* invalid or does not exist
*/
synchronized void addRepository(String repository, File file) {
// Note : There should be only one (of course), but I think we should
// keep this a bit generic
if (repository == null)
return;
if (log.isDebugEnabled())
log.debug("addRepository(" + repository + ")");
int i;
// Add this repository to our internal list
String[] result = new String[repositories.length + 1];
for (i = 0; i < repositories.length; i++) {
result[i] = repositories[i];
}
result[repositories.length] = repository;
repositories = result;
// Add the file to the list
File[] result2 = new File[files.length + 1];
for (i = 0; i < files.length; i++) {
result2[i] = files[i];
}
result2[files.length] = file;
files = result2;
}
synchronized void addJar(String jar, JarFile jarFile, File file)
throws IOException {
if (jar == null)
return;
if (jarFile == null)
return;
if (file == null)
return;
if (log.isDebugEnabled())
log.debug("addJar(" + jar + ")");
int i;
if ((jarPath != null) && (jar.startsWith(jarPath))) {
String jarName = jar.substring(jarPath.length());
while (jarName.startsWith("/"))
jarName = jarName.substring(1);
String[] result = new String[jarNames.length + 1];
for (i = 0; i < jarNames.length; i++) {
result[i] = jarNames[i];
}
result[jarNames.length] = jarName;
jarNames = result;
}
try {
// Register the JAR for tracking
long lastModified =
((ResourceAttributes) resources.getAttributes(jar))
.getLastModified();
String[] result = new String[paths.length + 1];
for (i = 0; i < paths.length; i++) {
result[i] = paths[i];
}
result[paths.length] = jar;
paths = result;
long[] result3 = new long[lastModifiedDates.length + 1];
for (i = 0; i < lastModifiedDates.length; i++) {
result3[i] = lastModifiedDates[i];
}
result3[lastModifiedDates.length] = lastModified;
lastModifiedDates = result3;
} catch (NamingException e) {
// Ignore
}
// If the JAR currently contains invalid classes, don't actually use it
// for classloading
if (!validateJarFile(file))
return;
JarFile[] result2 = new JarFile[jarFiles.length + 1];
for (i = 0; i < jarFiles.length; i++) {
result2[i] = jarFiles[i];
}
result2[jarFiles.length] = jarFile;
jarFiles = result2;
// Add the file to the list
File[] result4 = new File[jarRealFiles.length + 1];
for (i = 0; i < jarRealFiles.length; i++) {
result4[i] = jarRealFiles[i];
}
result4[jarRealFiles.length] = file;
jarRealFiles = result4;
}
/**
* Return a String array of the current repositories for this class
* loader. If there are no repositories, a zero-length array is
* returned.For security reason, returns a clone of the Array (since
* String are immutable).
*/
public String[] findRepositories() {
return ((String[])repositories.clone());
}
/**
* Have one or more classes or resources been modified so that a reload
* is appropriate?
*/
public boolean modified() {
if (log.isDebugEnabled())
log.debug("modified()");
// Checking for modified loaded resources
int length = paths.length;
// A rare race condition can occur in the updates of the two arrays
// It's totally ok if the latest class added is not checked (it will
// be checked the next time
int length2 = lastModifiedDates.length;
if (length > length2)
length = length2;
for (int i = 0; i < length; i++) {
try {
long lastModified =
((ResourceAttributes) resources.getAttributes(paths[i]))
.getLastModified();
if (lastModified != lastModifiedDates[i]) {
if( log.isDebugEnabled() )
log.debug(" Resource '" + paths[i]
+ "' was modified; Date is now: "
+ new java.util.Date(lastModified) + " Was: "
+ new java.util.Date(lastModifiedDates[i]));
return (true);
}
} catch (NamingException e) {
log.error(" Resource '" + paths[i] + "' is missing");
return (true);
}
}
length = jarNames.length;
// Check if JARs have been added or removed
if (getJarPath() != null) {
try {
NamingEnumeration enum_ = resources.listBindings(getJarPath());
int i = 0;
while (enum_.hasMoreElements() && (i < length)) {
NameClassPair ncPair = (NameClassPair) enum_.nextElement();
String name = ncPair.getName();
// Ignore non JARs present in the lib folder
if (!name.endsWith(".jar"))
continue;
if (!name.equals(jarNames[i])) {
// Missing JAR
log.info(" Additional JARs have been added : '"
+ name + "'");
return (true);
}
i++;
}
if (enum_.hasMoreElements()) {
while (enum_.hasMoreElements()) {
NameClassPair ncPair =
(NameClassPair) enum_.nextElement();
String name = ncPair.getName();
// Additional non-JAR files are allowed
if (name.endsWith(".jar")) {
// There was more JARs
log.info(" Additional JARs have been added");
return (true);
}
}
} else if (i < jarNames.length) {
// There was less JARs
log.info(" Additional JARs have been added");
return (true);
}
} catch (NamingException e) {
if (log.isDebugEnabled())
log.debug(" Failed tracking modifications of '"
+ getJarPath() + "'");
} catch (ClassCastException e) {
log.error(" Failed tracking modifications of '"
+ getJarPath() + "' : " + e.getMessage());
}
}
// No classes have been modified
return (false);
}
/**
* Render a String representation of this object.
