| /** |
| * 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.io.PrintStream; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** |
| * A utility to help run {@link Tool}s. |
| * |
| * <p><code>ToolRunner</code> can be used to run classes implementing |
| * <code>Tool</code> interface. It works in conjunction with |
| * {@link GenericOptionsParser} to parse the |
| * <a href="{@docRoot}/org/apache/hadoop/util/GenericOptionsParser.html#GenericOptions"> |
| * generic hadoop command line arguments</a> and modifies the |
| * <code>Configuration</code> of the <code>Tool</code>. The |
| * application-specific options are passed along without being modified. |
| * </p> |
| * |
| * @see Tool |
| * @see GenericOptionsParser |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class ToolRunner { |
| |
| /** |
| * Runs the given <code>Tool</code> by {@link Tool#run(String[])}, after |
| * parsing with the given generic arguments. Uses the given |
| * <code>Configuration</code>, or builds one if null. |
| * |
| * Sets the <code>Tool</code>'s configuration with the possibly modified |
| * version of the <code>conf</code>. |
| * |
| * @param conf <code>Configuration</code> for the <code>Tool</code>. |
| * @param tool <code>Tool</code> to run. |
| * @param args command-line arguments to the tool. |
| * @return exit code of the {@link Tool#run(String[])} method. |
| */ |
| public static int run(Configuration conf, Tool tool, String[] args) |
| throws Exception{ |
| if(conf == null) { |
| conf = new Configuration(); |
| } |
| GenericOptionsParser parser = new GenericOptionsParser(conf, args); |
| //set the configuration back, so that Tool can configure itself |
| tool.setConf(conf); |
| |
| //get the args w/o generic hadoop args |
| String[] toolArgs = parser.getRemainingArgs(); |
| return tool.run(toolArgs); |
| } |
| |
| /** |
| * Runs the <code>Tool</code> with its <code>Configuration</code>. |
| * |
| * Equivalent to <code>run(tool.getConf(), tool, args)</code>. |
| * |
| * @param tool <code>Tool</code> to run. |
| * @param args command-line arguments to the tool. |
| * @return exit code of the {@link Tool#run(String[])} method. |
| */ |
| public static int run(Tool tool, String[] args) |
| throws Exception{ |
| return run(tool.getConf(), tool, args); |
| } |
| |
| /** |
| * Prints generic command-line argurments and usage information. |
| * |
| * @param out stream to write usage information to. |
| */ |
| public static void printGenericCommandUsage(PrintStream out) { |
| GenericOptionsParser.printGenericCommandUsage(out); |
| } |
| |
| |
| /** |
| * Print out a prompt to the user, and return true if the user |
| * responds with "y" or "yes". (case insensitive) |
| */ |
| public static boolean confirmPrompt(String prompt) throws IOException { |
| while (true) { |
| System.err.print(prompt + " (Y or N) "); |
| StringBuilder responseBuilder = new StringBuilder(); |
| while (true) { |
| int c = System.in.read(); |
| if (c == -1 || c == '\r' || c == '\n') { |
| break; |
| } |
| responseBuilder.append((char)c); |
| } |
| |
| String response = responseBuilder.toString(); |
| if (response.equalsIgnoreCase("y") || |
| response.equalsIgnoreCase("yes")) { |
| return true; |
| } else if (response.equalsIgnoreCase("n") || |
| response.equalsIgnoreCase("no")) { |
| return false; |
| } |
| System.err.println("Invalid input: " + response); |
| // else ask them again |
| } |
| } |
| } |