Information needed regarding Thread Pooling

[Allan Kuruvila]

Hey guys...i have implemented threadpool concept (below) using Exceutor class..can you please let me know whether the steps that i have done is rite???

import java.util.ArrayList;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

 

public class ThreadPoolTest2 {

    public static void main(String[] args) {

       // int numWorkers = 5;                           //Integer.parseInt(args[0]);

        int threadPoolSize =2;                          // setting the number of threads

        String sMessage = null;

        

        ArrayList<String> inputFile = new ArrayList<String>();

                    inputFile.add("D://TestFiles//text1.txt");

                                inputFile.add("D://TestFiles//text2.txt");

                                inputFile.add("D://TestFiles//text3.txt");     // adding the list of files

                                

        ExecutorService tpes = Executors.newFixedThreadPool(threadPoolSize);

 //     ExecutorService tpes = Executors.newCachedThreadPool();

 

        CallableWorkerThread workers[] = new CallableWorkerThread[inputFile.size()];

        Future futures[] = new Future[inputFile.size()];

        if(!tpes.isShutdown()){

           for (int i = 0; i < inputFile.size(); i++) {

                  sMessage = (String)inputFile.get(i);

                  workers[i] = new CallableWorkerThread(sMessage,i);

              futures[i]=tpes.submit(workers[i]);

                }

        }

        

        for (int i = 0; i < inputFile.size(); i++) {

            try {

                System.out.println("Ending reading from file : " +

                    futures[i].get());

            } catch (Exception e) {}

        }

        

//      This will make the executor accept no new threads

                                // and finish all existing threads in the queue

        tpes.shutdown();

                                // Wait until all threads are finish

                                while (!tpes.isTerminated()) {

              System.out.println("Waiting for all the threads to finish up");

                                }

                                System.out.println("Finished all threads");

                }


}

import java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.util.concurrent.Callable;

 

import com.ibm.lh.core.pxml.PXMLEntity;

 

public class CallableWorkerThread implements Callable<String> {

    private String workerMessage1;

    private int workNumber;

 

    CallableWorkerThread(String workerMessage,int workNumber) {

        this.workerMessage1 = workerMessage;

        this.workNumber =workNumber;

    }

 

    public String call() {

                
                try{

                                FileReader fileReader = new FileReader(workerMessage1);

                                BufferedReader bufferedReader = new BufferedReader(fileReader);

                                String inString = null;

                                

                                while((inString =bufferedReader.readLine())!= null){

                                                System.out.println(inString);

                                };

                    bufferedReader.close();

                }catch(FileNotFoundException e){

                                e.printStackTrace();

                } catch (IOException e) {

                                                e.printStackTrace();

                                }catch(Exception e){

                                                e.printStackTrace();

                                }

                                return workerMessage1;

    }

}

Secondly. any tips on how to code this concept using threadpoolexcecutor...have been trying to get some good material, but in vain...so please help me out..

[Devaka Cooray]

Allan, welcome to JavaRanch.
When you UseCodeTags, please use the BB tags [code][/code], instead of the HTML <code></code>
I've corrected it for you now.