*/
public String toString() {
StringBuffer sb = new StringBuffer("WebappClassLoader\r\n");
sb.append(" delegate: ");
sb.append(delegate);
sb.append("\r\n");
sb.append(" repositories:\r\n");
if (repositories != null) {
for (int i = 0; i < repositories.length; i++) {
sb.append(" ");
sb.append(repositories[i]);
sb.append("\r\n");
}
}
if (this.parent != null) {
sb.append("----------> Parent Classloader:\r\n");
sb.append(this.parent.toString());
sb.append("\r\n");
}
return (sb.toString());
}
// ---------------------------------------------------- ClassLoader Methods
/**
* Add the specified URL to the classloader.
*/
protected void addURL(URL url) {
super.addURL(url);
hasExternalRepositories = true;
repositoryURLs = null;
}
/**
* Find the specified class in our local repositories, if possible. If
* not found, throw <code>ClassNotFoundException</code>.
*
* @param name Name of the class to be loaded
*
* @exception ClassNotFoundException if the class was not found
*/
public Class findClass(String name) throws ClassNotFoundException {
if (log.isDebugEnabled())
log.debug(" findClass(" + name + ")");
// (1) Permission to define this class when using a SecurityManager
if (securityManager != null) {
int i = name.lastIndexOf('.');
if (i >= 0) {
try {
if (log.isTraceEnabled())
log.trace(" securityManager.checkPackageDefinition");
securityManager.checkPackageDefinition(name.substring(0,i));
} catch (Exception se) {
if (log.isTraceEnabled())
log.trace(" -->Exception-->ClassNotFoundException", se);
throw new ClassNotFoundException(name, se);
}
}
}
// Ask our superclass to locate this class, if possible
// (throws ClassNotFoundException if it is not found)
Class clazz = null;
try {
if (log.isTraceEnabled())
log.trace(" findClassInternal(" + name + ")");
try {
clazz = findClassInternal(name);
} catch(ClassNotFoundException cnfe) {
if (!hasExternalRepositories) {
throw cnfe;
}
} catch(AccessControlException ace) {
throw new ClassNotFoundException(name, ace);
} catch (RuntimeException e) {
if (log.isTraceEnabled())
log.trace(" -->RuntimeException Rethrown", e);
throw e;
}
if ((clazz == null) && hasExternalRepositories) {
try {
clazz = super.findClass(name);
} catch(AccessControlException ace) {
throw new ClassNotFoundException(name, ace);
} catch (RuntimeException e) {
if (log.isTraceEnabled())
log.trace(" -->RuntimeException Rethrown", e);
throw e;
}
}
if (clazz == null) {
if (log.isDebugEnabled())
log.debug(" --> Returning ClassNotFoundException");
throw new ClassNotFoundException(name);
}
} catch (ClassNotFoundException e) {
if (log.isTraceEnabled())
log.trace(" --> Passing on ClassNotFoundException");
throw e;
}
// Return the class we have located
if (log.isTraceEnabled())
log.debug(" Returning class " + clazz);
if ((log.isTraceEnabled()) && (clazz != null))
log.debug(" Loaded by " + clazz.getClassLoader());
return (clazz);
}
/**
* Find the specified resource in our local repository, and return a
* <code>URL</code> refering to it, or <code>null</code> if this resource
* cannot be found.
*
* @param name Name of the resource to be found
*/
public URL findResource(final String name) {
if (log.isDebugEnabled())
log.debug(" findResource(" + name + ")");
URL url = null;
ResourceEntry entry = (ResourceEntry) resourceEntries.get(name);
if (entry == null) {
entry = findResourceInternal(name, name);
}
if (entry != null) {
url = entry.source;
}
if ((url == null) && hasExternalRepositories)
url = super.findResource(name);
if (log.isDebugEnabled()) {
if (url != null)
log.debug(" --> Returning '" + url.toString() + "'");
else
log.debug(" --> Resource not found, returning null");
}
return (url);
}
/**
* Return an enumeration of <code>URLs</code> representing all of the
* resources with the given name. If no resources with this name are
* found, return an empty enumeration.
