/*
* Copyright (C) 2007 The Android Open Source Project
*
* 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.
*/
package dalvik.system;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.net.MalformedURLException;
import dalvik.system.DexFile;
/**
* Provides a simple {@link ClassLoader} implementation that operates on a list
* of files and directories in the local file system, but does not attempt to
* load classes from the network. Android uses this class for its system class
* loader and for its application class loader(s).
*
* @since Android 1.0
*/
public class PathClassLoader extends ClassLoader {
private final String path;
private final String libPath;
private boolean initialized;
private String[] mPaths;
private File[] mFiles;
private ZipFile[] mZips;
private DexFile[] mDexs;
private String[] mLibPaths;
/**
* Creates a {@code PathClassLoader} that operates on a given list of files
* and directories. This method is equivalent to calling
* {@link #PathClassLoader(String, String, ClassLoader) with a {@code null}
* value for the second argument (see description there).
*
* @param path
* the list of files and directories
*
* @param parent
* the parent class loader
*/
public PathClassLoader(String path, ClassLoader parent) {
this(path, null, parent);
}
/**
* Creates a {@code PathClassLoader} that operates on two given lists of
* files and directories. The entries of the first list should be one of the
* following:
* <ul>
* <li>Directories containing classes or resources.
* <li>JAR/ZIP/APK files, possibly containing a "classes.dex" file.
* <li>"classes.dex" files.
* </ul>
* The entries of the second list should be directories containing native
* library files. Both lists are separated using the character specified by
* the "path.separator" system property, which, on Android, defaults to ":".
*
* @param path
* the list of files and directories containing classes and
* resources
*
* @param libPath
* the list of directories containing native libraries
*
* @param parent
* the parent class loader
*/
public PathClassLoader(String path, String libPath, ClassLoader parent) {
super(parent);
if (path == null)
throw new NullPointerException();
this.path = path;
this.libPath = libPath;
}
private synchronized void ensureInit() {
if (initialized) {
return;
}
initialized = true;
mPaths = path.split(":");
int length = mPaths.length;
//System.out.println("PathClassLoader: " + mPaths);
mFiles = new File[length];
mZips = new ZipFile[length];
mDexs = new DexFile[length];
boolean wantDex =
System.getProperty("android.vm.dexfile", "").equals("true");
/* open all Zip and DEX files up front */
for (int i = 0; i < length; i++) {
//System.out.println("My path is: " + mPaths[i]);
File pathFile = new File(mPaths[i]);
mFiles[i] = pathFile;
if (pathFile.isFile()) {
try {
mZips[i] = new ZipFile(pathFile);
}
catch (IOException ioex) {
// expecting IOException and ZipException
//System.out.println("Failed opening '" + archive + "': " + ioex);
//ioex.printStackTrace();
}
if (wantDex) {
/* we need both DEX and Zip, because dex has no resources */
try {
mDexs[i] = new DexFile(pathFile);
}
catch (IOException ioex) {}
}
}
}
/*
* Prep for native library loading.
*/
String pathList = System.getProperty("java.library.path", ".");
String pathSep = System.getProperty("path.separator", ":");
String fileSep = System.getProperty("file.separator", "/");
if (libPath != null) {
if (pathList.length() > 0) {
pathList += pathSep + libPath;
}
else {
pathList = libPath;
}
}
mLibPaths = pathList.split(pathSep);
length = mLibPaths.length;
// Add a '/' to the end so we don't have to do the property lookup
// and concatenation later.
for (int i = 0; i < length; i++) {
if (!mLibPaths[i].endsWith(fileSep))
mLibPaths[i] += fileSep;
if (false)
System.out.println("Native lib path: " + mLibPaths[i]);
}
}
/**
* Finds a class. This method is called by {@code loadClass()} after the
* parent ClassLoader has failed to find a loaded class of the same name.
*
* @param name
* The name of the class to search for, in a human-readable form
* like "java.lang.String" or "java.net.URLClassLoader$3$1".
