package aj.hadoop.monitor.mapreduce;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import java.lang.*;
import java.lang.management.*;
import java.util.StringTokenizer;

import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.mapreduce.Mapper.Context;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.Signature;

import aj.hadoop.monitor.util.PickerClient;

@Aspect
public abstract class MapperMonitor {

	private String HOST = "localhost";
	private int PORT = 9999;

	@Pointcut ("call(void org.apache.hadoop.mapreduce.Mapper.Context+.write" +
			"(" +
			"java.lang.Object, " +
			"java.lang.Object" +
			"))" +
			"&& args(key, value)")
	public void pointcut_mapper_out(Object key, Object value){}

	@Before ("pointcut_mapper_out( key, value )")
	public void logging( JoinPoint thisJoinPoint,
			Object key,
			Object value) {
		PickerClient client = new PickerClient();
		client.setHost(this.HOST);
		client.setPORT(this.PORT);
		client.send((String)key);
	}
}

package aj.hadoop.monitor.mapreduce;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import java.lang.*;
import java.lang.management.*;
import java.util.StringTokenizer;

import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.mapreduce.Mapper.Context;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.Signature;

import aj.hadoop.monitor.util.PickerClient;
import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.logging.FileHandler;


@Aspect
public abstract class MapperMonitor {

	private String HOST = "localhost";
	private int PORT = 9999;
	
	/** log file */
	public static final String LOGFILE = "Hanoi-MethodTraceMonitor.log";
	
	/** logger */
	private Logger logger = null;
	
	/** file handler */
	private FileHandler fh = null;
	
	/**
	 * initialize
	 */
	public MapperMonitor() {
		logger = Logger.getLogger(this.getClass().getName());
		try {
			fh = new FileHandler(this.LOGFILE, true);
			logger.addHandler(fh);
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		logger.log(Level.INFO, "Start trace...");
	}

	@Pointcut ("call(void org.apache.hadoop.mapreduce.Mapper.Context+.write" +
			"(" +
			"java.lang.Object, " +
			"java.lang.Object" +
			"))" +
			"&& args(key, value)")
	public void pointcut_mapper_out(Object key, Object value){}

	@Before ("pointcut_mapper_out( key, value )")
	public void logging( JoinPoint thisJoinPoint,
			Object key,
			Object value) {
		PickerClient client = new PickerClient();
		client.setHost(this.HOST);
		client.setPORT(this.PORT);
		client.send((String)key);
		System.err.println("** [POINTCUT]" + (String)key);
	}
}

add logger.