obj1.equals(object obj2)
1==Objectequals
2null
obj.getClass()
1obj.getClass()classclass+==
2obj.getClass().getName()==
obj.toString()+@+瀵硅薄//
obj.hashCodeint
@Data @NoArgsConstructor @AllArgsConstructor public class StringEquals { private int num; public boolean equals(Object obj){ //Object obj=new StringEquals();类型提升; if (!(obj instanceof StringEquals)) { return false; } StringEquals stringEquals=(StringEquals)obj;//类型转变，下降； return this.num==stringEquals.num; } } 2、测试：
public class Test { public static void main(String[] args){ StringEquals s1 = new StringEquals(4); StringEquals s2 = new StringEquals(4); System.out.println(s1.equals(s2)); } }