MapReduce 多文件输入

---

title: MapReduce 多文件输入
date: 2016-06-16 16:26:16
tags: MapReduce

---

多路径输入

1. FileInputFormat.addInputPath 多次调用加载不同路径
   FileInputFormat.addInputPath(job, new Path(args[0])); FileInputFormat.addInputPath(job, new Path(args[1]));
2. FileInputFormat.addInputPaths一次调用加载 多路径字符串用逗号隔开
   FileInputFormat.addInputPaths(job, "hdfs://master:9000/cs/path1,hdfs://RS5-112:9000/cs/path2");
3. 多种输入**MultipleInputs可以加载不同路径的输入文件，并且每个路径可用不同的
   maperMultipleInputs.addInputPath(job, new Path("hdfs://RS5-112:9000/cs/path1"), TextInputFormat.class,MultiTypeFileInput1Mapper.class); MultipleInputs.addInputPath(job, new Path("hdfs://RS5-112:9000/cs/path3"), TextInputFormat.class,MultiTypeFileInput3Mapper.class);

例子：

package example;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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.input.MultipleInputs;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
/**
* 多类型文件输入
* @author lijl
*
*/

public class MultiTypeFileInputMR {
static class MultiTypeFileInput1Mapper extends Mapper{
public void map(LongWritable key,Text value,Context context){
try {
String[] str = value.toString().split("\\|");
context.write(new Text(str[0]), new Text(str[1]));
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
static class MultiTypeFileInput3Mapper extends Mapper{
public void map(LongWritable key,Text value,Context context){
try {
String[] str = value.toString().split("");
context.write(new Text(str[0]), new Text(str[1]));
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
static class MultiTypeFileInputReducer extends Reducer{
public void reduce(Text key,Iterable values,Context context){
try {
for(Text value:values){
context.write(key,value);
}

} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

public static void main(String[] args) throws IOException, InterruptedException, ClassNotFoundException {
Configuration conf = new Configuration();
conf.set("mapred.textoutputformat.separator", ",");
Job job = new Job(conf,"MultiPathFileInput");
job.setJarByClass(MultiTypeFileInputMR.class);
FileOutputFormat.setOutputPath(job, new Path("hdfs://RS5-112:9000/cs/path6"));

job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);

job.setReducerClass(MultiTypeFileInputReducer.class);
job.setNumReduceTasks(1);
MultipleInputs.addInputPath(job, new Path("hdfs://RS5-112:9000/cs/path1"), TextInputFormat.class,MultiTypeFileInput1Mapper.class);
MultipleInputs.addInputPath(job, new Path("hdfs://RS5-112:9000/cs/path3"), TextInputFormat.class,MultiTypeFileInput3Mapper.class);
System.exit(job.waitForCompletion(true)?0:1);
}

}

自己例子

QLMapper.java

package com.hdu.mr;

import java.io.IOException;

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

public class QLMapper extends Mapper {
    String[] mbUnlike = { "盒子", "助手", "输入法", "平台" };
    String mbdylxLike = "游戏";
    String mbdylxUnlike = "网页游戏";
    String delWeb = "访问网站";
    Text outputValue = new Text();

    @Override
    protected void map(LongWritable key, Text value, Mapper.Context context)
            throws IOException, InterruptedException {
        // 接收数据v1
        String line = value.toString();
        // 切分数据
        String[] words = line.split("�");
        // String[] words = line.split("\t");

        boolean flag = true;

        for (int i = 0; i < 4; i++) {
            if (words.length < 5) { // 过滤 长度小于4的信息 即访问网站等
                flag = false;
                break;
            }
            if (words[3].indexOf(mbUnlike[i]) != -1) { // 有其中一个则为false
                flag = false;
                break;
            }
        }

        if (flag == true) {
            if (words[4].indexOf(mbdylxUnlike) != -1) { // 有网页游戏则为false
                flag = false;
            } else if (words[4].indexOf(mbdylxLike) == -1) { // 没有游戏则为false
                flag = false;
            }
        }
        if (flag == true) {
            outputValue.set(line);
            context.write(outputValue, new LongWritable(1L));
        }
    }

}

QLReducer.java

package com.hdu.mr;

import java.io.IOException;

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

public class QLReducer extends Reducer {

    @Override
    protected void reduce(Text key, Iterable values,
            Reducer.Context context) throws IOException, InterruptedException {
        // 接收数据

        // 输出
        context.write(key, NullWritable.get());
    }
}

DataClean.java

package com.hdu.mr;

import java.io.IOException;

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

public class QLReducer extends Reducer {

    @Override
    protected void reduce(Text key, Iterable values,
            Reducer.Context context) throws IOException, InterruptedException {
        // 接收数据

        // 输出
        context.write(key, NullWritable.get());
    }
}