Java tutorial
/** * wiki-tools-lucene-hadoop: Java tools for searching Wikipedia Lucene indexes in HDFS * * 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 cc.wikitools.lucene.hadoop; import java.io.PrintStream; 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.Configured; import org.apache.hadoop.fs.Path; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; public class ScoreWikipediaArticleHdfs extends Configured implements Tool { private static final String INDEX_OPTION = "index"; private static final String ID_OPTION = "id"; private static final String TITLE_OPTION = "title"; private static final String QUERY_OPTION = "q"; @SuppressWarnings("static-access") @Override public int run(String[] args) throws Exception { Options options = new Options(); options.addOption( OptionBuilder.withArgName("path").hasArg().withDescription("index location").create(INDEX_OPTION)); options.addOption(OptionBuilder.withArgName("num").hasArg().withDescription("id").create(ID_OPTION)); options.addOption( OptionBuilder.withArgName("string").hasArg().withDescription("title").create(TITLE_OPTION)); options.addOption( OptionBuilder.withArgName("string").hasArg().withDescription("query text").create(QUERY_OPTION)); CommandLine cmdline = null; CommandLineParser parser = new GnuParser(); try { cmdline = parser.parse(options, args); } catch (ParseException exp) { System.err.println("Error parsing command line: " + exp.getMessage()); System.exit(-1); } if (!(cmdline.hasOption(ID_OPTION) || cmdline.hasOption(TITLE_OPTION)) || !cmdline.hasOption(INDEX_OPTION) || !cmdline.hasOption(QUERY_OPTION)) { HelpFormatter formatter = new HelpFormatter(); formatter.printHelp(ScoreWikipediaArticleHdfs.class.getName(), options); System.exit(-1); } String indexLocation = cmdline.getOptionValue(INDEX_OPTION); String queryText = cmdline.getOptionValue(QUERY_OPTION); HdfsWikipediaSearcher searcher = new HdfsWikipediaSearcher(new Path(indexLocation), getConf()); PrintStream out = new PrintStream(System.out, true, "UTF-8"); if (cmdline.hasOption(ID_OPTION)) { out.println("score: " + searcher.scoreArticle(queryText, Integer.parseInt(cmdline.getOptionValue(ID_OPTION)))); } else { out.println("score: " + searcher.scoreArticle(queryText, cmdline.getOptionValue(TITLE_OPTION))); } searcher.close(); out.close(); return 0; } public static void main(String[] args) throws Exception { ToolRunner.run(new ScoreWikipediaArticleHdfs(), args); } }