Java tutorial
/* * Cloud9: A Hadoop toolkit for working with big data * * 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.pagerank; import java.io.IOException; import java.util.Arrays; import java.util.Iterator; 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.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.Mapper; import org.apache.hadoop.mapreduce.Partitioner; import org.apache.hadoop.mapreduce.Reducer; import org.apache.hadoop.mapreduce.Reducer.Context; 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.SequenceFileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.apache.log4j.Logger; import edu.umd.cloud9.io.array.ArrayListOfIntsWritable; import edu.umd.cloud9.io.array.ArrayListWritable; import edu.umd.cloud9.io.map.String2IntOpenHashMapWritable; import edu.umd.cloud9.io.pair.PairOfFloats; import edu.umd.cloud9.io.pair.PairOfIntString; import edu.umd.cloud9.io.pair.PairOfStrings; //import pagerank.PageRankNodeMultiSrc; //import pagerank.PageRankNodeMultiSrc; /** * <p> * Driver program that takes a plain-text encoding of a directed graph and builds corresponding * Hadoop structures for representing the graph. * </p> * */ public class RecordExtracting extends Configured implements Tool { private static final Logger LOG = Logger.getLogger(RecordExtracting.class); //private static final String NODE_CNT_FIELD = "node.cnt"; private static final String NODE_SRC = "spamming users"; private static class MyMapper extends Mapper<LongWritable, Text, PairOfStrings, Text> { private static final IntWritable nid = new IntWritable(); //private static final PageRankNodeMultiSrc node = new PageRankNodeMultiSrc(); private static String SrcNode; private static int[] src; private static final String2IntOpenHashMapWritable MAP = new String2IntOpenHashMapWritable(); private static final PairOfStrings UIDPID = new PairOfStrings(); private static final Text RateComment = new Text(); @Override public void setup(Mapper<LongWritable, Text, PairOfStrings, Text>.Context context) { //int n = context.getConfiguration().getInt(NODE_CNT_FIELD, 0); SrcNode = context.getConfiguration().get(NODE_SRC); String[] sources = SrcNode.split(","); MAP.clear(); for (int i = 0; i < sources.length; i++) { MAP.put(sources[i], 1); } } @Override public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { String line = value.toString(); String[] terms = line.split("\t"); if (terms.length > 7) { String uid = terms[0].trim(); String pid = terms[1].trim(); int rate = Integer.parseInt(terms[5].trim().substring(0, 1)); String comment = rate + "\n" + terms[6] + " " + terms[7] + "\n"; //if the ID exists on the list then emit; if (MAP.containsKey(terms[0])) { UIDPID.set(uid, pid); RateComment.set(comment); context.write(UIDPID, RateComment); } } } } protected static class MyPartitioner extends Partitioner<PairOfStrings, Text> { @Override public int getPartition(PairOfStrings key, Text value, int numReduceTasks) { return (key.getLeftElement().hashCode() & Integer.MAX_VALUE) % numReduceTasks; } } private static class MyReducer extends Reducer<PairOfStrings, Text, PairOfStrings, Text> { // Reuse objects. private final static PairOfIntString RID = new PairOfIntString(); //private final static ArrayListWritable<Text> List = new ArrayListWritable<Text> (); private final static Text first = new Text(); @Override public void reduce(PairOfStrings key, Iterable<Text> values, Context context) throws IOException, InterruptedException { // Sum up values. //List.clear(); String comments = new String(); Iterator<Text> iter = values.iterator(); int counter = 0; if (iter.hasNext()) { comments = iter.next().toString(); //buffer the first value of the current PID UID pairs counter++; } while (iter.hasNext()) // if there are additional comments, start emit these key-value pair { comments = comments + iter.next().toString(); counter++; } if (counter > 1) { //List.add(first); first.set(comments); //key.set(" ", " "); context.write(key, first); } } } public RecordExtracting() { } //private static final String INPUT = "input"; //private static final String OUTPUT = "output"; //private static final String NUM_NODES = "numNodes"; private static final String SOURCES = "sources"; private static final String NUM_REDUCERS = "numReducers"; /** * Runs this tool. */ @SuppressWarnings({ "static-access" }) public int run(String[] args) throws Exception { Options options = new Options(); /* options.addOption(OptionBuilder.withArgName("path").hasArg() .withDescription("input path").create(INPUT)); options.addOption(OptionBuilder.withArgName("path").hasArg() .withDescription("output path").create(OUTPUT)); options.addOption(OptionBuilder.withArgName("num").hasArg() .withDescription("number of nodes").create(NUM_NODES)); //parsing more than 1 integer later;*/ options.addOption( OptionBuilder.withArgName("src").hasArg().withDescription("spamming users").create(SOURCES)); options.addOption(OptionBuilder.withArgName("num").hasArg().withDescription("number of reducers") .create(NUM_REDUCERS)); 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(INPUT) || !cmdline.hasOption(OUTPUT) || !cmdline.hasOption(NUM_NODES)||!cmdline.hasOption(SOURCES)) { 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 inputPath = "xzzqskfinal/reviewsNew.txt";//cmdline.getOptionValue(INPUT); String outputPath = "xzzqskfinal/SpammingRecord";//cmdline.getOptionValue(OUTPUT); //int n = Integer.parseInt(cmdline.getOptionValue(NUM_NODES)); //Change to array later String src = cmdline.getOptionValue(SOURCES); int reduceTasks = cmdline.hasOption(NUM_REDUCERS) ? Integer.parseInt(cmdline.getOptionValue(NUM_REDUCERS)) : 1; LOG.info("Tool name: " + RecordExtracting.class.getSimpleName()); LOG.info(" - inputDir: " + inputPath); LOG.info(" - outputDir: " + outputPath); //LOG.info(" - numNodes: " + n); Configuration conf = getConf(); conf.set("mapreduce.map.memory.mb", "2048"); conf.set("mapreduce.map.java.opts", "-Xmx2048m"); conf.set("mapreduce.reduce.memory.mb", "2048"); conf.set("mapreduce.reduce.java.opts", "-Xmx2048m"); //conf.setInt(NODE_CNT_FIELD, n); //more to be set later; conf.set(NODE_SRC, src); conf.setInt("mapred.min.split.size", 1024 * 1024 * 1024); Job job = Job.getInstance(conf); job.setJobName(RatingSpamming.class.getSimpleName()); job.setJarByClass(RecordExtracting.class); job.setNumReduceTasks(reduceTasks); FileInputFormat.addInputPath(job, new Path(inputPath)); FileOutputFormat.setOutputPath(job, new Path(outputPath)); job.setInputFormatClass(TextInputFormat.class); //job.setOutputFormatClass(TextOutputFormat.class); //job.setOutputFormatClass(SequenceFileOutputFormat.class); job.setMapOutputKeyClass(PairOfStrings.class); job.setMapOutputValueClass(Text.class); job.setOutputKeyClass(PairOfStrings.class); job.setOutputValueClass(Text.class); job.setMapperClass(MyMapper.class); job.setReducerClass(MyReducer.class); // Delete the output directory if it exists already. FileSystem.get(conf).delete(new Path(outputPath), true); job.waitForCompletion(true); long startTime = System.currentTimeMillis(); job.waitForCompletion(true); LOG.info("Job Finished in " + (System.currentTimeMillis() - startTime) / 1000.0 + " seconds"); return 0; } /** * Dispatches command-line arguments to the tool via the {@code ToolRunner}. */ public static void main(String[] args) throws Exception { ToolRunner.run(new RecordExtracting(), args); } }