查看两个集合中有没有相同的元素的方法。Collections disjoint

 1 import java.util.Collections;
 2 import java.util.HashSet;
 3 import java.util.Set;
 4 
 5 public class Demo {
 6 
 7     public static void main(String[] args) {
 8         Set<String> set1 = new HashSet<String>();
 9         Set<String> set2 = new HashSet<String>();
10         
11         set1.add("1");
12         set1.add("1111");
13         set1.add("2222");
14         set2.add("222");
15         set2.add("333");
16         set2.add("111");
17         boolean aaa = Collections.disjoint(set1, set2);
18         System.out.println(aaa);
19     }
20 
21 }