Question

I have posted question: how to use log4j in Multithread using java?. i got response i tried with one solution, using this solution i have create different log files for each thread but the contain of each thread will mess up.

WorkThread.java

package com.demo;


import com.arosys.customexception.KeyNotFoundException;
import com.arosys.doqeap.exception.NullObjectFoundException;
import com.arosys.doqeap.exception.ValueNotFoundException;
import com.arosys.doqeap.serviceconfiguration.ServiceConfiguration;
import com.arosys.logger.LoggerFactory;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.QueueingConsumer;
import java.io.IOException;
import org.apache.log4j.FileAppender;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PatternLayout;


class wokerThread implements Runnable 
{ 
    private Connection connection; 
    private String requestExchangeName = null;
    private String requestQueueName = null;
    private String requestRoutingKey = null;
    private boolean durable = true;
    private ServiceConfiguration serviceConfiguration = null;

     public wokerThread(ServiceConfiguration config, Connection conn) 
     {

      this.connection=conn; 
          this.serviceConfiguration=config;
     } 

    public void init() throws  KeyNotFoundException, NullObjectFoundException, com.arosys.doqeap.exception.KeyNotFoundException, ValueNotFoundException
    {

        if(connection == null)   throw new NullObjectFoundException("MQConnection object found NULL(First set this Object)");
        if(serviceConfiguration == null)   throw new NullObjectFoundException("ServiceConfiguration object found NULL(First set this Object)");
        requestExchangeName = serviceConfiguration.getValue("request.exchangename");
        requestQueueName =serviceConfiguration.getValue("request.queuename");
        requestRoutingKey = serviceConfiguration.getValue("request.routekeyname");


    }  // end of init()


    public void run()
    {


        Channel channel=null;
        QueueingConsumer consumer = null;
        QueueingConsumer.Delivery delivery = null;
        boolean noAck = false;
        String exchangeType = "direct";

          Logger logger1=LoggerFactory.getLogger(" com.demo.wokerThread","resources/log4j.xml");
          logger1.removeAllAppenders();
          FileAppender appender = null;
          PatternLayout layout = new PatternLayout();
          layout.setConversionPattern("%d{yyyy-MM-dd HH:mm:ss} %p %c{1}:%L - %m%n");
          try {

               appender = new FileAppender(layout,"logs\\worker"+Thread.currentThread().getName()+".log",true);
               logger1.addAppender(appender);
               logger1.setLevel((Level) Level.DEBUG);    
            } catch (IOException ex) {
              ex.printStackTrace();
            }


        logger1.info("Thread name-"+ Thread.currentThread().getName());
        logger1.info("Appender Name "+appender.getFile());

        Thread runThread = Thread.currentThread();


        try    // try 
        {          
                 channel = connection.createChannel();
                 channel.exchangeDeclare(requestExchangeName, exchangeType, durable);
                 channel.queueDeclare(requestQueueName, durable,false,false,null);
                 channel.basicQos(1);
                 channel.queueBind(requestQueueName, requestExchangeName, requestRoutingKey);
                 consumer = new QueueingConsumer(channel);
                 channel.basicConsume(requestQueueName, noAck, consumer);        
                 logger1.info(runThread.getName()+" :: Starting to listen to Request Queue. . . . . . . . . . . ."+runThread);
                    while(true)
                    {

                         delivery = consumer.nextDelivery();
                         logger1.info(runThread+" ::  Message picked up from Queue--"+delivery);
                         channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);

                    } // end of stop while loop

        }
                // end of try 1
        catch(Exception e){  logger1.error(e); } // catch 1        
    } // run
} 

ThreadDemo .java

package com.demo;

import com.arosys.doqeap.exception.DatabaseException;
import com.arosys.doqeap.exception.FileNotFoundException;
import com.arosys.doqeap.exception.KeyNotFoundException;
import com.arosys.doqeap.exception.MQConnectionNotEstablished;
import com.arosys.doqeap.exception.NullObjectFoundException;
import com.arosys.doqeap.exception.ValidationException;
import com.arosys.doqeap.exception.ValueNotFoundException;
import com.arosys.doqeap.mqmanager.MQConnectionManager;
import com.arosys.doqeap.serviceconfiguration.ServiceConfiguration;
import com.rabbitmq.client.Connection;
import java.io.IOException;
import java.net.URISyntaxException;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;


