JDK8/Java8源码在线阅读
/*
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.misc;
import java.util.*;
import java.util.jar.JarFile;
import sun.misc.JarIndex;
import sun.misc.InvalidJarIndexException;
import sun.net.www.ParseUtil;
import java.util.zip.ZipEntry;
import java.util.jar.JarEntry;
import java.util.jar.Manifest;
import java.util.jar.Attributes;
import java.util.jar.Attributes.Name;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.net.HttpURLConnection;
import java.net.URLStreamHandler;
import java.net.URLStreamHandlerFactory;
import java.io.*;
import java.security.AccessController;
import java.security.AccessControlException;
import java.security.CodeSigner;
import java.security.Permission;
import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;
import java.security.cert.Certificate;
import sun.misc.FileURLMapper;
import sun.net.util.URLUtil;
import sun.security.action.GetPropertyAction;
/**
* This class is used to maintain a search path of URLs for loading classes
* and resources from both JAR files and directories.
*
* @author David Connelly
*/
public class URLClassPath {
final static String USER_AGENT_JAVA_VERSION = "UA-Java-Version";
final static String JAVA_VERSION;
private static final boolean DEBUG;
private static final boolean DEBUG_LOOKUP_CACHE;
private static final boolean DISABLE_JAR_CHECKING;
static {
JAVA_VERSION = java.security.AccessController.doPrivileged(
new GetPropertyAction("java.version"));
DEBUG = (java.security.AccessController.doPrivileged(
new GetPropertyAction("sun.misc.URLClassPath.debug")) != null);
DEBUG_LOOKUP_CACHE = (java.security.AccessController.doPrivileged(
new GetPropertyAction("sun.misc.URLClassPath.debugLookupCache")) != null);
String p = java.security.AccessController.doPrivileged(
new GetPropertyAction("sun.misc.URLClassPath.disableJarChecking"));
DISABLE_JAR_CHECKING = p != null ? p.equals("true") || p.equals("") : false;
}
/* The original search path of URLs. */
private ArrayList<URL> path = new ArrayList<URL>();
/* The stack of unopened URLs */
Stack<URL> urls = new Stack<URL>();
/* The resulting search path of Loaders */
ArrayList<Loader> loaders = new ArrayList<Loader>();
/* Map of each URL opened to its corresponding Loader */
HashMap<String, Loader> lmap = new HashMap<String, Loader>();
/* The jar protocol handler to use when creating new URLs */
private URLStreamHandler jarHandler;
/* Whether this URLClassLoader has been closed yet */
private boolean closed = false;
/**
* Creates a new URLClassPath for the given URLs. The URLs will be
* searched in the order specified for classes and resources. A URL
* ending with a '/' is assumed to refer to a directory. Otherwise,
* the URL is assumed to refer to a JAR file.
*
* @param urls the directory and JAR file URLs to search for classes
* and resources
* @param factory the URLStreamHandlerFactory to use when creating new URLs
*/
public URLClassPath(URL[] urls, URLStreamHandlerFactory factory) {
for (int i = 0; i < urls.length; i++) {
path.add(urls[i]);
}
push(urls);
if (factory != null) {
jarHandler = factory.createURLStreamHandler("jar");
}
}
public URLClassPath(URL[] urls) {
this(urls, null);
}
public synchronized List<IOException> closeLoaders() {
if (closed) {
return Collections.emptyList();
}
List<IOException> result = new LinkedList<IOException>();
for (Loader loader : loaders) {
try {
loader.close();
} catch (IOException e) {
result.add (e);
}
}
closed = true;
return result;
}
/**
* Appends the specified URL to the search path of directory and JAR
* file URLs from which to load classes and resources.
* <p>
* If the URL specified is null or is already in the list of
* URLs, then invoking this method has no effect.
*/
public synchronized void addURL(URL url) {
if (closed)
return;
synchronized (urls) {
if (url == null || path.contains(url))
return;
urls.add(0, url);
path.add(url);
if (lookupCacheURLs != null) {
// The lookup cache is no longer valid, since getLookupCache()
// does not consider the newly added url.
disableAllLookupCaches();
}
}
}
/**
* Returns the original search path of URLs.
