jodd.util.ClassLoaderUtil Maven / Gradle / Ivy
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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package jodd.util;
import jodd.core.JoddCore;
import jodd.io.FileUtil;
import jodd.io.StreamUtil;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Set;
import java.util.TreeSet;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
/**
* Utilities to manipulate class path, define and find classes etc.
*/
public class ClassLoaderUtil {
// ---------------------------------------------------------------- default class loader
/**
* Returns class loader of a class, considering the security manager.
*/
public static ClassLoader getClassLoader(final Class clazz) {
if (System.getSecurityManager() == null) {
return clazz.getClassLoader();
}
else {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public ClassLoader run() {
return clazz.getClassLoader();
}
});
}
}
/**
* Returns default class loader. By default, it is {@link #getContextClassLoader() threads context class loader}.
* If this one is null, then class loader of the caller class is returned.
*/
public static ClassLoader getDefaultClassLoader() {
ClassLoader cl = getContextClassLoader();
if (cl == null) {
Class callerClass = ReflectUtil.getCallerClass(2);
cl = callerClass.getClassLoader();
}
return cl;
}
/**
* Returns thread context class loader.
*/
public static ClassLoader getContextClassLoader() {
if (System.getSecurityManager() == null) {
return Thread.currentThread().getContextClassLoader();
}
else {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public ClassLoader run() {
return Thread.currentThread().getContextClassLoader();
}
});
}
}
/**
* Returns system class loader.
*/
public static ClassLoader getSystemClassLoader() {
if (System.getSecurityManager() == null) {
return ClassLoader.getSystemClassLoader();
}
else {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public ClassLoader run() {
return ClassLoader.getSystemClassLoader();
}
});
}
}
// ---------------------------------------------------------------- add class path
/**
* Adds additional file or path to classpath during runtime.
* @see #addUrlToClassPath(java.net.URL, ClassLoader)
*/
public static void addFileToClassPath(File path, ClassLoader classLoader) {
try {
addUrlToClassPath(FileUtil.toURL(path), classLoader);
} catch (MalformedURLException muex) {
throw new IllegalArgumentException("Invalid path: " + path, muex);
}
}
/**
* Adds the content pointed by the URL to the classpath during runtime.
* Uses reflection since addURL method of
* URLClassLoader is protected.
*/
public static void addUrlToClassPath(URL url, ClassLoader classLoader) {
try {
ReflectUtil.invokeDeclared(URLClassLoader.class, classLoader, "addURL",
new Class[]{URL.class}, new Object[]{url});
} catch (Exception ex) {
throw new IllegalArgumentException("Add URL failed: " + url, ex);
}
}
// ---------------------------------------------------------------- define class
/**
* Defines a class from byte array into the system class loader.
* @see #defineClass(String, byte[], ClassLoader)
*/
public static Class defineClass(String className, byte[] classData) {
return defineClass(className, classData, getDefaultClassLoader());
}
/**
* Defines a class from byte array into the specified class loader.
* Warning: this is a hack!
* @param className optional class name, may be null
* @param classData bytecode data
* @param classLoader classloader that will load class
*/
public static Class defineClass(String className, byte[] classData, ClassLoader classLoader) {
try {
return (Class) ReflectUtil.invokeDeclared(ClassLoader.class, classLoader, "defineClass",
new Class[] {String.class, byte[].class, int.class, int.class},
new Object[] {className, classData, Integer.valueOf(0), Integer.valueOf(classData.length)});
} catch (Throwable th) {
throw new RuntimeException("Define class failed: " + className, th);
}
}
// ---------------------------------------------------------------- find class
/**
* @see #findClass(String, java.net.URL[], ClassLoader)
*/
public static Class findClass(String className, File[] classPath, ClassLoader parent) {
URL[] urls = new URL[classPath.length];
for (int i = 0; i < classPath.length; i++) {
File file = classPath[i];
try {
urls[i] = FileUtil.toURL(file);
} catch (MalformedURLException ignore) {
}
}
return findClass(className, urls, parent);
}
/**
* Finds and loads class on classpath even if it was already loaded.
* @param className class name to find
* @param classPath classpath
* @param parent optional parent class loader, may be null
*/
public static Class findClass(String className, URL[] classPath, ClassLoader parent) {
URLClassLoader tempClassLoader = parent != null ? new URLClassLoader(classPath, parent) : new URLClassLoader(classPath);
try {
return (Class) ReflectUtil.invokeDeclared(URLClassLoader.class, tempClassLoader, "findClass",
new Class[] {String.class},
new Object[] {className});
} catch (Throwable th) {
throw new RuntimeException("Class not found: " + className, th);
}
}
// ---------------------------------------------------------------- classpath
private static final String[] MANIFESTS = {"Manifest.mf", "manifest.mf", "MANIFEST.MF"};
/**
* Finds tools.jar. Returns null if does not exist.
*/
public static File findToolsJar() {
String javaHome = SystemUtil.javaHome();
if (javaHome == null) {
return null;
}
String tools = new File(javaHome).getAbsolutePath() + File.separatorChar + "lib" + File.separatorChar + "tools.jar";
File toolsFile = new File(tools);
if (toolsFile.exists()) {
return toolsFile;
}
return null;
}
/**
* Returns classpath item manifest or null if not found.
