org.apache.tools.ant.util.LoaderUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tools.ant.util;
import java.io.File;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.launch.Locator;
// CheckStyle:HideUtilityClassConstructorCheck OFF - bc
/**
* ClassLoader utility methods
*
*/
public class LoaderUtils {
/** Utilities used for file operations */
private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();
/**
* Set the context classloader
*
* @param loader the ClassLoader to be used as the context class loader
* on the current thread.
*/
public static void setContextClassLoader(ClassLoader loader) {
Thread currentThread = Thread.currentThread();
currentThread.setContextClassLoader(loader);
}
/**
* JDK1.1 compatible access to set the context class loader.
*
* @return the ClassLoader instance being used as the context
* classloader on the current thread. Returns null on JDK 1.1
*/
public static ClassLoader getContextClassLoader() {
Thread currentThread = Thread.currentThread();
return currentThread.getContextClassLoader();
}
/**
* Indicates if the context class loader methods are available
*
* @return true if the get and set methods dealing with the context
* classloader are available.
*/
public static boolean isContextLoaderAvailable() {
return true;
}
/**
* Normalize a source location
*
* @param source the source location to be normalized.
*
* @return the normalized source location.
*/
private static File normalizeSource(File source) {
if (source != null) {
try {
source = FILE_UTILS.normalize(source.getAbsolutePath());
} catch (BuildException e) {
// relative path
}
}
return source;
}
/**
* Find the directory or jar file the class has been loaded from.
*
* @param c the class whose location is required.
* @return the file or jar with the class or null if we cannot
* determine the location.
*
* @since Ant 1.6
*/
public static File getClassSource(Class c) {
return normalizeSource(Locator.getClassSource(c));
}
/**
* Find the directory or a give resource has been loaded from.
*
* @param c the classloader to be consulted for the source
* @param resource the resource whose location is required.
*
* @return the file with the resource source or null if
* we cannot determine the location.
*
* @since Ant 1.6
*/
public static File getResourceSource(ClassLoader c, String resource) {
if (c == null) {
c = LoaderUtils.class.getClassLoader();
}
return normalizeSource(Locator.getResourceSource(c, resource));
}
/**
* Return the resource name of a class name.
* @param className the name of the class to convert.
* @return the corresponding resource name.
* @since Ant 1.7.0.
*/
public static String classNameToResource(String className) {
return className.replace('.', '/') + ".class";
}
/**
* Check if a classloader has a classname resource.
* @param loader the classloader to look it.
* @param className the name of the class to look for.
* @return true if the classexists, false otherwise
* @since Ant 1.7.0.
*/
public static boolean classExists(ClassLoader loader, String className) {
return loader.getResource(classNameToResource(className)) != null;
}
}