jobcontrol

jobcontrol可以实现多个job结合起来运行。下面就是有两个job的jobcontrol，第一个job的输出是第二个job的输入。

package hadoop;

import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.lib.MultipleTextOutputFormat;
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.jobcontrol.ControlledJob;
import org.apache.hadoop.mapreduce.lib.jobcontrol.JobControl;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.MultipleOutputs;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

import scala.reflect.generic.Trees.New;

public class WordCount {

	public static class WordCountMapper extends Mapper{
		private static final IntWritable Number = new IntWritable(1);
		private Text word = new Text();
		@Override
		protected void map(Object key, Text value, Context context)
				throws IOException, InterruptedException {
			StringTokenizer stringTokenizer = new StringTokenizer(value.toString());
			while(stringTokenizer.hasMoreTokens()){
				String string = stringTokenizer.nextToken();
				word.set(string);
				context.write(word, Number);
			}
		}
		
	}
	
	public static class WordCountReduce extends Reducer{

		@Override
		protected void reduce(Text key, Iterable vlaues,
				Context context) throws IOException, InterruptedException {
			int num=0;
			for(IntWritable intWritable:vlaues){
				num+=intWritable.get();
				
			}
			context.write(key, new IntWritable(num));
		}

	}
	public static class WordCountMapper1 extends Mapper{
		private static final IntWritable Number = new IntWritable(1);
		private Text word = new Text();
		@Override
		protected void map(Object key, Text value, Context context)
				throws IOException, InterruptedException {
			StringTokenizer stringTokenizer = new StringTokenizer(value.toString());
			while(stringTokenizer.hasMoreTokens()){
				String string = stringTokenizer.nextToken();
				word.set(string);
				context.write(word, Number);
			}
		}
		
	}
	
	public static class WordCountReduce1 extends Reducer{
		
		@Override
		protected void reduce(Text key, Iterable vlaues,
				Context context) throws IOException, InterruptedException {
			int num=0;
			for(IntWritable intWritable:vlaues){
				num+=intWritable.get();
				
			}
			context.write(key, new IntWritable(num));
		}
		
	}
	
	public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
		Configuration conf = new Configuration();
		String[] argsValues = new GenericOptionsParser(conf, args).getRemainingArgs();
		
		JobControl jobControl = new JobControl("jobcontrol");
		
		Job job = new Job(conf, "word count1");  
		job.setJarByClass(WordCount.class);
		job.setMapperClass(WordCountMapper.class);
		job.setReducerClass(WordCountReduce.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
		FileInputFormat.addInputPaths(job, argsValues[0]);
		FileOutputFormat.setOutputPath(job, new Path(argsValues[1]));
		
		
		Job job2 = new Job(conf, "word count2");  
		job2.setJarByClass(WordCount.class);
		job2.setMapperClass(WordCountMapper1.class);
		job2.setReducerClass(WordCountReduce1.class);
		job2.setOutputKeyClass(Text.class);
		job2.setOutputValueClass(IntWritable.class);
		FileInputFormat.addInputPaths(job2, argsValues[1]);
		FileOutputFormat.setOutputPath(job2, new Path(argsValues[2]));
		
		ControlledJob controlledJob = new ControlledJob(conf);
		controlledJob.setJob(job);
		ControlledJob controlledJob2 = new ControlledJob(conf);
		controlledJob2.setJob(job2);
		controlledJob2.addDependingJob(controlledJob);
		jobControl.addJob(controlledJob);
		jobControl.addJob(controlledJob2);
		Thread thread = new Thread(jobControl);
		thread.start();
		while(true){
			if(jobControl.allFinished()){
				System.out.println(jobControl.getSuccessfulJobList());
				jobControl.stop();
				break;
			}
		}
	}
	
}

输出结果为

[hadoop@master local]$ hadoop fs -cat  /test/test.txt

hello
hadoop
hello hi 

[hadoop@master local]$ hadoop fs -ls /test/output
Found 2 items
-rw-r--r--   1 hadoop supergroup          0 2017-06-20 14:55 /test/output/_SUCCESS
-rw-r--r--   1 hadoop supergroup         22 2017-06-20 14:55 /test/output/part-r-00000
[hadoop@master local]$ hadoop fs -cat /test/output/part-r-00000
hadoop	1
hello	2
hi	1
[hadoop@master local]$ hadoop fs -ls  /test/output1
Found 2 items
-rw-r--r--   1 hadoop supergroup          0 2017-06-20 14:57 /test/output1/_SUCCESS
-rw-r--r--   1 hadoop supergroup         30 2017-06-20 14:57 /test/output1/part-r-00000
[hadoop@master local]$ hadoop fs -cat /test/output1/part-r-00000
1	2
2	1
hadoop	1
hello	1
hi	1