*
* @param name Name of the resources to be found
*
* @exception IOException if an input/output error occurs
*/
public Enumeration findResources(String name) throws IOException {
if (log.isDebugEnabled())
log.debug(" findResources(" + name + ")");
Vector result = new Vector();
int jarFilesLength = jarFiles.length;
int repositoriesLength = repositories.length;
int i;
// Looking at the repositories
for (i = 0; i < repositoriesLength; i++) {
try {
String fullPath = repositories[i] + name;
resources.lookup(fullPath);
// Note : Not getting an exception here means the resource was
// found
try {
result.addElement(getURI(new File(files[i], name)));
} catch (MalformedURLException e) {
// Ignore
}
} catch (NamingException e) {
}
}
// Looking at the JAR files
synchronized (jarFiles) {
openJARs();
for (i = 0; i < jarFilesLength; i++) {
JarEntry jarEntry = jarFiles[i].getJarEntry(name);
if (jarEntry != null) {
try {
String jarFakeUrl = getURI(jarRealFiles[i]).toString();
jarFakeUrl = "jar:" + jarFakeUrl + "!/" + name;
result.addElement(new URL(jarFakeUrl));
} catch (MalformedURLException e) {
// Ignore
}
}
}
}
// Adding the results of a call to the superclass
if (hasExternalRepositories) {
Enumeration otherResourcePaths = super.findResources(name);
while (otherResourcePaths.hasMoreElements()) {
result.addElement(otherResourcePaths.nextElement());
}
}
return result.elements();
}
/**
* Find the resource with the given name. A resource is some data
* (images, audio, text, etc.) that can be accessed by class code in a
* way that is independent of the location of the code. The name of a
* resource is a "/"-separated path name that identifies the resource.
* If the resource cannot be found, return <code>null</code>.
* <p>
* This method searches according to the following algorithm, returning
* as soon as it finds the appropriate URL. If the resource cannot be
* found, returns <code>null</code>.
* <ul>
* <li>If the <code>delegate</code> property is set to <code>true</code>,
* call the <code>getResource()</code> method of the parent class
* loader, if any.</li>
* <li>Call <code>findResource()</code> to find this resource in our
* locally defined repositories.</li>
* <li>Call the <code>getResource()</code> method of the parent class
* loader, if any.</li>
* </ul>
*
* @param name Name of the resource to return a URL for
*/
public URL getResource(String name) {
if (log.isDebugEnabled())
log.debug("getResource(" + name + ")");
URL url = null;
// (1) Delegate to parent if requested
if (delegate) {
if (log.isDebugEnabled())
log.debug(" Delegating to parent classloader " + parent);
ClassLoader loader = parent;
if (loader == null)
loader = system;
url = loader.getResource(name);
if (url != null) {
if (log.isDebugEnabled())
log.debug(" --> Returning '" + url.toString() + "'");
return (url);
}
}
// (2) Search local repositories
url = findResource(name);
if (url != null) {
// Locating the repository for special handling in the case
// of a JAR
ResourceEntry entry = (ResourceEntry) resourceEntries.get(name);
try {
String repository = entry.codeBase.toString();
if ((repository.endsWith(".jar"))
&& (!(name.endsWith(".class")))) {
// Copy binary content to the work directory if not present
File resourceFile = new File(loaderDir, name);
url = resourceFile.toURL();
}
} catch (Exception e) {
// Ignore
}
if (log.isDebugEnabled())
log.debug(" --> Returning '" + url.toString() + "'");
return (url);
}
// (3) Delegate to parent unconditionally if not already attempted
if( !delegate ) {
ClassLoader loader = parent;
if (loader == null)
loader = system;
url = loader.getResource(name);
if (url != null) {
if (log.isDebugEnabled())
log.debug(" --> Returning '" + url.toString() + "'");
return (url);
}
}
// (4) Resource was not found
if (log.isDebugEnabled())
log.debug(" --> Resource not found, returning null");
return (null);
}
/**
* Find the resource with the given name, and return an input stream
* that can be used for reading it. The search order is as described
* for <code>getResource()</code>, after checking to see if the resource
* data has been previously cached. If the resource cannot be found,
* return <code>null</code>.
