org.apache.hadoop.util.ClassUtil 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.hadoop.util;
import java.io.IOException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Enumeration;
import org.apache.hadoop.classification.InterfaceAudience;
@InterfaceAudience.Private
public class ClassUtil {
/**
* Find a jar that contains a class of the same name, if any.
* It will return a jar file, even if that is not the first thing
* on the class path that has a class with the same name.
*
* @param clazz the class to find.
* @return a jar file that contains the class, or null.
*/
public static String findContainingJar(Class clazz) {
ClassLoader loader = clazz.getClassLoader();
String classFile = clazz.getName().replaceAll("\\.", "/") + ".class";
try {
for(final Enumeration itr = loader.getResources(classFile);
itr.hasMoreElements();) {
final URL url = itr.nextElement();
if ("jar".equals(url.getProtocol())) {
String toReturn = url.getPath();
if (toReturn.startsWith("file:")) {
toReturn = toReturn.substring("file:".length());
}
toReturn = URLDecoder.decode(toReturn, "UTF-8");
return toReturn.replaceAll("!.*$", "");
}
}
} catch (IOException e) {
throw new RuntimeException(e);
}
return null;
}
}