Parallel for-loop in java

[Prabhjot Jassal]

I am new to concurrency and would be thankful if someone could help.

I wrote the following code which has 2 arrays and in the 3rd array I am storing the answer of corresponding 1st and 2nd array. Can someone please tell me how to make it run in parallel? If possible please tell me 2 methods - 1. Using Threads and 2. Using Java 5 or 6 concurrent library. Thanks

  
import java.io.*;

public class ForLoop {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.print("Please enter the array size: ");
		try {
			int size = Integer.parseInt(new BufferedReader(new InputStreamReader(System.in)).readLine());
			int[] array1 = new int[size];
			int[] array2 = new int[size];

			for (int i = 0; i < size; i++) {
				array1[i] = (int)(Math.random()*100000000);
				array2[i] = (int)(Math.random()*100000000);
			}

			int[] array3 = new int[size];

			long start = System.currentTimeMillis();
			
			for (int i = 0; i < size; i++) {
				array3[i] = array1[i] + array2[i];
			}
			
			long finish = System.currentTimeMillis();

			System.out.println(finish - start);
		} catch (IOException e) {

		}
	}

}

  

[Henry Wong]

The Sun tutorial should be a good place to start learning about threads (and the concurrency package)...

http://download.oracle.com/docs/cd/E17409_01/javase/tutorial/essential/concurrency/

This isn't a subject that you can learn from one example, posted in a forum topic.

Henry