Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 gov.nasa.jpl.memex.pooledtimeseries; import java.io.IOException; import java.util.*; import java.io.*; import org.apache.commons.codec.digest.DigestUtils; import org.apache.hadoop.fs.Path; import org.apache.hadoop.conf.*; import org.apache.hadoop.io.*; import org.apache.hadoop.mapreduce.*; import org.apache.hadoop.util.*; import org.apache.hadoop.util.*; import org.apache.hadoop.mapred.lib.*; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.Mapper; import org.apache.hadoop.mapreduce.Reducer; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.TextInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import org.opencv.core.Core; import org.opencv.core.Mat; import org.opencv.core.MatOfPoint2f; import org.opencv.core.Point; import org.opencv.core.Size; import org.opencv.highgui.VideoCapture; import org.opencv.imgproc.Imgproc; import org.opencv.video.Video; public class SimilarityCalculation { public static class Map extends Mapper<LongWritable, Text, Text, Text> { public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException, NumberFormatException { System.out.println(value.toString()); Configuration conf = context.getConfiguration(); String meanDistsPath = conf.get("meanDistsFilePath"); String[] videoPaths = value.toString().split(","); ArrayList<double[]> tws = PoT.getTemporalWindows(4); ArrayList<FeatureVector> fvList = new ArrayList<FeatureVector>(); for (String video : videoPaths) { ArrayList<double[][]> multiSeries = new ArrayList<double[][]>(); String ofCachePath = video + ".of.txt"; String hogCachePath = video + ".hog.txt"; double[][] series1 = PoT.loadTimeSeries(new File(ofCachePath).toPath()); double[][] series2 = PoT.loadTimeSeries(new File(hogCachePath).toPath()); multiSeries.add(series1); multiSeries.add(series2); FeatureVector fv = new FeatureVector(); for (int i = 0; i < multiSeries.size(); i++) { fv.feature.add(PoT.computeFeaturesFromSeries(multiSeries.get(i), tws, 1)); fv.feature.add(PoT.computeFeaturesFromSeries(multiSeries.get(i), tws, 2)); fv.feature.add(PoT.computeFeaturesFromSeries(multiSeries.get(i), tws, 5)); } fvList.add(fv); } double[] meanDists = new double[fvList.get(0).numDim()]; BufferedReader inFile = new BufferedReader(new FileReader(meanDistsPath)); String line; int counter = 0; while ((line = inFile.readLine()) != null) { meanDists[counter] = Double.parseDouble(line); counter++; } double similarity = PoT.kernelDistance(fvList.get(0), fvList.get(1), meanDists); File p1 = new File(videoPaths[0]); File p2 = new File(videoPaths[1]); context.write(new Text(p1.getName() + ',' + p2.getName()), new Text(String.valueOf(similarity))); } } public static void main(String[] args) throws Exception { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); Configuration baseConf = new Configuration(); baseConf.set("mapred.reduce.tasks", "0"); baseConf.set("meanDistsFilePath", args[2]); Job job = Job.getInstance(baseConf); job.setJarByClass(SimilarityCalculation.class); job.setJobName("similarity_calc"); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); job.setInputFormatClass(TextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); FileInputFormat.setInputPaths(job, new Path(args[0])); FileOutputFormat.setOutputPath(job, new Path(args[1])); job.setMapperClass(Map.class); job.waitForCompletion(true); } }