java对象克隆

(要克隆的对象必须要实现 CloneEable 接口 这个接口是一个标志接口(空接口 没有任何的方法实现和属性) 留给jvm处理 )

@Data
@AllArgsConstructor
@NoArgsConstructor
class   Person implements Cloneable{
    String  name;
    Integer age;
    Cat   cat;


    public Person cloneInstance() {
        Person person1 = null;
        try {
            person1 = (Person)super.clone();
            // 嵌套赋值  如果当前对象的属性中  没有cat  那么是不需要这行代码的
            person1.setCat(this.cat.cloneInstance());
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return  person1;

    }
}


@Data
@AllArgsConstructor
@NoArgsConstructor
class   Cat implements Cloneable{
    String   catname;



    public Cat cloneInstance() {
        Cat cat = null;
        try {
            cat = (Cat)super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return  cat;

    }
}

测试案例


    public static void main(String[] args) {
        Cat jerry = new Cat("jerry");
        Person person = new Person("tom",10,jerry);
        
        System.out.println(person);
        System.out.println(System.identityHashCode(person));

        Person person1 = person.cloneInstance();
        System.out.println(person1);
        System.out.println(System.identityHashCode(person1));
    }

输出结果
Person(name=tom, age=10, cat=Cat(catname=jerry))
1554874502
Person(name=tom, age=10, cat=Cat(catname=jerry))
1846274136