*/
public URL[] getURLs() {
synchronized (urls) {
return path.toArray(new URL[path.size()]);
}
}
/**
* Finds the resource with the specified name on the URL search path
* or null if not found or security check fails.
*
* @param name the name of the resource
* @param check whether to perform a security check
* @return a <code>URL</code> for the resource, or <code>null</code>
* if the resource could not be found.
*/
public URL findResource(String name, boolean check) {
Loader loader;
int[] cache = getLookupCache(name);
for (int i = 0; (loader = getNextLoader(cache, i)) != null; i++) {
URL url = loader.findResource(name, check);
if (url != null) {
return url;
}
}
return null;
}
/**
* Finds the first Resource on the URL search path which has the specified
* name. Returns null if no Resource could be found.
*
* @param name the name of the Resource
* @param check whether to perform a security check
* @return the Resource, or null if not found
*/
public Resource getResource(String name, boolean check) {
if (DEBUG) {
System.err.println("URLClassPath.getResource(\"" + name + "\")");
}
Loader loader;
int[] cache = getLookupCache(name);
for (int i = 0; (loader = getNextLoader(cache, i)) != null; i++) {
Resource res = loader.getResource(name, check);
if (res != null) {
return res;
}
}
return null;
}
/**
* Finds all resources on the URL search path with the given name.
* Returns an enumeration of the URL objects.
*
* @param name the resource name
* @return an Enumeration of all the urls having the specified name
*/
public Enumeration<URL> findResources(final String name,
final boolean check) {
return new Enumeration<URL>() {
private int index = 0;
private int[] cache = getLookupCache(name);
private URL url = null;
private boolean next() {
if (url != null) {
return true;
} else {
Loader loader;
while ((loader = getNextLoader(cache, index++)) != null) {
url = loader.findResource(name, check);
if (url != null) {
return true;
}
}
return false;
}
}
public boolean hasMoreElements() {
return next();
}
public URL nextElement() {
if (!next()) {
throw new NoSuchElementException();
}
URL u = url;
url = null;
return u;
}
};
}
public Resource getResource(String name) {
return getResource(name, true);
}
/**
* Finds all resources on the URL search path with the given name.
* Returns an enumeration of the Resource objects.
*
* @param name the resource name
* @return an Enumeration of all the resources having the specified name
*/
public Enumeration<Resource> getResources(final String name,
final boolean check) {
return new Enumeration<Resource>() {
private int index = 0;
private int[] cache = getLookupCache(name);
private Resource res = null;
private boolean next() {
if (res != null) {
return true;
} else {
Loader loader;
while ((loader = getNextLoader(cache, index++)) != null) {
res = loader.getResource(name, check);
if (res != null) {
return true;
}
}
return false;
}
}
public boolean hasMoreElements() {
return next();
}
public Resource nextElement() {
if (!next()) {
throw new NoSuchElementException();
}
Resource r = res;
res = null;
return r;
}
};
}
public Enumeration<Resource> getResources(final String name) {
return getResources(name, true);
}
private static volatile boolean lookupCacheEnabled
= "true".equals(VM.getSavedProperty("sun.cds.enableSharedLookupCache"));
private URL[] lookupCacheURLs;
private ClassLoader lookupCacheLoader;
synchronized void initLookupCache(ClassLoader loader) {
if ((lookupCacheURLs = getLookupCacheURLs(loader)) != null) {
lookupCacheLoader = loader;
} else {
// This JVM instance does not support lookup cache.
disableAllLookupCaches();
}
}
static void disableAllLookupCaches() {
lookupCacheEnabled = false;
}
private static native URL[] getLookupCacheURLs(ClassLoader loader);
private static native int[] getLookupCacheForClassLoader(ClassLoader loader,
String name);
private static native boolean knownToNotExist0(ClassLoader loader,
String className);
synchronized boolean knownToNotExist(String className) {
if (lookupCacheURLs != null && lookupCacheEnabled) {
return knownToNotExist0(lookupCacheLoader, className);
}
// Don't know if this class exists or not -- need to do a full search.
return false;
}
/**
* Returns an array of the index to lookupCacheURLs that may
* contain the specified resource. The values in the returned
* array are in strictly ascending order and must be a valid index
* to lookupCacheURLs array.
