java中克隆研究

Myth丶恋晨 2022-07-24 05:18 94阅读 0赞

### 实现克隆的步骤 ###

1.  让类实现Cloneable接口
2.  重写clone方法为public,并调用super.clone()

代码示例

public class People implements Cloneable { 
    
        private int age;
    
        private String name;
    
        public People(int age, String name) {
            super();
            this.age = age;
            this.name = name;
        }
    
        public People() {
            super();
        }
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        @Override
        public Object clone() throws CloneNotSupportedException {
            return super.clone();
        }
    
    }

调用

public class Test {
    
        public static void main(String[] args) throws CloneNotSupportedException {
            People people = new People(11, "zzh");
            People copy = (People) people.clone();
            System.out.println(copy.getAge());
        }
    
    }

这是一个浅克隆，如果对象中含有引用其他对象的属性，克隆后引用也将指向同一个对象，深克隆需要自己在clone()方法中实现，例如

public class People implements Cloneable { 
    
        private int age;
    
        private String name;
    
        private Phone phone;
    
        public People(int age, String name) {
            super();
            this.age = age;
            this.name = name;
        }
    
        public People() {
            super();
        }
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    
        public Phone getPhone() {
            return phone;
        }
    
        public void setPhone(Phone phone) {
            this.phone = phone;
        }
    
        @Override
        public People clone() throws CloneNotSupportedException {
            People p = null;
            p = (People) super.clone();
            p.phone = (Phone) phone.clone();
            return p;
        }
    
    }

### 克隆的使用场景 ###

*  比如一个对象的初始化复杂，你需要得到一份相似的对象，使用克隆，将会是一个不错的选择。
 *  克隆在对数组的复制也是十分方便的，可以直接使用。