Java tutorial
/* * Copyright (C) IBM Corp. 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.gfr; import java.io.IOException; import org.apache.hadoop.io.DoubleWritable; 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.Mapper; import org.apache.hadoop.mapred.OutputCollector; import org.apache.hadoop.mapred.Reporter; 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.algorithms.layout.ConstantLabels; import org.sf.xrime.algorithms.utils.GraphAlgorithmMapReduceBase; import org.sf.xrime.model.vertex.LabeledAdjSetVertex; /** * This algorithm is used to adjust the coordinates of each vertex. Since we restrict all vertexes * within a frame smaller than the input frame, we need to adjust the layout output to make the * final layout center in the input frame. * @author xue * */ public class CoordinatesAdjust extends GraphAlgorithm { /** * Default constructor. */ public CoordinatesAdjust() { super(); } /** * Mapper. * @author xue */ public static class MapClass extends GraphAlgorithmMapReduceBase implements Mapper<Text, LabeledAdjSetVertex, Text, LabeledAdjSetVertex> { @Override public void map(Text key, LabeledAdjSetVertex value, OutputCollector<Text, LabeledAdjSetVertex> output, Reporter reporter) throws IOException { // Get displacements for x and y. int x_disp = Integer.parseInt(context.getParameter(ConstantLabels.X_DISP)); int y_disp = Integer.parseInt(context.getParameter(ConstantLabels.Y_DISP)); // Get the coordinates of this vertex. double x_coordinate = ((DoubleWritable) value.getLabel(ConstantLabels.X_COORDINATE)).get(); double y_coordinate = ((DoubleWritable) value.getLabel(ConstantLabels.Y_COORDINATE)).get(); x_coordinate += x_disp; y_coordinate += y_disp; // Update the coordinates. value.setLabel(ConstantLabels.X_COORDINATE, new DoubleWritable(x_coordinate)); value.setLabel(ConstantLabels.Y_COORDINATE, new DoubleWritable(y_coordinate)); output.collect(key, value); } } @Override public void execute() throws ProcessorExecutionException { JobConf conf = new JobConf(context, CoordinatesAdjust.class); conf.setJobName("CoordinatesAdjust"); conf.setOutputKeyClass(Text.class); conf.setOutputValueClass(LabeledAdjSetVertex.class); conf.setMapperClass(MapClass.class); // No combiner or reducer is needed.. // makes the file format suitable for machine processing. conf.setInputFormat(SequenceFileInputFormat.class); conf.setOutputFormat(SequenceFileOutputFormat.class); try { FileInputFormat.setInputPaths(conf, getSource().getPath()); FileOutputFormat.setOutputPath(conf, getDestination().getPath()); } catch (IllegalAccessException e1) { throw new ProcessorExecutionException(e1); } conf.setNumMapTasks(getMapperNum()); conf.setNumReduceTasks(0); try { this.runningJob = JobClient.runJob(conf); } catch (IOException e) { throw new ProcessorExecutionException(e); } } }