Program which print duplicate number from Array in java

Write a program which print duplicate number from Array in java?

package netsurfingzone;

public class ShowsDuplicateNumber {

	public static void main(String[] args) {

		int arr[] = { 4, 2, 4, 5, 2, 3, 1 };

		int size = arr.length;

		int i, j;

		System.out.println("duplicate Elements are :");

		for (i = 0; i < size; i++) {

			for (j = i + 1; j < size; j++) {

				if (arr[i] == arr[j])

					System.out.print(arr[i] + " ");
			}

		}

	}

}