*
* @param name Name of the resource to return an input stream for
*/
public InputStream getResourceAsStream(String name) {
if (log.isDebugEnabled())
log.debug("getResourceAsStream(" + name + ")");
InputStream stream = null;
// (0) Check for a cached copy of this resource
stream = findLoadedResource(name);
if (stream != null) {
if (log.isDebugEnabled())
log.debug(" --> Returning stream from cache");
return (stream);
}
// (1) Delegate to parent if requested
if (delegate) {
if (log.isDebugEnabled())
log.debug(" Delegating to parent classloader " + parent);
ClassLoader loader = parent;
if (loader == null)
loader = system;
stream = loader.getResourceAsStream(name);
if (stream != null) {
// FIXME - cache???
if (log.isDebugEnabled())
log.debug(" --> Returning stream from parent");
return (stream);
}
}
// (2) Search local repositories
if (log.isDebugEnabled())
log.debug(" Searching local repositories");
URL url = findResource(name);
if (url != null) {
// FIXME - cache???
if (log.isDebugEnabled())
log.debug(" --> Returning stream from local");
stream = findLoadedResource(name);
try {
if (hasExternalRepositories && (stream == null))
stream = url.openStream();
} catch (IOException e) {
; // Ignore
}
if (stream != null)
return (stream);
}
// (3) Delegate to parent unconditionally
if (!delegate) {
if (log.isDebugEnabled())
log.debug(" Delegating to parent classloader unconditionally " + parent);
ClassLoader loader = parent;
if (loader == null)
loader = system;
stream = loader.getResourceAsStream(name);
if (stream != null) {
// FIXME - cache???
if (log.isDebugEnabled())
log.debug(" --> Returning stream from parent");
return (stream);
}
}
// (4) Resource was not found
if (log.isDebugEnabled())
log.debug(" --> Resource not found, returning null");
return (null);
}
/**
* Load the class with the specified name. This method searches for
* classes in the same manner as <code>loadClass(String, boolean)</code>
* with <code>false</code> as the second argument.
*
* @param name Name of the class to be loaded
*
* @exception ClassNotFoundException if the class was not found
*/
public Class loadClass(String name) throws ClassNotFoundException {
return (loadClass(name, false));
}
/**
* Load the class with the specified name, searching using the following
* algorithm until it finds and returns the class. If the class cannot
* be found, returns <code>ClassNotFoundException</code>.
* <ul>
* <li>Call <code>findLoadedClass(String)</code> to check if the
* class has already been loaded. If it has, the same
* <code>Class</code> object is returned.</li>
* <li>If the <code>delegate</code> property is set to <code>true</code>,
* call the <code>loadClass()</code> method of the parent class
* loader, if any.</li>
* <li>Call <code>findClass()</code> to find this class in our locally
* defined repositories.</li>
* <li>Call the <code>loadClass()</code> method of our parent
* class loader, if any.</li>
* </ul>
* If the class was found using the above steps, and the
* <code>resolve</code> flag is <code>true</code>, this method will then
* call <code>resolveClass(Class)</code> on the resulting Class object.
*
* @param name Name of the class to be loaded
* @param resolve If <code>true</code> then resolve the class
*
* @exception ClassNotFoundException if the class was not found
*/
public Class loadClass(String name, boolean resolve)
throws ClassNotFoundException {
if (log.isDebugEnabled())
log.debug("loadClass(" + name + ", " + resolve + ")");
Class clazz = null;
// Don't load classes if class loader is stopped
if (!started) {
log.info(sm.getString("webappClassLoader.stopped"));
throw new ThreadDeath();
}
// (0) Check our previously loaded local class cache
clazz = findLoadedClass0(name);
if (clazz != null) {
if (log.isDebugEnabled())
log.debug(" Returning class from cache");
if (resolve)
resolveClass(clazz);
return (clazz);
}
// (0.1) Check our previously loaded class cache
clazz = findLoadedClass(name);
if (clazz != null) {
if (log.isDebugEnabled())
log.debug(" Returning class from cache");
if (resolve)
resolveClass(clazz);
return (clazz);
}
// (0.2) Try loading the class with the system class loader, to prevent
// the webapp from overriding J2SE classes
// GOOGLE: use the bootstrap loader, not the system loader; it breaks
// embedding.
