Java tutorial
/* * Copyright (C) liuchangyan@BUPT. 2009. * * 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 org.sf.xrime.algorithms.layout.radialtree; import java.io.IOException; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapred.FileInputFormat; import org.apache.hadoop.mapred.FileOutputFormat; import org.apache.hadoop.mapred.JobClient; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.SequenceFileInputFormat; import org.apache.hadoop.mapred.SequenceFileOutputFormat; import org.sf.xrime.ProcessorExecutionException; import org.sf.xrime.algorithms.GraphAlgorithm; import org.sf.xrime.model.vertex.LabeledAdjVertex; import org.sf.xrime.utils.SequenceTempDirMgr; /** * The first step of RadialTree Layout Algorithm. * @author liu chang yan */ public class RadialTreeStep1 extends GraphAlgorithm { private String continueFileName = "continue1"; static final public String continueFileKey = "xrime.algorithm.layout.radialtree.continue1.flag"; private boolean end = false; private JobConf jobConf; private FileSystem client = null; private SequenceTempDirMgr tempDirs = null; public String getContinueFlag() { return continueFileName; } public void setContinueFlag(String continueFlag) { this.continueFileName = continueFlag; } private String continueFlagFile() throws IllegalAccessException { Path filePath = new Path(context.getDestination().getPath().toString() + "/" + continueFileName); return filePath.toString(); } public boolean isEnd() { return end; } public FileSystem getClient() { return client; } public void setClient(FileSystem client) { this.client = client; } public SequenceTempDirMgr getTempDirs() { return tempDirs; } public void setTempDirs(SequenceTempDirMgr tempDirs) { this.tempDirs = tempDirs; } @Override public void execute() throws ProcessorExecutionException { try { context.setParameter(continueFileKey, continueFlagFile()); jobConf = new JobConf(context, RadialTreeStep1.class); jobConf.setJobName("RadialTreeVisit"); FileInputFormat.setInputPaths(jobConf, context.getSource().getPath()); // Using RadialTreeVisitMapper.class and RadialTreeVisitReducer.class to // visit all the graph and get the topoolgy. jobConf.setInputFormat(SequenceFileInputFormat.class); jobConf.setMapperClass(RadialTreeVisitMapper.class); jobConf.setNumMapTasks(getMapperNum()); jobConf.setMapOutputValueClass(LabeledAdjVertex.class); jobConf.setReducerClass(RadialTreeVisitReducer.class); jobConf.setNumReduceTasks(getReducerNum()); jobConf.setOutputKeyClass(Text.class); jobConf.setOutputValueClass(LabeledAdjVertex.class); FileOutputFormat.setOutputPath(jobConf, context.getDestination().getPath()); jobConf.setOutputFormat(SequenceFileOutputFormat.class); this.runningJob = JobClient.runJob(jobConf); if (client == null) { client = FileSystem.get(jobConf); } if (client.exists(new Path(continueFlagFile()))) { end = false; client.delete(new Path(continueFlagFile()), true); } else { end = true; } } catch (IOException e) { throw new ProcessorExecutionException(e); } catch (IllegalAccessException e) { e.printStackTrace(); } } }