Union of two sorted arrays code in java

import java.util.*;

public class MyFirstClass {

    public static void main(String[] args) {

        int arr1[] = {1,1,2,3,4,5};

int arr2[] = {2,3,4,4,5,10,20,100};

int n1 = arr1.length; int n2=arr2.length;

int leng = n1+n2;

int i=0;int j=0;

ArrayList<Integer> Union = new ArrayList<>();

while(i<n1 && j<n2)

{

if (arr1[i] <= arr2[j]) // Case 1 and 2

{

  if (Union.size() == 0 || Union.get(Union.size()-1) != arr1[i])

Union.add(arr1[i]);

  i++;

} else // case 3

{

  if (Union.size() == 0 || Union.get(Union.size()-1) != arr2[j])

Union.add(arr2[j]);

  j++;

}

  }

while(j<n2)

{

if (Union.size() == 0 || Union.get(Union.size()-1) != arr2[j])

        Union.add(arr2[j]);

      j++;

}

while(i<n1)

{

if (Union.size() == 0 || Union.get(Union.size()-1) != arr1[i])

        Union.add(arr1[i]);

      i++;

}

System.out.println(Union);

    }

}