*
* This method returns an empty array if the specified resource
* cannot be found in this URLClassPath. If there is no lookup
* cache or it's disabled, this method returns null and the lookup
* should search the entire classpath.
*
* Example: if lookupCacheURLs contains {a.jar, b.jar, c.jar, d.jar}
* and package "foo" only exists in a.jar and c.jar,
* getLookupCache("foo/Bar.class") will return {0, 2}
*
* @param name the resource name
* @return an array of the index to lookupCacheURLs that may contain the
* specified resource; or null if no lookup cache is used.
*/
private synchronized int[] getLookupCache(String name) {
if (lookupCacheURLs == null || !lookupCacheEnabled) {
return null;
}
int[] cache = getLookupCacheForClassLoader(lookupCacheLoader, name);
if (cache != null && cache.length > 0) {
int maxindex = cache[cache.length - 1]; // cache[] is strictly ascending.
if (!ensureLoaderOpened(maxindex)) {
if (DEBUG_LOOKUP_CACHE) {
System.out.println("Expanded loaders FAILED " +
loaders.size() + " for maxindex=" + maxindex);
}
return null;
}
}
return cache;
}
private boolean ensureLoaderOpened(int index) {
if (loaders.size() <= index) {
// Open all Loaders up to, and including, index
if (getLoader(index) == null) {
return false;
}
if (!lookupCacheEnabled) {
// cache was invalidated as the result of the above call.
return false;
}
if (DEBUG_LOOKUP_CACHE) {
System.out.println("Expanded loaders " + loaders.size() +
" to index=" + index);
}
}
return true;
}
/*
* The CLASS-PATH attribute was expanded by the VM when building
* the resource lookup cache in the same order as the getLoader
* method does. This method validates if the URL from the lookup
* cache matches the URL of the Loader at the given index;
* otherwise, this method disables the lookup cache.
*/
private synchronized void validateLookupCache(int index,
String urlNoFragString) {
if (lookupCacheURLs != null && lookupCacheEnabled) {
if (index < lookupCacheURLs.length &&
urlNoFragString.equals(
URLUtil.urlNoFragString(lookupCacheURLs[index]))) {
return;
}
if (DEBUG || DEBUG_LOOKUP_CACHE) {
System.out.println("WARNING: resource lookup cache invalidated "
+ "for lookupCacheLoader at " + index);
}
disableAllLookupCaches();
}
}
/**
* Returns the next Loader that may contain the resource to
* lookup. If the given cache is null, return loaders.get(index)
* that may be lazily created; otherwise, cache[index] is the next
* Loader that may contain the resource to lookup and so returns
* loaders.get(cache[index]).
*
* If cache is non-null, loaders.get(cache[index]) must be present.
*
* @param cache lookup cache. If null, search the entire class path
* @param index index to the given cache array; or to the loaders list.
*/
private synchronized Loader getNextLoader(int[] cache, int index) {
if (closed) {
return null;
}
if (cache != null) {
if (index < cache.length) {
Loader loader = loaders.get(cache[index]);
if (DEBUG_LOOKUP_CACHE) {
System.out.println("HASCACHE: Loading from : " + cache[index]
+ " = " + loader.getBaseURL());
}
return loader;
} else {
return null; // finished iterating over cache[]
}
} else {
return getLoader(index);
}
}
/*
* Returns the Loader at the specified position in the URL search
* path. The URLs are opened and expanded as needed. Returns null
* if the specified index is out of range.
*/
private synchronized Loader getLoader(int index) {
if (closed) {
return null;
}
// Expand URL search path until the request can be satisfied
// or the URL stack is empty.
while (loaders.size() < index + 1) {
// Pop the next URL from the URL stack
URL url;
synchronized (urls) {
if (urls.empty()) {
return null;
} else {
url = urls.pop();
}
}
// Skip this URL if it already has a Loader. (Loader
// may be null in the case where URL has not been opened
// but is referenced by a JAR index.)