try {
// clazz = system.loadClass(name);
clazz = Class.forName(name, false, null);
if (clazz != null) {
if (resolve)
resolveClass(clazz);
return (clazz);
}
} catch (ClassNotFoundException e) {
// Ignore
}
// (0.5) Permission to access this class when using a SecurityManager
if (securityManager != null) {
int i = name.lastIndexOf('.');
if (i >= 0) {
try {
securityManager.checkPackageAccess(name.substring(0,i));
} catch (SecurityException se) {
String error = "Security Violation, attempt to use " +
"Restricted Class: " + name;
log.info(error, se);
throw new ClassNotFoundException(error, se);
}
}
}
boolean delegateLoad = delegate || filter(name);
// (1) Delegate to our parent if requested
if (delegateLoad) {
if (log.isDebugEnabled())
log.debug(" Delegating to parent classloader1 " + parent);
ClassLoader loader = parent;
if (loader == null)
loader = system;
try {
clazz = loader.loadClass(name);
if (clazz != null) {
if (log.isDebugEnabled())
log.debug(" Loading class from parent");
if (resolve)
resolveClass(clazz);
return (clazz);
}
} catch (ClassNotFoundException e) {
;
}
}
// (2) Search local repositories
if (log.isDebugEnabled())
log.debug(" Searching local repositories");
try {
clazz = findClass(name);
if (clazz != null) {
if (log.isDebugEnabled())
log.debug(" Loading class from local repository");
if (resolve)
resolveClass(clazz);
return (clazz);
}
} catch (ClassNotFoundException e) {
;
}
// (3) Delegate to parent unconditionally
if (!delegateLoad) {
if (log.isDebugEnabled())
log.debug(" Delegating to parent classloader at end: " + parent);
ClassLoader loader = parent;
if (loader == null)
loader = system;
try {
clazz = loader.loadClass(name);
if (clazz != null) {
if (log.isDebugEnabled())
log.debug(" Loading class from parent");
if (resolve)
resolveClass(clazz);
return (clazz);
}
} catch (ClassNotFoundException e) {
;
}
}
throw new ClassNotFoundException(name);
}
/**
* Get the Permissions for a CodeSource. If this instance
* of WebappClassLoader is for a web application context,
* add read FilePermission or JndiPermissions for the base
* directory (if unpacked),
* the context URL, and jar file resources.
*
* @param codeSource where the code was loaded from
* @return PermissionCollection for CodeSource
*/
protected PermissionCollection getPermissions(CodeSource codeSource) {
String codeUrl = codeSource.getLocation().toString();
PermissionCollection pc;
if ((pc = (PermissionCollection)loaderPC.get(codeUrl)) == null) {
pc = super.getPermissions(codeSource);
if (pc != null) {
Iterator perms = permissionList.iterator();
while (perms.hasNext()) {
Permission p = (Permission)perms.next();
pc.add(p);
}
loaderPC.put(codeUrl,pc);
}
}
return (pc);
}
/**
* Returns the search path of URLs for loading classes and resources.
* This includes the original list of URLs specified to the constructor,
* along with any URLs subsequently appended by the addURL() method.
* @return the search path of URLs for loading classes and resources.
*/
public URL[] getURLs() {
if (repositoryURLs != null) {
return repositoryURLs;
}
URL[] external = super.getURLs();
int filesLength = files.length;
int jarFilesLength = jarRealFiles.length;
int length = filesLength + jarFilesLength + external.length;
int i;
try {
URL[] urls = new URL[length];
for (i = 0; i < length; i++) {
if (i < filesLength) {
urls[i] = getURL(files[i]);
} else if (i < filesLength + jarFilesLength) {
urls[i] = getURL(jarRealFiles[i - filesLength]);
} else {
urls[i] = external[i - filesLength - jarFilesLength];
}
}
repositoryURLs = urls;
} catch (MalformedURLException e) {
repositoryURLs = new URL[0];
}
return repositoryURLs;
}
// ------------------------------------------------------ Lifecycle Methods
/**
* Add a lifecycle event listener to this component.
*
* @param listener The listener to add
*/
public void addLifecycleListener(LifecycleListener listener) {
}
/**
* Get the lifecycle listeners associated with this lifecycle. If this
* Lifecycle has no listeners registered, a zero-length array is returned.
*/
public LifecycleListener[] findLifecycleListeners() {
return new LifecycleListener[0];
}
/**
* Remove a lifecycle event listener from this component.
*
* @param listener The listener to remove
*/
public void removeLifecycleListener(LifecycleListener listener) {
}
/**
* Start the class loader.
*
* @exception LifecycleException if a lifecycle error occurs
*/
public void start() throws LifecycleException {
started = true;
}
/**
* Stop the class loader.
*
* @exception LifecycleException if a lifecycle error occurs
*/
public void stop() throws LifecycleException {
started = false;
int length = files.length;
for (int i = 0; i < length; i++) {
files[i] = null;
}
length = jarFiles.length;
for (int i = 0; i < length; i++) {
try {
if (jarFiles[i] != null) {
jarFiles[i].close();
}
} catch (IOException e) {
// Ignore
}
jarFiles[i] = null;
}
notFoundResources.clear();
resourceEntries.clear();
resources = null;
repositories = null;
repositoryURLs = null;
files = null;
jarFiles = null;
jarRealFiles = null;
jarPath = null;
jarNames = null;
lastModifiedDates = null;
paths = null;
hasExternalRepositories = false;
parent = null;
permissionList.clear();
loaderPC.clear();
if (loaderDir != null) {
deleteDir(loaderDir);
}
org.apache.commons.logging.LogFactory.release(this);
}
/**
* Used to periodically signal to the classloader to release
* JAR resources.