public class ThreadDemo 
{

    public static void main(String s[])
    {
        try {
            ServiceConfiguration sc=new ServiceConfiguration("e:\\07-10\\Development\\standardizationService\\StandardizeAccountService.xml");
            try {
                sc.loadProperties();
            } catch (IOException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            } catch (SQLException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            } catch (ValidationException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            } catch (DatabaseException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            } catch (URISyntaxException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            } catch (FileNotFoundException ex) {
                Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
            }
            MQConnectionManager mq=new MQConnectionManager(sc);
            Connection mQConnection = mq.getMQConnection();
            wokerThread wr=new wokerThread(sc,mQConnection);
            wr.init();
            Thread[] worker=new Thread[2];
            for(int i=0;i<worker.length;i++)
            {
                worker[i]=new Thread(wr,""+i);
                worker[i].start();
            }


        } catch (com.arosys.customexception.KeyNotFoundException ex) {
            Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NullObjectFoundException ex) {
            Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
        } catch (MQConnectionNotEstablished ex) {
            Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ValueNotFoundException ex) {
            Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
        } catch (KeyNotFoundException ex) {
            Logger.getLogger(ThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

Here ThreadDemo class create two thread,and workerTheread class will listen message from queue(RabbitMQ).each thread will read message from queue and write log message on specified log files.

worker0.log

2011-11-24 13:24:35 INFO wokerThread:73 - Thread name-0
2011-11-24 13:24:35 INFO wokerThread:74 - Appender Name logs\worker0.log

worker1.log

2011-11-24 13:24:35 INFO wokerThread:73 - Thread name-1
2011-11-24 13:24:35 INFO wokerThread:74 - Appender Name logs\worker1.log
2011-11-24 13:24:35 INFO wokerThread:88 - 0 :: Starting to listen to Request Queue. . . . . . . . . . . .Thread[0,5,main]
2011-11-24 13:24:35 INFO wokerThread:88 - 1 :: Starting to listen to Request Queue. . . . . . . . . . . .Thread[1,5,main]
2011-11-24 13:24:39 INFO wokerThread:93 - Thread[0,5,main] ::  Message picked up from Queue--com.rabbitmq.client.QueueingConsumer$Delivery@cfec48
2011-11-24 13:24:39 INFO wokerThread:93 - Thread[1,5,main] ::  Message picked up from Queue--com.rabbitmq.client.QueueingConsumer$Delivery@a17083
2011-11-24 13:24:39 INFO wokerThread:93 - Thread[0,5,main] ::  Message picked up from Queue--com.rabbitmq.client.QueueingConsumer$Delivery@e1d5ea
2011-11-24 13:24:39 INFO wokerThread:93 - Thread[0,5,main] ::  Message picked up from Queue--com.rabbitmq.client.QueueingConsumer$Delivery@a31e1b
2011-11-24 13:24:40 INFO wokerThread:93 - Thread[1,5,main] ::  Message picked up from Queue--com.rabbitmq.client.QueueingConsumer$Delivery@10da5eb

according to me,thread0 logging goes on worker0 as well same for thread1 . I am not able to identified where the problem.please help me?

Regards

Answer 1

You’re using the same wokerThread instance for intializing both of your Threads. That way the appenders of the first worker are removed by the second thread and appenders for the second log file (worker1) are added.

Try:

        // wokerThread wr=new wokerThread(sc,mQConnection); --> move this into the loop
        // wr.init(); --> move this into the loop
        Thread[] worker=new Thread[2];
        for(int i=0;i<worker.length;i++)
        {
            wokerThread wr=new wokerThread(sc,mQConnection); // --> moved into the loop
            wr.init(); // --> moved into the loop
            worker[i]=new Thread(wr,""+i);
            worker[i].start();
        }

Wait, that’s not enough. You should configure in each wokerThread instance a different Logger instance. Logger instances are identified by their name, so in wokerThread.java in the run() method, you retrieve different Logger instance by using different names. Here, you can use the current thread’s name to differ between loggers:

  public void run()
  {
      ...
      String threadName = Thread.currentThread().getName(); // --> added line
      // --> now append thread's name to logger name:
      Logger logger1=LoggerFactory.getLogger(" com.demo.wokerThread_" + threadName,"resources/log4j.xml");
      logger1.removeAllAppenders();
      ...
   }