String urlNoFragString = URLUtil.urlNoFragString(url);
if (lmap.containsKey(urlNoFragString)) {
continue;
}
// Otherwise, create a new Loader for the URL.
Loader loader;
try {
loader = getLoader(url);
// If the loader defines a local class path then add the
// URLs to the list of URLs to be opened.
URL[] urls = loader.getClassPath();
if (urls != null) {
push(urls);
}
} catch (IOException e) {
// Silently ignore for now...
continue;
}
// Finally, add the Loader to the search path.
validateLookupCache(loaders.size(), urlNoFragString);
loaders.add(loader);
lmap.put(urlNoFragString, loader);
}
if (DEBUG_LOOKUP_CACHE) {
System.out.println("NOCACHE: Loading from : " + index );
}
return loaders.get(index);
}
/*
* Returns the Loader for the specified base URL.
*/
private Loader getLoader(final URL url) throws IOException {
try {
return java.security.AccessController.doPrivileged(
new java.security.PrivilegedExceptionAction<Loader>() {
public Loader run() throws IOException {
String file = url.getFile();
if (file != null && file.endsWith("/")) {
if ("file".equals(url.getProtocol())) {
return new FileLoader(url);
} else {
return new Loader(url);
}
} else {
return new JarLoader(url, jarHandler, lmap);
}
}
});
} catch (java.security.PrivilegedActionException pae) {
throw (IOException)pae.getException();
}
}
/*
* Pushes the specified URLs onto the list of unopened URLs.
*/
private void push(URL[] us) {
synchronized (urls) {
for (int i = us.length - 1; i >= 0; --i) {
urls.push(us[i]);
}
}
}
/**
* Convert class path specification into an array of file URLs.
*
* The path of the file is encoded before conversion into URL
* form so that reserved characters can safely appear in the path.
*/
public static URL[] pathToURLs(String path) {
StringTokenizer st = new StringTokenizer(path, File.pathSeparator);
URL[] urls = new URL[st.countTokens()];
int count = 0;
while (st.hasMoreTokens()) {
File f = new File(st.nextToken());
try {
f = new File(f.getCanonicalPath());
} catch (IOException x) {
// use the non-canonicalized filename
}
try {
urls[count++] = ParseUtil.fileToEncodedURL(f);
} catch (IOException x) { }
}
if (urls.length != count) {
URL[] tmp = new URL[count];
System.arraycopy(urls, 0, tmp, 0, count);
urls = tmp;
}
return urls;
}
/*
* Check whether the resource URL should be returned.
* Return null on security check failure.
* Called by java.net.URLClassLoader.
*/
public URL checkURL(URL url) {
try {
check(url);
} catch (Exception e) {
return null;
}
return url;
}
/*
* Check whether the resource URL should be returned.
* Throw exception on failure.
* Called internally within this file.
*/
static void check(URL url) throws IOException {
SecurityManager security = System.getSecurityManager();
if (security != null) {
URLConnection urlConnection = url.openConnection();
Permission perm = urlConnection.getPermission();
if (perm != null) {
try {
security.checkPermission(perm);
} catch (SecurityException se) {
// fallback to checkRead/checkConnect for pre 1.2
// security managers
if ((perm instanceof java.io.FilePermission) &&
perm.getActions().indexOf("read") != -1) {
security.checkRead(perm.getName());
} else if ((perm instanceof
java.net.SocketPermission) &&
perm.getActions().indexOf("connect") != -1) {
URL locUrl = url;
if (urlConnection instanceof JarURLConnection) {
locUrl = ((JarURLConnection)urlConnection).getJarFileURL();
}
security.checkConnect(locUrl.getHost(),
locUrl.getPort());
} else {
throw se;
}
}
}
}
}
/**
* Inner class used to represent a loader of resources and classes
* from a base URL.
*/
private static class Loader implements Closeable {
private final URL base;
private JarFile jarfile; // if this points to a jar file
/*
* Creates a new Loader for the specified URL.
