hadoop-矩阵相乘法（MapReduce学习）

列行相乘法：参见高度可伸缩的稀疏矩阵乘法_吴志川.pdf

package org.bigdata508.util;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
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.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.bigdata.util.HadoopCfg;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;

/*
 * 2016-5-8
 * @author:lixin
 * 求矩阵乘积
 * */
public class Matrix {
    
    public static int tFlag = 0;
    private static class MatrixMapper extends Mapper<LongWritable, Text, IntWritable, Text>{

        private static int columnN = 0;
        private static int rowM = 0;
        
        @Override
        protected void setup(Mapper<LongWritable, Text, IntWritable, Text>.Context context)
                throws IOException, InterruptedException {
            Configuration conf = HadoopCfg.getInstance();
            columnN = conf.getInt("columnN",0);
            rowM = conf.getInt("rowM",0);
        }
        
        
        @Override
        protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, IntWritable, Text>.Context context)
                throws IOException, InterruptedException {
            FileSplit fileSplit = (FileSplit) context.getInputSplit();
            String fileName = fileSplit.getPath().getName();
            String str = value.toString();
            String[] strs = str.split(",");
            int i = Integer.parseInt(strs[0]);
            String[] strs2 = strs[1].split("	");
            int j = Integer.parseInt(strs2[0]);
            int val = Integer.parseInt(strs2[1]);
            if (fileName.startsWith("M")) {
                    context.write(new IntWritable(j), new Text("M," + i
                            + "," + val + ""));
            } else {// fileName == N
                    context.write(new IntWritable(i), new Text("N," + j
                            + "," + val + ""));
            }
        }
    }
    
    private static class MatrixReducer extends Reducer<IntWritable, Text, Text, IntWritable> {
        private static int columnN = 0;
        private static int rowM = 0;
        
        @Override
        protected void setup(
                Reducer<IntWritable, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException {
            Configuration conf = context.getConfiguration();
            columnN = conf.getInt("columnN",0);
            rowM = conf.getInt("rowM",0);
        }
        
        @Override
        protected void reduce(IntWritable key, Iterable<Text> values, Reducer<IntWritable, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException {
            int[] mArray = new int[rowM + 1];
            int[] nArray = new int[columnN + 1];
            for (Text value : values) {
                String str = value.toString();
                String[] strs = str.split(",");
                if (strs[0].equals("M")) {
                    mArray[Integer.parseInt(strs[1])] = Integer
                            .parseInt(strs[2]);
                } else { // N
                    nArray[Integer.parseInt(strs[1])] = Integer
                            .parseInt(strs[2]);
                }
            }
            for (int i = 1; i <= rowM; i++) {
                for(int j = 1;j <= columnN;j ++){
//                    System.out.println("mArray[i]:  "+mArray[i]+"nArray[j]:   "+nArray[j]);
                    context.write(new Text(i+","+j), new IntWritable(mArray[i]*nArray[j]));
                }
            }
        }
        
    }
    private static class MatrixMapper2 extends Mapper<LongWritable, Text, Text, IntWritable>{

        @Override
        protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException {
            String str = value.toString();
            String keyOut[] = str.split("	");
            context.write(new Text(keyOut[0]), new IntWritable(Integer.parseInt(keyOut[1])));
        }
    }
    
    private static class MatrixReducer2 extends Reducer<Text, IntWritable, Text, Text> {
        
        @Override
        protected void reduce(Text key, Iterable<IntWritable> values, Reducer<Text, IntWritable, Text, Text>.Context context)
                throws IOException, InterruptedException {
            int sum = 0;
            for(IntWritable value : values){
                sum += value.get();
            }
            context.write(key, new Text(""+sum));
        }
        
    }
    
    public static void runFirstReduce() throws Exception{
        Configuration config = HadoopCfg.getInstance();
        config.setInt("rowM",2);
        config.setInt("columnM",2);
        config.setInt("columnN",3);
        
        Job job = Job.getInstance(config,"矩阵运算第一次reduce");
        job.setJarByClass(Matrix.class);
        job.setMapperClass(MatrixMapper.class);
        job.setMapOutputKeyClass(IntWritable.class);
        job.setMapOutputValueClass(Text.class);
        
        job.setReducerClass(MatrixReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        
        FileInputFormat.addInputPath(job, new Path("/MatrixInput"));
        FileOutputFormat.setOutputPath(job,new Path("/output/reduce1"));
        job.waitForCompletion(true);
        
