/*
* Cloud9: A MapReduce Library for Hadoop
*
* Licensed 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 edu.umd.cloud9.example.hbase;
import java.util.Arrays;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;
/**
* Simple demo of HBase; fetching word counts.
*
* @author Jimmy Lin
*/
public class HBaseWordCountFetch extends Configured implements Tool {
private static final Logger LOG = Logger.getLogger(HBaseWordCountFetch.class);
/**
* Creates an instance of this tool.
*/
public HBaseWordCountFetch() {}
private static final String TABLE = "table";
private static final String WORD = "word";
/**
* Runs this tool.
*/
@SuppressWarnings({ "static-access" })
public int run(String[] args) throws Exception {
Options options = new Options();
options.addOption(OptionBuilder.withArgName("table").hasArg()
.withDescription("HBase table name").create(TABLE));
options.addOption(OptionBuilder.withArgName("word").hasArg()
.withDescription("word to look up").create(WORD));
CommandLine cmdline;
CommandLineParser parser = new GnuParser();
try {
cmdline = parser.parse(options, args);
} catch (ParseException exp) {
System.err.println("Error parsing command line: " + exp.getMessage());
return -1;
}
if (!cmdline.hasOption(TABLE) || !cmdline.hasOption(WORD)) {
System.out.println("args: " + Arrays.toString(args));
HelpFormatter formatter = new HelpFormatter();
formatter.setWidth(120);
formatter.printHelp(this.getClass().getName(), options);
ToolRunner.printGenericCommandUsage(System.out);
return -1;
}
String tableName = cmdline.getOptionValue(TABLE);
String word = cmdline.getOptionValue(WORD);
Configuration conf = getConf();
conf.addResource(new Path("/etc/hbase/conf/hbase-site.xml"));
Configuration hbaseConfig = HBaseConfiguration.create(conf);
HConnection hbaseConnection = HConnectionManager.createConnection(hbaseConfig);
HTableInterface table = hbaseConnection.getTable(tableName);
Get get = new Get(Bytes.toBytes(word));
Result result = table.get(get);
int count = Bytes.toInt(result.getValue(HBaseWordCount.CF, HBaseWordCount.COUNT));
LOG.info("word: " + word + ", count: " + count);
return 0;
}
/**
* Dispatches command-line arguments to the tool via the {@code ToolRunner}.
*/
public static void main(String[] args) throws Exception {
ToolRunner.run(new HBaseWordCountFetch(), args);
}
}