*/
Loader(URL url) {
base = url;
}
/*
* Returns the base URL for this Loader.
*/
URL getBaseURL() {
return base;
}
URL findResource(final String name, boolean check) {
URL url;
try {
url = new URL(base, ParseUtil.encodePath(name, false));
} catch (MalformedURLException e) {
throw new IllegalArgumentException("name");
}
try {
if (check) {
URLClassPath.check(url);
}
/*
* For a HTTP connection we use the HEAD method to
* check if the resource exists.
*/
URLConnection uc = url.openConnection();
if (uc instanceof HttpURLConnection) {
HttpURLConnection hconn = (HttpURLConnection)uc;
hconn.setRequestMethod("HEAD");
if (hconn.getResponseCode() >= HttpURLConnection.HTTP_BAD_REQUEST) {
return null;
}
} else {
// our best guess for the other cases
uc.setUseCaches(false);
InputStream is = uc.getInputStream();
is.close();
}
return url;
} catch (Exception e) {
return null;
}
}
Resource getResource(final String name, boolean check) {
final URL url;
try {
url = new URL(base, ParseUtil.encodePath(name, false));
} catch (MalformedURLException e) {
throw new IllegalArgumentException("name");
}
final URLConnection uc;
try {
if (check) {
URLClassPath.check(url);
}
uc = url.openConnection();
InputStream in = uc.getInputStream();
if (uc instanceof JarURLConnection) {
/* Need to remember the jar file so it can be closed
* in a hurry.
*/
JarURLConnection juc = (JarURLConnection)uc;
jarfile = JarLoader.checkJar(juc.getJarFile());
}
} catch (Exception e) {
return null;
}
return new Resource() {
public String getName() { return name; }
public URL getURL() { return url; }
public URL getCodeSourceURL() { return base; }
public InputStream getInputStream() throws IOException {
return uc.getInputStream();
}
public int getContentLength() throws IOException {
return uc.getContentLength();
}
};
}
/*
* Returns the Resource for the specified name, or null if not
* found or the caller does not have the permission to get the
* resource.
*/
Resource getResource(final String name) {
return getResource(name, true);
}
/*
* close this loader and release all resources
* method overridden in sub-classes
*/
public void close () throws IOException {
if (jarfile != null) {
jarfile.close();
}
}
/*
* Returns the local class path for this loader, or null if none.
*/
URL[] getClassPath() throws IOException {
return null;
}
}
/*
* Inner class used to represent a Loader of resources from a JAR URL.
*/
static class JarLoader extends Loader {
private JarFile jar;
private URL csu;
private JarIndex index;
private MetaIndex metaIndex;
private URLStreamHandler handler;
private HashMap<String, Loader> lmap;
private boolean closed = false;
private static final sun.misc.JavaUtilZipFileAccess zipAccess =
sun.misc.SharedSecrets.getJavaUtilZipFileAccess();
/*
* Creates a new JarLoader for the specified URL referring to
* a JAR file.
*/
JarLoader(URL url, URLStreamHandler jarHandler,
HashMap<String, Loader> loaderMap)
throws IOException
{
super(new URL("jar", "", -1, url + "!/", jarHandler));
csu = url;
handler = jarHandler;
lmap = loaderMap;
if (!isOptimizable(url)) {
ensureOpen();
} else {
String fileName = url.getFile();
if (fileName != null) {
fileName = ParseUtil.decode(fileName);
File f = new File(fileName);
metaIndex = MetaIndex.forJar(f);
// If the meta index is found but the file is not
// installed, set metaIndex to null. A typical
// senario is charsets.jar which won't be installed
// when the user is running in certain locale environment.
