Java交、差、並集

import java.util.HashSet;
import java.util.Set;
 
public class TestSet {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Set<Integer> result = new HashSet<Integer>();
        Set<Integer> set1 = new HashSet<Integer>() {
            {
                add(1);
                add(3);
                add(5);
            }
        };
 
        Set<Integer> set2 = new HashSet<Integer>() {
            {
                add(1);
                add(2);
                add(3);
            }
        };
 
        result.clear();
        result.addAll(set1);
        result.retainAll(set2);
        System.out.println("交集：" + result);
 
        result.clear();
        result.addAll(set1);
        result.removeAll(set2);
        System.out.println("差集：" + result);
 
        result.clear();
        result.addAll(set1);
        result.addAll(set2);
        System.out.println("並集：" + result);
 
    }
 
}