Java Important Programs

package java3;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import java.util.TreeSet;

public class met {

      public static int[] output1;

      public static void fn(ArrayList<Integer> ip1, ArrayList<Integer> ip2, char c) {

            List<Integer> output = new ArrayList<Integer>();

            switch (c) {

            case '+':

                  output.addAll(ip1);

                  output.addAll(ip2);

                  Set<Integer> s = new HashSet<Integer>(output);

                  output = new ArrayList<Integer>(s);

                  break;

            case '*':

                  ip1.retainAll(ip2);

                  output = ip1;

                  break;

            case '-':

                  ip1.removeAll(ip2);

                  output = ip1;

                  break;

            }

            output1 = new int[output.size()];

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

                  output1[i] = output.get(i);

      }

      public static void main(String[] args) {

            ArrayList<Integer> ip1 = new ArrayList<Integer>();

            ArrayList<Integer> ip2 = new ArrayList<Integer>();

            ip1.add(1);

            ip1.add(12);

            ip1.add(3);

            ip2.add(3);

            ip2.add(5);

            ip2.add(7);

            fn(ip1, ip2, '+');

            for (int i = 0; i < output1.length; i++)

                  System.out.println(output1[i]);

      }

}