// The side effect of null metaIndex will cause
// ensureOpen get called so that IOException is thrown.
if (metaIndex != null && !f.exists()) {
metaIndex = null;
}
}
// metaIndex is null when either there is no such jar file
// entry recorded in meta-index file or such jar file is
// missing in JRE. See bug 6340399.
if (metaIndex == null) {
ensureOpen();
}
}
}
@Override
public void close () throws IOException {
// closing is synchronized at higher level
if (!closed) {
closed = true;
// in case not already open.
ensureOpen();
jar.close();
}
}
JarFile getJarFile () {
return jar;
}
private boolean isOptimizable(URL url) {
return "file".equals(url.getProtocol());
}
private void ensureOpen() throws IOException {
if (jar == null) {
try {
java.security.AccessController.doPrivileged(
new java.security.PrivilegedExceptionAction<Void>() {
public Void run() throws IOException {
if (DEBUG) {
System.err.println("Opening " + csu);
Thread.dumpStack();
}
jar = getJarFile(csu);
index = JarIndex.getJarIndex(jar, metaIndex);
if (index != null) {
String[] jarfiles = index.getJarFiles();
// Add all the dependent URLs to the lmap so that loaders
// will not be created for them by URLClassPath.getLoader(int)
// if the same URL occurs later on the main class path. We set
// Loader to null here to avoid creating a Loader for each
// URL until we actually need to try to load something from them.
for(int i = 0; i < jarfiles.length; i++) {
try {
URL jarURL = new URL(csu, jarfiles[i]);
// If a non-null loader already exists, leave it alone.
String urlNoFragString = URLUtil.urlNoFragString(jarURL);
if (!lmap.containsKey(urlNoFragString)) {
lmap.put(urlNoFragString, null);
}
} catch (MalformedURLException e) {
continue;
}
}
}
return null;
}
}
);
} catch (java.security.PrivilegedActionException pae) {
throw (IOException)pae.getException();
}
}
}
/* Throws if the given jar file is does not start with the correct LOC */
static JarFile checkJar(JarFile jar) throws IOException {
if (System.getSecurityManager() != null && !DISABLE_JAR_CHECKING
&& !zipAccess.startsWithLocHeader(jar)) {
IOException x = new IOException("Invalid Jar file");
try {
jar.close();
} catch (IOException ex) {
x.addSuppressed(ex);
}
throw x;
}
return jar;
}
private JarFile getJarFile(URL url) throws IOException {
// Optimize case where url refers to a local jar file
if (isOptimizable(url)) {
FileURLMapper p = new FileURLMapper (url);
if (!p.exists()) {
throw new FileNotFoundException(p.getPath());
}
return checkJar(new JarFile(p.getPath()));
}
URLConnection uc = getBaseURL().openConnection();
uc.setRequestProperty(USER_AGENT_JAVA_VERSION, JAVA_VERSION);
JarFile jarFile = ((JarURLConnection)uc).getJarFile();
return checkJar(jarFile);
}
/*
* Returns the index of this JarLoader if it exists.
*/
JarIndex getIndex() {
try {
ensureOpen();
} catch (IOException e) {
throw new InternalError(e);
}
return index;
}
/*
* Creates the resource and if the check flag is set to true, checks if
* is its okay to return the resource.
*/
Resource checkResource(final String name, boolean check,
final JarEntry entry) {
final URL url;
try {
url = new URL(getBaseURL(), ParseUtil.encodePath(name, false));
if (check) {
URLClassPath.check(url);
}
} catch (MalformedURLException e) {
return null;
// throw new IllegalArgumentException("name");
} catch (IOException e) {
return null;
} catch (AccessControlException e) {
return null;
}
return new Resource() {
public String getName() { return name; }
public URL getURL() { return url; }
public URL getCodeSourceURL() { return csu; }
public InputStream getInputStream() throws IOException
{ return jar.getInputStream(entry); }
public int getContentLength()
{ return (int)entry.getSize(); }
public Manifest getManifest() throws IOException
{ return jar.getManifest(); };
public Certificate[] getCertificates()
{ return entry.getCertificates(); };
public CodeSigner[] getCodeSigners()
{ return entry.getCodeSigners(); };
};
}
/*
* Returns true iff atleast one resource in the jar file has the same
* package name as that of the specified resource name.
