hadoop-1.x的运行实例

我的环境是hadoop-0.20.2,eclipse：SDK-3.3.2,

源数据为：

Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84
Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84
Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84
Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84
Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84
Apr 23 11:49:54 hostapd: wlan0: STA 14:7d:c5:9e:fb:84

想要获取的数据是：

Apr 23 14:7d:c5:9e:fb:84
Apr 23 14:7d:c5:9e:fb:84
Apr 23 14:7d:c5:9e:fb:84
Apr 23 14:7d:c5:9e:fb:84
Apr 23 14:7d:c5:9e:fb:84
Apr 23 14:7d:c5:9e:fb:84

运行时输入的参数是：
hdfs的输入和输出目录：即 hdfs://cMaster:/user/joe/in    hdfs://cMaster:/user/joe/out

源代码：

package hadoop;
 
import java.io.IOException;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.io.*;
import org.apache.hadoop.util.*;
public class test extends Configured implements Tool{
    enum Counter{
        LINESKIP,
    }
    public static class Map extends Mapper<LongWritable,Text,NullWritable,Text>{
        public void map(LongWritable key,Text value,Context context)throws IOException,InterruptedException{
            String line=value.toString();
            try{
                String [] lineSplit=line.split(" ");
                String month=lineSplit[0];
                String time=lineSplit[1];
                String mac=lineSplit[6];
                Text out=new Text(month+' '+time+' '+mac);
                context.write(NullWritable.get(),out);
            }catch(java.lang.ArrayIndexOutOfBoundsException e){
                context.getCounter(Counter.LINESKIP).increment(1);
                return;
            }
        }
    }
    public int run(String[] args)throws Exception{
        Configuration conf=getConf();
        Job job=new Job(conf,"test");
        job.setJarByClass(test.class);
        FileInputFormat.addInputPath(job,new Path(args[0]));
        FileOutputFormat.setOutputPath(job,new Path(args[1]));
        job.setMapperClass(Map.class);
        job.setOutputFormatClass(TextOutputFormat.class);
        job.setOutputKeyClass(NullWritable.class);
        job.waitForCompletion(true);
        return job.isSuccessful()?0:1;
    }
    public static void main(String[] args)throws Exception{
        int res=ToolRunner.run(new Configuration(),new test(),args);
        System.exit(res);
    }
}