java 集合 Set 插入重复元素

class S{
public int hashCode(){
return 1;
}
public boolean equals(S s){
return true;
}
}

public class Test {

@SuppressWarnings("unchecked")
public static void main(String[] args) throws IOException {
//ClassB b = new ClassB();
//b.show();

Set set = new HashSet();

S s1 = new S();
S s2 = new S();
S s3 = new S();
S s4 = new S();

System.out.println(s1.equals(s2));

set.add(s1);
set.add(s2);
set.add(s3);
set.add(s4);


//set.add(new S());
//set.add(new S());
//set.add(new S());
//set.add(new S());

System.out.println(set.size());// 4

set不能重复说得是不能==，不是不能equals 先这样理解吧

//S s1 = new S();
//S s2 = new S();
//
//System.out.println(s1.equals(s2));

}

}