| /** |
| * 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.util.jar.*; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| /** |
| * A micro-application that prints the main class name out of a jar file. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class PrintJarMainClass { |
| |
| /** |
| * @param args |
| */ |
| public static void main(String[] args) { |
| try { |
| JarFile jar_file = new JarFile(args[0]); |
| if (jar_file != null) { |
| Manifest manifest = jar_file.getManifest(); |
| if (manifest != null) { |
| String value = manifest.getMainAttributes().getValue("Main-Class"); |
| if (value != null) { |
| System.out.println(value.replaceAll("/", ".")); |
| return; |
| } |
| } |
| } |
| } catch (Throwable e) { |
| // ignore it |
| } |
| System.out.println("UNKNOWN"); |
| System.exit(1); |
| } |
| |
| } |