How to find intersection values of two Arrays

public class IntersectionOfArrays {

	//A method to display an array values in standard format
	private static void dispArray(int [] numArray) {

		System.out.println("The Array elements are");
		System.out.print("[ ");
		for (int i = 0; i < numArray.length; i++) {
			System.out.print(numArray[i] + " ");
		}
		System.out.println("]");
	}

	public static void main(String[] args) {

		int [] arrFirst = {5,2,9,12,1,4,73};
		int [] arrSecond = {9,1,2};
		boolean isAvailable = false;
		StringBuilder matchingNums=new StringBuilder("[");
		// Check each number of first array in the second array
		// Nested for loop to handle this logic
		for (int i=0;i<arrFirst.length;i++)
			for (int j=0;j<arrSecond.length;j++)
				if (arrFirst[i]==arrSecond[j]) {
					matchingNums.append(arrFirst[i]+", ");
					isAvailable=true;
				}
		dispArray(arrFirst);
		dispArray(arrSecond);
		if (isAvailable) {
			System.out.println("Intersection numbers from the above two arrays are");
			matchingNums.setCharAt(matchingNums.lastIndexOf(String.valueOf(',')), ']');
			System.out.println(matchingNums);
		}
		else {
			System.out.println("No common numbers in the given two arrays, hence output is empty");
			matchingNums.append("]");
			System.out.println(matchingNums);
		}
	}
}