*/
public static Manifest getClasspathItemManifest(File classpathItem) {
Manifest manifest = null;
if (classpathItem.isFile()) {
FileInputStream fis = null;
try {
fis = new FileInputStream(classpathItem);
JarFile jar = new JarFile(classpathItem);
manifest = jar.getManifest();
} catch (IOException ignore) {
}
finally {
StreamUtil.close(fis);
}
} else {
File metaDir = new File(classpathItem, "META-INF");
File manifestFile = null;
if (metaDir.isDirectory()) {
for (String m : MANIFESTS) {
File mFile = new File(metaDir, m);
if (mFile.isFile()) {
manifestFile = mFile;
break;
}
}
}
if (manifestFile != null) {
FileInputStream fis = null;
try {
fis = new FileInputStream(manifestFile);
manifest = new Manifest(fis);
} catch (IOException ignore) {
}
finally {
StreamUtil.close(fis);
}
}
}
return manifest;
}
/**
* Returns base folder for classpath item. If item is a (jar) file,
* its parent is returned. If item is a directory, its name is returned.
*/
public static String getClasspathItemBaseDir(File classpathItem) {
String base;
if (classpathItem.isFile()) {
base = classpathItem.getParent();
} else {
base = classpathItem.toString();
}
return base;
}
/**
* Returns default classpath using
* {@link #getDefaultClassLoader() default classloader}.
*/
public static File[] getDefaultClasspath() {
return getDefaultClasspath(getDefaultClassLoader());
}
/**
* Returns default class path from all available URLClassLoader
* in classloader hierarchy. The following is added to the classpath list:
*
* - file URLs from
URLClassLoader (other URL protocols are ignored)
* - inner entries from containing manifest files (if exist)
* - bootstrap classpath
*
*/
public static File[] getDefaultClasspath(ClassLoader classLoader) {
Set classpaths = new TreeSet<>();
while (classLoader != null) {
if (classLoader instanceof URLClassLoader) {
URL[] urls = ((URLClassLoader) classLoader).getURLs();
for (URL u : urls) {
File f = FileUtil.toFile(u);
if ((f != null) && f.exists()) {
try {
f = f.getCanonicalFile();
boolean newElement = classpaths.add(f);
if (newElement) {
addInnerClasspathItems(classpaths, f);
}
} catch (IOException ignore) {
}
}
}
}
classLoader = classLoader.getParent();
}
String bootstrap = SystemUtil.getSunBoothClassPath();
if (bootstrap != null) {
String[] bootstrapFiles = StringUtil.splitc(bootstrap, File.pathSeparatorChar);
for (String bootstrapFile: bootstrapFiles) {
File f = new File(bootstrapFile);
if (f.exists()) {
try {
f = f.getCanonicalFile();
boolean newElement = classpaths.add(f);
if (newElement) {
addInnerClasspathItems(classpaths, f);
}
} catch (IOException ignore) {
}
}
}
}
File[] result = new File[classpaths.size()];
return classpaths.toArray(result);
}
private static void addInnerClasspathItems(Set classpaths, File item) {
Manifest manifest = getClasspathItemManifest(item);
if (manifest == null) {
return;
}
Attributes attributes = manifest.getMainAttributes();
if (attributes == null) {
return;
}
String s = attributes.getValue(Attributes.Name.CLASS_PATH);
if (s == null) {
return;
}
String base = getClasspathItemBaseDir(item);
String[] tokens = StringUtil.splitc(s, ' ');
for (String t : tokens) {
File file;
// try file with the base path
try {
file = new File(base, t);
file = file.getCanonicalFile();
if (!file.exists()) {
file = null;
}
} catch (Exception ignore) {
file = null;
}
if (file == null) {
// try file with absolute path
try {
file = new File(t);
file = file.getCanonicalFile();
if (!file.exists()) {
file = null;
}
} catch (Exception ignore) {
file = null;
}
}
if (file == null) {
// try the URL
try {
URL url = new URL(t);
file = new File(url.getFile());
file = file.getCanonicalFile();
if (!file.exists()) {
file = null;
}
} catch (Exception ignore) {
file = null;
}
}
if (file != null && file.exists()) {
classpaths.add(file);
}
}
}
// ---------------------------------------------------------------- get resource
/**
* Retrieves given resource as URL.
* @see #getResourceUrl(String, ClassLoader)
*/
public static URL getResourceUrl(String resourceName) {
return getResourceUrl(resourceName, null);
}
/**
* Retrieves given resource as URL. Resource is always absolute and may
* starts with a slash character.
