/** * 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.streaming; import java.util.Arrays; import org.apache.hadoop.util.ToolRunner; /** The main entry point. Usually invoked with the script * bin/hadoop jar hadoop-streaming.jar args. */ public class HadoopStreaming { public static void main(String[] args) throws Exception { if (args.length < 1) { System.err.println("No Arguments Given!"); printUsage(); System.exit(1); } int returnStatus = 0; String cmd = args[0]; String[] remainingArgs = Arrays.copyOfRange(args, 1, args.length); if (cmd.equalsIgnoreCase("dumptb")) { DumpTypedBytes dumptb = new DumpTypedBytes(); returnStatus = ToolRunner.run(dumptb, remainingArgs); } else if (cmd.equalsIgnoreCase("loadtb")) { LoadTypedBytes loadtb = new LoadTypedBytes(); returnStatus = ToolRunner.run(loadtb, remainingArgs); } else if (cmd.equalsIgnoreCase("streamjob")) { StreamJob job = new StreamJob(); returnStatus = ToolRunner.run(job, remainingArgs); } else { // for backward compatibility StreamJob job = new StreamJob(); returnStatus = ToolRunner.run(job, args); } if (returnStatus != 0) { System.err.println("Streaming Command Failed!"); System.exit(returnStatus); } } private static void printUsage() { System.out.println("Usage: $HADOOP_PREFIX/bin/hadoop jar hadoop-streaming.jar" + " [options]"); System.out.println("Options:"); System.out.println(" dumptb <glob-pattern> Dumps all files that match the" + " given pattern to "); System.out.println(" standard output as typed " + "bytes."); System.out.println(" loadtb <path> Reads typed bytes from standard input" + " and stores them in"); System.out.println(" a sequence file in the specified path"); System.out.println(" [streamjob] <args> Runs streaming job with given" + " arguments"); } }