*/
public void closeJARs(boolean force) {
if (jarFiles.length > 0) {
try {
synchronized (jarFiles) {
if (force || (System.currentTimeMillis()
> (lastJarAccessed + 90000))) {
for (int i = 0; i < jarFiles.length; i++) {
if (jarFiles[i] != null) {
jarFiles[i].close();
jarFiles[i] = null;
}
}
}
}
} catch (IOException e) {
log("Failed to close JAR", e);
}
}
}
// ------------------------------------------------------ Protected Methods
/**
* Used to periodically signal to the classloader to release JAR resources.
*/
protected void openJARs() {
if (started && (jarFiles.length > 0)) {
lastJarAccessed = System.currentTimeMillis();
if (jarFiles[0] == null) {
try {
for (int i = 0; i < jarFiles.length; i++) {
jarFiles[i] = new JarFile(jarRealFiles[i]);
}
} catch (IOException e) {
log("Failed to open JAR", e);
}
}
}
}
/**
* Find specified class in local repositories.
*
* @return the loaded class, or null if the class isn't found
*/
protected Class findClassInternal(String name)
throws ClassNotFoundException {
if (!validate(name))
throw new ClassNotFoundException(name);
String tempPath = name.replace('.', '/');
String classPath = tempPath + ".class";
ResourceEntry entry = null;
entry = findResourceInternal(name, classPath);
if ((entry == null) || (entry.binaryContent == null))
throw new ClassNotFoundException(name);
Class clazz = entry.loadedClass;
if (clazz != null)
return clazz;
// Looking up the package
String packageName = null;
int pos = name.lastIndexOf('.');
if (pos != -1)
packageName = name.substring(0, pos);
Package pkg = null;
if (packageName != null) {
pkg = getPackage(packageName);
// Define the package (if null)
if (pkg == null) {
if (entry.manifest == null) {
definePackage(packageName, null, null, null, null, null,
null, null);
} else {
definePackage(packageName, entry.manifest, entry.codeBase);
}
}
}
// Create the code source object
CodeSource codeSource =
new CodeSource(entry.codeBase, entry.certificates);
if (securityManager != null) {
// Checking sealing
if (pkg != null) {
boolean sealCheck = true;
if (pkg.isSealed()) {
sealCheck = pkg.isSealed(entry.codeBase);
} else {
sealCheck = (entry.manifest == null)
|| !isPackageSealed(packageName, entry.manifest);
}
if (!sealCheck)
throw new SecurityException
("Sealing violation loading " + name + " : Package "
+ packageName + " is sealed.");
}
}
if (entry.loadedClass == null) {
synchronized (this) {
if (entry.loadedClass == null) {
clazz = defineClass(name, entry.binaryContent, 0,
entry.binaryContent.length,
codeSource);
entry.loadedClass = clazz;
entry.binaryContent = null;
entry.source = null;
entry.codeBase = null;
entry.manifest = null;
entry.certificates = null;
} else {
clazz = entry.loadedClass;
}
}
} else {
clazz = entry.loadedClass;
}
return clazz;
}
/**
* Find specified resource in local repositories. This block
* will execute under an AccessControl.doPrivilege block.
*
* @return the loaded resource, or null if the resource isn't found
*/
private ResourceEntry findResourceInternal(File file, String path){
ResourceEntry entry = new ResourceEntry();
try {
entry.source = getURI(new File(file, path));
entry.codeBase = getURL(new File(file, path));
} catch (MalformedURLException e) {
return null;
}
return entry;
}
/**
* Find specified resource in local repositories.