*
* Resource will be loaded using class loaders in the following order:
*
* - {@link Thread#getContextClassLoader() Thread.currentThread().getContextClassLoader()}
* - {@link Class#getClassLoader() ClassLoaderUtil.class.getClassLoader()}
* - if
callingClass is provided: {@link Class#getClassLoader() callingClass.getClassLoader()}
*
*/
public static URL getResourceUrl(String resourceName, ClassLoader classLoader) {
if (resourceName.startsWith("/")) {
resourceName = resourceName.substring(1);
}
URL resourceUrl;
// try #1 - using provided class loader
if (classLoader != null) {
resourceUrl = classLoader.getResource(resourceName);
if (resourceUrl != null) {
return resourceUrl;
}
}
// try #2 - using thread class loader
ClassLoader currentThreadClassLoader = Thread.currentThread().getContextClassLoader();
if ((currentThreadClassLoader != null) && (currentThreadClassLoader != classLoader)) {
resourceUrl = currentThreadClassLoader.getResource(resourceName);
if (resourceUrl != null) {
return resourceUrl;
}
}
// try #3 - using caller classloader, similar as Class.forName()
Class callerClass = ReflectUtil.getCallerClass(2);
ClassLoader callerClassLoader = callerClass.getClassLoader();
if ((callerClassLoader != classLoader) && (callerClassLoader != currentThreadClassLoader)) {
resourceUrl = callerClassLoader.getResource(resourceName);
if (resourceUrl != null) {
return resourceUrl;
}
}
return null;
}
// ---------------------------------------------------------------- get resource file
/**
* Retrieves resource as file.
* @see #getResourceFile(String)
*/
public static File getResourceFile(String resourceName) {
return getResourceFile(resourceName, null);
}
/**
* Retrieves resource as file. Resource is retrieved as {@link #getResourceUrl(String, ClassLoader) URL},
* than it is converted to URI so it can be used by File constructor.
*/
public static File getResourceFile(String resourceName, ClassLoader classLoader) {
try {
URL resourceUrl = getResourceUrl(resourceName, classLoader);
if (resourceUrl == null) {
return null;
}
return new File(resourceUrl.toURI());
} catch (URISyntaxException ignore) {
return null;
}
}
// ---------------------------------------------------------------- get resource stream
/**
* Opens a resource of the specified name for reading.
* @see #getResourceAsStream(String, ClassLoader)
*/
public static InputStream getResourceAsStream(String resourceName) throws IOException {
return getResourceAsStream(resourceName, null);
}
/**
* Opens a resource of the specified name for reading.
* @see #getResourceAsStream(String, ClassLoader, boolean)
*/
public static InputStream getResourceAsStream(String resourceName, boolean useCache) throws IOException {
return getResourceAsStream(resourceName, null, useCache);
}
/**
* Opens a resource of the specified name for reading.
* @see #getResourceUrl(String, ClassLoader)
*/
public static InputStream getResourceAsStream(String resourceName, ClassLoader callingClass) throws IOException {
URL url = getResourceUrl(resourceName, callingClass);
if (url != null) {
return url.openStream();
}
return null;
}
/**
* Opens a resource of the specified name for reading. Controls caching,
* that is important when the same jar is reloaded using custom classloader.
*/
public static InputStream getResourceAsStream(String resourceName, ClassLoader callingClass, boolean useCache) throws IOException {
URL url = getResourceUrl(resourceName, callingClass);
if (url != null) {
URLConnection urlConnection = url.openConnection();
urlConnection.setUseCaches(useCache);
return urlConnection.getInputStream();
}
return null;
}
/**
* Opens a class of the specified name for reading using class classloader.
* @see #getResourceAsStream(String, ClassLoader)
*/
public static InputStream getClassAsStream(Class clazz) throws IOException {
return getResourceAsStream(getClassFileName(clazz), clazz.getClassLoader());
}
/**
* Opens a class of the specified name for reading. No specific classloader is used
* for loading class.
* @see #getResourceAsStream(String, ClassLoader)
*/
public static InputStream getClassAsStream(String className) throws IOException {
return getResourceAsStream(getClassFileName(className));
}
/**
* Opens a class of the specified name for reading using provided class loader.
*/
public static InputStream getClassAsStream(String className, ClassLoader classLoader) throws IOException {
return getResourceAsStream(getClassFileName(className), classLoader);
}
// ---------------------------------------------------------------- load class
/**
* Loads a class using default class loader strategy.
* @see jodd.util.cl.DefaultClassLoaderStrategy
*/
public static Class loadClass(String className) throws ClassNotFoundException {
return JoddCore.classLoaderStrategy.loadClass(className, null);
}
/**
* Loads a class using default class loader strategy.
* @see jodd.util.cl.DefaultClassLoaderStrategy
*/
public static Class loadClass(String className, ClassLoader classLoader) throws ClassNotFoundException {
return JoddCore.classLoaderStrategy.loadClass(className, classLoader);
}
// ---------------------------------------------------------------- misc
/**
* Resolves class file name from class name by replacing dot's with '/' separator
* and adding class extension at the end. If array, component type is returned.
*/
public static String getClassFileName(Class clazz) {
if (clazz.isArray()) {
clazz = clazz.getComponentType();
}
return getClassFileName(clazz.getName());
}
/**
* Resolves class file name from class name by replacing dot's with '/' separator.
*/
public static String getClassFileName(String className) {
return className.replace('.', '/') + ".class";
}
}
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