* @return the {@link Class} object representing the class
* @throws ClassNotFoundException
* if the class cannot be found
*/
@Override
protected Class<?> findClass(String name) throws ClassNotFoundException
{
ensureInit();
//System.out.println("PathClassLoader " + this + ": findClass '" + name + "'");
byte[] data = null;
int length = mPaths.length;
for (int i = 0; i < length; i++) {
//System.out.println("My path is: " + mPaths[i]);
if (mDexs[i] != null) {
String slashName = name.replace('.', '/');
Class clazz = mDexs[i].loadClass(slashName, this);
if (clazz != null)
return clazz;
} else if (mZips[i] != null) {
String fileName = name.replace('.', '/') + ".class";
data = loadFromArchive(mZips[i], fileName);
} else {
File pathFile = mFiles[i];
if (pathFile.isDirectory()) {
String fileName =
mPaths[i] + "/" + name.replace('.', '/') + ".class";
data = loadFromDirectory(fileName);
} else {
//System.out.println("PathClassLoader: can't find '"
// + mPaths[i] + "'");
}
}
/* --this doesn't work in current version of Dalvik--
if (data != null) {
System.out.println("--- Found class " + name
+ " in zip[" + i + "] '" + mZips[i].getName() + "'");
int dotIndex = name.lastIndexOf('.');
if (dotIndex != -1) {
String packageName = name.substring(0, dotIndex);
synchronized (this) {
Package packageObj = getPackage(packageName);
if (packageObj == null) {
definePackage(packageName, null, null,
null, null, null, null, null);
}
}
}
return defineClass(name, data, 0, data.length);
}
*/
}
throw new ClassNotFoundException(name + " in loader " + this);
}
/**
* Finds a resource. This method is called by {@code getResource()} after
* the parent ClassLoader has failed to find a loaded resource of the same
* name.
*
* @param name
* The name of the resource to find
* @return the location of the resource as a URL, or {@code null} if the
* resource is not found.
*/
@Override
protected URL findResource(String name) {
ensureInit();
//java.util.logging.Logger.global.severe("findResource: " + name);
int length = mPaths.length;
for (int i = 0; i < length; i++) {
URL result = findResource(name, i);
if(result != null) {
return result;
}
}
return null;
}
/**
* Finds an enumeration of URLs for the resource with the specified name.
*
* @param resName
* the name of the resource to find.
* @return an enumeration of {@code URL} objects for the requested resource.
* @since Android 1.0
*/
@Override
protected Enumeration<URL> findResources(String resName) {
ensureInit();
int length = mPaths.length;
ArrayList<URL> results = new ArrayList<URL>();
for (int i = 0; i < length; i++) {
URL result = findResource(resName, i);
if(result != null) {
results.add(result);
}
}
return new EnumerateListArray<URL>(results);
}
private URL findResource(String name, int i) {
File pathFile = mFiles[i];
ZipFile zip = mZips[i];
if (zip != null) {
if (isInArchive(zip, name)) {
//System.out.println(" found " + name + " in " + pathFile);
try {
// File.toURL() is compliant with RFC 1738 in always
// creating absolute path names. If we construct the
// URL by concatenating strings, we might end up with
// illegal URLs for relative names.
return new URL("jar:" + pathFile.toURL() + "!/" + name);
}
catch (MalformedURLException e) {
throw new RuntimeException(e);
}
}
} else if (pathFile.isDirectory()) {
File dataFile = new File(mPaths[i] + "/" + name);
if (dataFile.exists()) {
//System.out.println(" found resource " + name);
try {
// Same as archive case regarding URL construction.
return dataFile.toURL();
}
catch (MalformedURLException e) {
throw new RuntimeException(e);
}
}
} else if (pathFile.isFile()) {
} else {
System.err.println("PathClassLoader: can't find '"
+ mPaths[i] + "'");
}
return null;
}
/*
* Load the contents of a file from a file in a directory.
*
* Returns null if the class wasn't found.