*/
boolean validIndex(final String name) {
String packageName = name;
int pos;
if((pos = name.lastIndexOf("/")) != -1) {
packageName = name.substring(0, pos);
}
String entryName;
ZipEntry entry;
Enumeration<JarEntry> enum_ = jar.entries();
while (enum_.hasMoreElements()) {
entry = enum_.nextElement();
entryName = entry.getName();
if((pos = entryName.lastIndexOf("/")) != -1)
entryName = entryName.substring(0, pos);
if (entryName.equals(packageName)) {
return true;
}
}
return false;
}
/*
* Returns the URL for a resource with the specified name
*/
URL findResource(final String name, boolean check) {
Resource rsc = getResource(name, check);
if (rsc != null) {
return rsc.getURL();
}
return null;
}
/*
* Returns the JAR Resource for the specified name.
*/
Resource getResource(final String name, boolean check) {
if (metaIndex != null) {
if (!metaIndex.mayContain(name)) {
return null;
}
}
try {
ensureOpen();
} catch (IOException e) {
throw new InternalError(e);
}
final JarEntry entry = jar.getJarEntry(name);
if (entry != null)
return checkResource(name, check, entry);
if (index == null)
return null;
HashSet<String> visited = new HashSet<String>();
return getResource(name, check, visited);
}
/*
* Version of getResource() that tracks the jar files that have been
* visited by linking through the index files. This helper method uses
* a HashSet to store the URLs of jar files that have been searched and
* uses it to avoid going into an infinite loop, looking for a
* non-existent resource
*/
Resource getResource(final String name, boolean check,
Set<String> visited) {
Resource res;
String[] jarFiles;
int count = 0;
LinkedList<String> jarFilesList = null;
/* If there no jar files in the index that can potential contain
* this resource then return immediately.
*/
if((jarFilesList = index.get(name)) == null)
return null;
do {
int size = jarFilesList.size();
jarFiles = jarFilesList.toArray(new String[size]);
/* loop through the mapped jar file list */
while(count < size) {
String jarName = jarFiles[count++];
JarLoader newLoader;
final URL url;
try{
url = new URL(csu, jarName);
String urlNoFragString = URLUtil.urlNoFragString(url);
if ((newLoader = (JarLoader)lmap.get(urlNoFragString)) == null) {
/* no loader has been set up for this jar file
* before
*/
newLoader = AccessController.doPrivileged(
new PrivilegedExceptionAction<JarLoader>() {
public JarLoader run() throws IOException {
return new JarLoader(url, handler,
lmap);
}
});
/* this newly opened jar file has its own index,
* merge it into the parent's index, taking into
* account the relative path.
*/
JarIndex newIndex = newLoader.getIndex();
if(newIndex != null) {
int pos = jarName.lastIndexOf("/");
newIndex.merge(this.index, (pos == -1 ?
null : jarName.substring(0, pos + 1)));
}
/* put it in the global hashtable */
lmap.put(urlNoFragString, newLoader);
}
} catch (java.security.PrivilegedActionException pae) {
continue;
} catch (MalformedURLException e) {
continue;
}
/* Note that the addition of the url to the list of visited
* jars incorporates a check for presence in the hashmap
*/
boolean visitedURL = !visited.add(URLUtil.urlNoFragString(url));
if (!visitedURL) {
try {
newLoader.ensureOpen();
} catch (IOException e) {
throw new InternalError(e);
}
final JarEntry entry = newLoader.jar.getJarEntry(name);
if (entry != null) {
return newLoader.checkResource(name, check, entry);
}
/* Verify that at least one other resource with the
* same package name as the lookedup resource is
* present in the new jar
*/
if (!newLoader.validIndex(name)) {
/* the mapping is wrong */
throw new InvalidJarIndexException("Invalid index");
}
}
/* If newLoader is the current loader or if it is a
* loader that has already been searched or if the new
* loader does not have an index then skip it
* and move on to the next loader.
*/
if (visitedURL || newLoader == this ||
newLoader.getIndex() == null) {
continue;
}
/* Process the index of the new loader
*/
if((res = newLoader.getResource(name, check, visited))
!= null) {
return res;
}
}
// Get the list of jar files again as the list could have grown
// due to merging of index files.
jarFilesList = index.get(name);
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