Java-clone()

妖狐艹你老母 2021-09-28 22:28 197阅读 0赞

0. 相关：[浅拷贝][Link 1]与[深拷贝][Link 2]

1. java.lang.Object类内的方法

protected Object clone() throws CloneNotSupportedException

2. 作用：创建并返回此对象的副本。

3. 异常：CloneNotSupportedException

如果对象的类不支持Cloneable接口,子类重写clone方法也抛出该异常表示实例无法克隆。

4. 实现对一个实体类的克隆，可以使用Object类的clone()方法，首先要使实体类实现Cloneable接口，并重写clone()方法，返回父类的clone()即可。

实例如下：

package com.basis.entity;
    
    public class Person implements Cloneable {
    
        private String adress;
        private Info info;
    
        public String getAdress() {
            return adress;
        }
    
        public void setAdress(String adress) {
            this.adress = adress;
        }
    
        public Info getInfo() {
            return info;
        }
    
        public void setInfo(Info info) {
            this.info = info;
        }
    
        @Override
        public String toString() {
            return "Person{" +
                    "adress='" + adress + '\'' +
                    ", info=" + info +
                    '}';
        }
    
        public Object clone() throws CloneNotSupportedException{
            return super.clone();
        }
    }

package com.basis.entity;
    
    public class Info {
    
        private String IDCard;
        private String name;
    
        public String getIDCard() {
            return IDCard;
        }
    
        public void setIDCard(String IDCard) {
            this.IDCard = IDCard;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        @Override
        public String toString() {
            return "Info{" +
                    "IDCard='" + IDCard + '\'' +
                    ", name='" + name + '\'' +
                    '}';
        }
    }

package com.company;
    
    import com.basis.entity.Info;
    import com.basis.entity.Person;
    
    public class Main {
    
        public static void main(String[] args) {
    
            Info info = new Info();
            info.setName("张三");
            info.setIDCard("111111");
    
            Person person1 = new Person();
            person1.setAdress("北京");
            person1.setInfo(info);
    
            System.out.println(person1.toString());
    
            Person person2 = null;
            try {
                person2 = (Person)person1.clone();
            } catch (CloneNotSupportedException e) {
                e.printStackTrace();
            }
            System.out.println(person2.toString());
    
        }
    }

结果：

Person{adress='北京', info=Info{IDCard='111111', name='张三'}}
    Person{adress='北京', info=Info{IDCard='111111', name='张三'}}

[Link 1]: https://blog.csdn.net/qq_31150365/article/details/90902246
[Link 2]: https://blog.csdn.net/qq_31150365/article/details/90903740