*
* @return the loaded resource, or null if the resource isn't found
*/
protected ResourceEntry findResourceInternal(String name, String path) {
if (!started) {
log.info(sm.getString("webappClassLoader.stopped"));
return null;
}
if ((name == null) || (path == null))
return null;
ResourceEntry entry = (ResourceEntry) resourceEntries.get(name);
if (entry != null)
return entry;
int contentLength = -1;
InputStream binaryStream = null;
int jarFilesLength = jarFiles.length;
int repositoriesLength = repositories.length;
int i;
Resource resource = null;
for (i = 0; (entry == null) && (i < repositoriesLength); i++) {
try {
String fullPath = repositories[i] + path;
Object lookupResult = resources.lookup(fullPath);
if (lookupResult instanceof Resource) {
resource = (Resource) lookupResult;
}
// Note : Not getting an exception here means the resource was
// found
if (securityManager != null) {
PrivilegedAction dp =
new PrivilegedFindResource(files[i], path);
entry = (ResourceEntry)AccessController.doPrivileged(dp);
} else {
entry = findResourceInternal(files[i], path);
}
ResourceAttributes attributes =
(ResourceAttributes) resources.getAttributes(fullPath);
contentLength = (int) attributes.getContentLength();
entry.lastModified = attributes.getLastModified();
if (resource != null) {
try {
binaryStream = resource.streamContent();
} catch (IOException e) {
return null;
}
// Register the full path for modification checking
// Note: Only syncing on a 'constant' object is needed
synchronized (allPermission) {
int j;
long[] result2 =
new long[lastModifiedDates.length + 1];
for (j = 0; j < lastModifiedDates.length; j++) {
result2[j] = lastModifiedDates[j];
}
result2[lastModifiedDates.length] = entry.lastModified;
lastModifiedDates = result2;
String[] result = new String[paths.length + 1];
for (j = 0; j < paths.length; j++) {
result[j] = paths[j];
}
result[paths.length] = fullPath;
paths = result;
}
}
} catch (NamingException e) {
}
}
if ((entry == null) && (notFoundResources.containsKey(name)))
return null;
JarEntry jarEntry = null;
synchronized (jarFiles) {
openJARs();
for (i = 0; (entry == null) && (i < jarFilesLength); i++) {
jarEntry = jarFiles[i].getJarEntry(path);
if (jarEntry != null) {
entry = new ResourceEntry();
try {
entry.codeBase = getURL(jarRealFiles[i]);
String jarFakeUrl = getURI(jarRealFiles[i]).toString();
jarFakeUrl = "jar:" + jarFakeUrl + "!/" + path;
entry.source = new URL(jarFakeUrl);
entry.lastModified = jarRealFiles[i].lastModified();
} catch (MalformedURLException e) {
return null;
}
contentLength = (int) jarEntry.getSize();
try {
entry.manifest = jarFiles[i].getManifest();
binaryStream = jarFiles[i].getInputStream(jarEntry);
} catch (IOException e) {
return null;
}
// Extract resources contained in JAR to the workdir
if (!(path.endsWith(".class"))) {
byte[] buf = new byte[1024];
File resourceFile = new File
(loaderDir, jarEntry.getName());
if (!resourceFile.exists()) {
Enumeration entries = jarFiles[i].entries();
while (entries.hasMoreElements()) {
JarEntry jarEntry2 =
(JarEntry) entries.nextElement();
if (!(jarEntry2.isDirectory())
&& (!jarEntry2.getName().endsWith
(".class"))) {
resourceFile = new File
(loaderDir, jarEntry2.getName());
// No need to check mkdirs result because an
// IOException will occur anyway
resourceFile.getParentFile().mkdirs();
FileOutputStream os = null;
InputStream is = null;
try {
is = jarFiles[i].getInputStream
(jarEntry2);
os = new FileOutputStream
(resourceFile);
while (true) {
int n = is.read(buf);
if (n <= 0) {
break;
}
os.write(buf, 0, n);
}
} catch (IOException e) {
// Ignore
} finally {
try {
if (is != null) {
is.close();
}
} catch (IOException e) {
}
try {
if (os != null) {
os.close();
}
} catch (IOException e) {
}
}
}
}
}
}
}
}
if (entry == null) {
synchronized (notFoundResources) {
notFoundResources.put(name, name);
}
return null;
}
if (binaryStream != null) {
byte[] binaryContent = new byte[contentLength];
try {
int pos = 0;
while (true) {
int n = binaryStream.read(binaryContent, pos,
binaryContent.length - pos);
if (n <= 0)
break;
pos += n;
}
binaryStream.close();
} catch (IOException e) {
e.printStackTrace();
return null;
} catch (Exception e) {
e.printStackTrace();
return null;
}
entry.binaryContent = binaryContent;
// The certificates are only available after the JarEntry
// associated input stream has been fully read
if (jarEntry != null) {
entry.certificates = jarEntry.getCertificates();
}
}
}
// Add the entry in the local resource repository
synchronized (resourceEntries) {
// Ensures that all the threads which may be in a race to load
// a particular class all end up with the same ResourceEntry
// instance
ResourceEntry entry2 = (ResourceEntry) resourceEntries.get(name);
if (entry2 == null) {
resourceEntries.put(name, entry);
} else {
entry = entry2;
}
}
return entry;
}
/**
* Returns true if the specified package name is sealed according to the
* given manifest.
*/
protected boolean isPackageSealed(String name, Manifest man) {
String path = name + "/";
Attributes attr = man.getAttributes(path);
String sealed = null;
if (attr != null) {
sealed = attr.getValue(Name.SEALED);
}
if (sealed == null) {
if ((attr = man.getMainAttributes()) != null) {
sealed = attr.getValue(Name.SEALED);
}
}
return "true".equalsIgnoreCase(sealed);
}
/**
* Finds the resource with the given name if it has previously been
* loaded and cached by this class loader, and return an input stream
* to the resource data. If this resource has not been cached, return
* <code>null</code>.
