HashSet如何检查两个对象？

Question

class TestA extends Foo{
   private String a;
   private String b;
   private String c;

   public int hashcode() {
     // Use some inbuilt hashcode generator over a, b, c.
   }

   public boolean equals(Object a) {
     // a, b, c instance variables should match
   }
}

class TestB Extends Foo{
   private String a;
   private String b;
   private String c;

   public int hashcode() {
     // Same as Test A class implementation
   }

   public boolean equals(Object a) {
     // Same as Test A class implementation
   }
}

说我将以下对象添加到HashSet中：

TestA a = new TestA("a", "b", "c")

set.add(a);

现在，如果我检查哈希集中的以下对象b，set.contains(b)总是返回true吗？

TestB B = new TestB("a", "b", "c")

Answer 1

由于您的HashSet应该为HashSet<TestA>，所以您甚至无法编译将TestB实例作为参数编译到contains中。