*/
private byte[] loadFromDirectory(String path) {
RandomAccessFile raf;
byte[] fileData;
//System.out.println("Trying to load from " + path);
try {
raf = new RandomAccessFile(path, "r");
}
catch (FileNotFoundException fnfe) {
//System.out.println(" Not found: " + path);
return null;
}
try {
fileData = new byte[(int) raf.length()];
raf.read(fileData);
raf.close();
}
catch (IOException ioe) {
System.err.println("Error reading from " + path);
// swallow it, return null instead
fileData = null;
}
return fileData;
}
/*
* Load a class from a file in an archive. We currently assume that
* the file is a Zip archive.
*
* Returns null if the class wasn't found.
*/
private byte[] loadFromArchive(ZipFile zip, String name) {
ZipEntry entry;
entry = zip.getEntry(name);
if (entry == null)
return null;
ByteArrayOutputStream byteStream;
InputStream stream;
int count;
/*
* Copy the data out of the stream. Because we got the ZipEntry
* from a ZipFile, the uncompressed size is known, and we can set
* the initial size of the ByteArrayOutputStream appropriately.
*/
try {
stream = zip.getInputStream(entry);
byteStream = new ByteArrayOutputStream((int) entry.getSize());
byte[] buf = new byte[4096];
while ((count = stream.read(buf)) > 0)
byteStream.write(buf, 0, count);
stream.close();
}
catch (IOException ioex) {
//System.out.println("Failed extracting '" + archive + "': " +ioex);
return null;
}
//System.out.println(" loaded from Zip");
return byteStream.toByteArray();
}
/*
* Figure out if "name" is a member of "archive".
*/
private boolean isInArchive(ZipFile zip, String name) {
return zip.getEntry(name) != null;
}
/**
* Finds a native library. This method is called after the parent
* ClassLoader has failed to find a native library of the same name.
*
* @param libname
* The name of the library to find
* @return the complete path of the library, or {@code null} if the library
* is not found.
*/
protected String findLibrary(String libname) {
ensureInit();
String fileName = System.mapLibraryName(libname);
for (int i = 0; i < mLibPaths.length; i++) {
String pathName = mLibPaths[i] + fileName;
File test = new File(pathName);
if (test.exists())
return pathName;
}
return null;
}
/**
* Returns package information for the given package. Unfortunately, the
* PathClassLoader doesn't really have this information, and as a non-secure
* ClassLoader, it isn't even required to, according to the spec. Yet, we
* want to provide it, in order to make all those hopeful callers of
* <code>myClass.getPackage().getName()</code> happy. Thus we construct a
* Package object the first time it is being requested and fill most of the
* fields with dummy values. The Package object is then put into the
* ClassLoader's Package cache, so we see the same one next time. We don't
* create Package objects for null arguments or for the default package.
* <p>
* There a limited chance that we end up with multiple Package objects
* representing the same package: It can happen when when a package is
* scattered across different JAR files being loaded by different
* ClassLoaders. Rather unlikely, and given that this whole thing is more or
* less a workaround, probably not worth the effort.
*
* @param name
* the name of the class
* @return the package information for the class, or {@code null} if there
* is not package information available for it
*/
@Override
protected Package getPackage(String name) {
if (name != null && !"".equals(name)) {
synchronized(this) {
Package pack = super.getPackage(name);
if (pack == null) {
pack = definePackage(name, "Unknown", "0.0", "Unknown", "Unknown", "0.0", "Unknown", null);
}
return pack;
}
}
return null;
}
/*
* Create an Enumeration for an ArrayList.
*/
private static class EnumerateListArray<T> implements Enumeration<T> {
private final ArrayList mList;
private int i = 0;
EnumerateListArray(ArrayList list) {
mList = list;
}
public boolean hasMoreElements() {
return i < mList.size();
}
public T nextElement() {
if (i >= mList.size())
throw new NoSuchElementException();
return (T) mList.get(i++);
}
};
}
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