    }
    
    public static void runSecondReduce() throws Exception{
        Configuration config = HadoopCfg.getInstance();
        
        Job job = Job.getInstance(config,"矩阵运算第二次reduce");
        job.setJarByClass(Matrix.class);
        job.setMapperClass(MatrixMapper2.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);
        
        job.setReducerClass(MatrixReducer2.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);
        
        FileInputFormat.addInputPath(job, new Path("/output/reduce1"));
        FileOutputFormat.setOutputPath(job,new Path("/output/reduce2"));
        job.waitForCompletion(true);
        
    }
        
    public static void main(String[] args) throws Exception {
        runFirstReduce();
        runSecondReduce();
        
    }
}

普通方法：

package org.bigdata508.util;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
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.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.bigdata.util.HadoopCfg;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;

/*
 * 2016-5-8
 * @author:lixin
 * 求矩阵乘积
 * */
public class Matrix {
    
    public static int tFlag = 0;
    private static class MatrixMapper extends Mapper<LongWritable, Text, Text, Text>{

        private static int columnN = 0;
        private static int rowM = 0;
        
        @Override
        protected void setup(Mapper<LongWritable, Text, Text, Text>.Context context)
                throws IOException, InterruptedException {
//            Configuration conf = HadoopCfg.getInstance();
            columnN = 3;//conf.getInt("columnN",0);
            rowM = 2;//conf.getInt("rowM",0);
        }
        
        
        @Override
        protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, Text, Text>.Context context)
                throws IOException, InterruptedException {
            FileSplit fileSplit = (FileSplit) context.getInputSplit();
            String fileName = fileSplit.getPath().getName();
            String str = value.toString();
            String[] strs = str.split(",");
            int i = Integer.parseInt(strs[0]);
            String[] strs2 = strs[1].split("	");
            int j = Integer.parseInt(strs2[0]);
            int val = Integer.parseInt(strs2[1]);
            if (fileName.startsWith("M")) {
                for (int count = 1; count <= columnN; count++) {
                    context.write(new Text(i + "," + count), new Text("M," + j
                            + "," + val + ""));
                }
            } else {// fileName == N
                for (int count = 1; count <= rowM; count++) {
                    context.write(new Text(count + "," + j), new Text("N," + i
                            + "," + val + ""));
                }
            }
        }
    }
    
    private static class MatrixReducer extends
            Reducer<Text, Text, Text, IntWritable> {
        private static int columnM = 0;
        
        @Override
        protected void setup(
                Reducer<Text, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException {
//            Configuration config = context.getConfiguration();
            columnM = 2;//config.getInt("columnM", 0);
        }
        
        @Override
        protected void reduce(Text key, Iterable<Text> values,
                Reducer<Text, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException {
            System.out.println(key);
            int finalVal = 0;
            int[] mArray = new int[columnM + 1];
            int[] nArray = new int[columnM + 1];
            for (Text value : values) {
                String str = value.toString();
                String[] strs = str.split(",");
                if (strs[0].equals("M")) {
                    mArray[Integer.parseInt(strs[1])] = Integer
                            .parseInt(strs[2]);
                } else { // N
                    nArray[Integer.parseInt(strs[1])] = Integer
                            .parseInt(strs[2]);
                }
            }
            for (int i = 1; i < columnM + 1; i++) {
                finalVal += (mArray[i] * nArray[i]);
            }
            context.write(key, new IntWritable(finalVal));
        }
        
        }
        
        public static void main(String[] args) throws Exception {
        Configuration config = HadoopCfg.getInstance();
//        config.setInt("rowM",100);
//        config.setInt("columnM",90);
//        config.setInt("columnN",70);
        
        Job job = Job.getInstance(config,"矩阵运算");
        job.setJarByClass(Matrix.class);
        job.setMapperClass(MatrixMapper.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(Text.class);
        
        job.setReducerClass(MatrixReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        
        FileInputFormat.addInputPath(job, new Path("/MatrixInput"));
        FileOutputFormat.setOutputPath(job,new Path("/output/"));
        System.exit(job.waitForCompletion(true)? 0 : 1);
        
        }
}

M-Matrix
1,1    1
1,2    2
2,1    1
2,2    3

N-Matrix
1,1    1
1,2    2
1,3    4
2,1    1
2,2    3
2,3    8