*
* @param name Name of the resource to return
*/
protected InputStream findLoadedResource(String name) {
ResourceEntry entry = (ResourceEntry) resourceEntries.get(name);
if (entry != null) {
if (entry.binaryContent != null)
return new ByteArrayInputStream(entry.binaryContent);
}
return (null);
}
/**
* Finds the class with the given name if it has previously been
* loaded and cached by this class loader, and return the Class object.
* If this class has not been cached, return <code>null</code>.
*
* @param name Name of the resource to return
*/
protected Class findLoadedClass0(String name) {
ResourceEntry entry = (ResourceEntry) resourceEntries.get(name);
if (entry != null) {
return entry.loadedClass;
}
return (null); // FIXME - findLoadedResource()
}
/**
* Refresh the system policy file, to pick up eventual changes.
*/
protected void refreshPolicy() {
try {
// The policy file may have been modified to adjust
// permissions, so we're reloading it when loading or
// reloading a Context
Policy policy = Policy.getPolicy();
policy.refresh();
} catch (AccessControlException e) {
// Some policy files may restrict this, even for the core,
// so this exception is ignored
}
}
/**
* Filter classes.
*
* @param name class name
* @return true if the class should be filtered
*/
protected boolean filter(String name) {
if (name == null)
return false;
// Looking up the package
String packageName = null;
int pos = name.lastIndexOf('.');
if (pos != -1)
packageName = name.substring(0, pos);
else
return false;
for (int i = 0; i < packageTriggers.length; i++) {
if (packageName.startsWith(packageTriggers[i]))
return true;
}
return false;
}
/**
* Validate a classname. As per SRV.9.7.2, we must restict loading of
* classes from J2SE (java.*) and classes of the servlet API
* (javax.servlet.*). That should enhance robustness and prevent a number
* of user error (where an older version of servlet.jar would be present
* in /WEB-INF/lib).
*
* @param name class name
* @return true if the name is valid
*/
protected boolean validate(String name) {
if (name == null)
return false;
if (name.startsWith("java."))
return false;
return true;
}
/**
* Check the specified JAR file, and return <code>true</code> if it does
* not contain any of the trigger classes.
*
* @param jarfile The JAR file to be checked
*
* @exception IOException if an input/output error occurs
*/
private boolean validateJarFile(File jarfile)
throws IOException {
if (triggers == null)
return (true);
JarFile jarFile = new JarFile(jarfile);
for (int i = 0; i < triggers.length; i++) {
Class clazz = null;
try {
if (parent != null) {
clazz = parent.loadClass(triggers[i]);
} else {
clazz = Class.forName(triggers[i]);
}
} catch (Throwable t) {
clazz = null;
}
if (clazz == null)
continue;
String name = triggers[i].replace('.', '/') + ".class";
if (log.isDebugEnabled())
log.debug(" Checking for " + name);
JarEntry jarEntry = jarFile.getJarEntry(name);
if (jarEntry != null) {
log.info("validateJarFile(" + jarfile +
") - jar not loaded. See Servlet Spec 2.3, "
+ "section 9.7.2. Offending class: " + name);
jarFile.close();
return (false);
}
}
jarFile.close();
return (true);
}
/**
* Get URL.
*/
protected URL getURL(File file)
throws MalformedURLException {
File realFile = file;
try {
realFile = realFile.getCanonicalFile();
} catch (IOException e) {
// Ignore
}
return realFile.toURL();
}
/**
* Get URL.
*/
protected URL getURI(File file)
throws MalformedURLException {
return jdkCompat.getURI(file);
}
/**
* Delete the specified directory, including all of its contents and
* subdirectories recursively.
*
* @param dir File object representing the directory to be deleted
*/
protected static void deleteDir(File dir) {
String files[] = dir.list();
if (files == null) {
files = new String[0];
}
for (int i = 0; i < files.length; i++) {
File file = new File(dir, files[i]);
if (file.isDirectory()) {
deleteDir(file);
} else {
file.delete();
}
}
dir.delete();
}
/**
* Log a debugging output message.
*
* @param message Message to be logged
*/
private void log(String message) {
System.out.println("WebappClassLoader: " + message);
}
/**
* Log a debugging output message with an exception.
*
* @param message Message to be logged
* @param throwable Exception to be logged
*/
private void log(String message, Throwable throwable) {
System.out.println("WebappClassLoader: " + message);
throwable.printStackTrace(System.out);
}
}