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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with this
4    * work for additional information regarding copyright ownership. The ASF
5    * licenses this file to you under the Apache License, Version 2.0 (the
6    * "License"); you may not use this file except in compliance with the License.
7    * You may obtain a copy of the License at
8    *
9    * http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14   * License for the specific language governing permissions and limitations
15   * under the License.
16   */
17  package org.apache.hadoop.hbase.util;
18  
19  import java.util.Set;
20  import java.util.TreeSet;
21  
22  import org.apache.commons.cli.BasicParser;
23  import org.apache.commons.cli.CommandLine;
24  import org.apache.commons.cli.CommandLineParser;
25  import org.apache.commons.cli.HelpFormatter;
26  import org.apache.commons.cli.Options;
27  import org.apache.commons.cli.ParseException;
28  import org.apache.commons.logging.Log;
29  import org.apache.commons.logging.LogFactory;
30  import org.apache.hadoop.classification.InterfaceAudience;
31  import org.apache.hadoop.conf.Configuration;
32  import org.apache.hadoop.hbase.HBaseConfiguration;
33  import org.apache.hadoop.util.Tool;
34  import org.apache.hadoop.util.ToolRunner;
35  
36  /**
37   * Common base class used for HBase command-line tools. Simplifies workflow and
38   * command-line argument parsing.
39   */
40  @InterfaceAudience.Private
41  public abstract class AbstractHBaseTool implements Tool {
42  
43    private static final int EXIT_SUCCESS = 0;
44    private static final int EXIT_FAILURE = 1;
45  
46    private static final String HELP_OPTION = "help";
47  
48    private static final Log LOG = LogFactory.getLog(AbstractHBaseTool.class);
49  
50    private final Options options = new Options();
51  
52    protected Configuration conf = null;
53  
54    private static final Set<String> requiredOptions = new TreeSet<String>();
55  
56    /**
57     * Override this to add command-line options using {@link #addOptWithArg}
58     * and similar methods.
59     */
60    protected abstract void addOptions();
61  
62    /**
63     * This method is called to process the options after they have been parsed.
64     */
65    protected abstract void processOptions(CommandLine cmd);
66  
67    /** The "main function" of the tool */
68    protected abstract int doWork() throws Exception;
69  
70    @Override
71    public Configuration getConf() {
72      return conf;
73    }
74  
75    @Override
76    public void setConf(Configuration conf) {
77      this.conf = conf;
78    }
79  
80    @Override
81    public final int run(String[] args) throws Exception {
82      if (conf == null) {
83        LOG.error("Tool configuration is not initialized");
84        throw new NullPointerException("conf");
85      }
86  
87      CommandLine cmd;
88      try {
89        // parse the command line arguments
90        cmd = parseArgs(args);
91      } catch (ParseException e) {
92        LOG.error("Error when parsing command-line arguemnts", e);
93        printUsage();
94        return EXIT_FAILURE;
95      }
96  
97      if (cmd.hasOption(HELP_OPTION) || !sanityCheckOptions(cmd)) {
98        printUsage();
99        return EXIT_FAILURE;
100     }
101 
102     processOptions(cmd);
103 
104     int ret = EXIT_FAILURE;
105     try {
106       ret = doWork();
107     } catch (Exception e) {
108       LOG.error("Error running command-line tool", e);
109       return EXIT_FAILURE;
110     }
111     return ret;
112   }
113 
114   private boolean sanityCheckOptions(CommandLine cmd) {
115     boolean success = true;
116     for (String reqOpt : requiredOptions) {
117       if (!cmd.hasOption(reqOpt)) {
118         LOG.error("Required option -" + reqOpt + " is missing");
119         success = false;
120       }
121     }
122     return success;
123   }
124 
125   private CommandLine parseArgs(String[] args) throws ParseException {
126     options.addOption(HELP_OPTION, false, "Show usage");
127     addOptions();
128     CommandLineParser parser = new BasicParser();
129     return parser.parse(options, args);
130   }
131 
132   private void printUsage() {
133     HelpFormatter helpFormatter = new HelpFormatter();
134     helpFormatter.setWidth(80);
135     String usageHeader = "Options:";
136     String usageFooter = "";
137     String usageStr = "bin/hbase " + getClass().getName() + " <options>";
138 
139     helpFormatter.printHelp(usageStr, usageHeader, options,
140         usageFooter);
141   }
142 
143   protected void addRequiredOptWithArg(String opt, String description) {
144     requiredOptions.add(opt);
145     addOptWithArg(opt, description);
146   }
147 
148   protected void addOptNoArg(String opt, String description) {
149     options.addOption(opt, false, description);
150   }
151 
152   protected void addOptWithArg(String opt, String description) {
153     options.addOption(opt, true, description);
154   }
155 
156   /**
157    * Parse a number and enforce a range.
158    */
159   public static long parseLong(String s, long minValue, long maxValue) {
160     long l = Long.parseLong(s);
161     if (l < minValue || l > maxValue) {
162       throw new IllegalArgumentException("The value " + l
163           + " is out of range [" + minValue + ", " + maxValue + "]");
164     }
165     return l;
166   }
167 
168   public static int parseInt(String s, int minValue, int maxValue) {
169     return (int) parseLong(s, minValue, maxValue);
170   }
171 
172   /** Call this from the concrete tool class's main function. */
173   protected void doStaticMain(String args[]) {
174     int ret;
175     try {
176       ret = ToolRunner.run(HBaseConfiguration.create(), this, args);
177     } catch (Exception ex) {
178       LOG.error("Error running command-line tool", ex);
179       ret = EXIT_FAILURE;
180     }
181     System.exit(ret);
182   }
183 
184 }