Java之克隆

JAVA克隆对象

一、克隆的含义：克隆一个对象，其属性会保持一样，但两个对象的引用并不相同。

二、克隆的实现：1)clone()方法，返回的是Object对象，需要强制转换；2)类必须实现Cloneable接口，并且重写Objet类的clone（）方法.

三、代码实现

1.定义一个类并实现Cloneable接口

2.重写该类的equals方法

3.测试

package com.zyl.learn.common;

/**
 * Created by zyl on 2015/8/2.
 */
public class Person implements Cloneable {


    private String name;

    private String sex;

    private int age;

    public Person(String name, String sex, int age) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public Object clone() {

        try {
            return super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
            return null;
        }
    }


    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        if (age != person.age) return false;
        if (name != null ? !name.equals(person.name) : person.name != null) return false;
        if (sex != null ? !sex.equals(person.sex) : person.sex != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + (sex != null ? sex.hashCode() : 0);
        result = 31 * result + age;
        return result;
    }
}

3.测试代码

import com.zyl.learn.common.Person;

public class clone {

    public static void main(String[] args) {

        Person person = new Person("xiao ming", "male", 21);

        Person clonePerson = (Person) person.clone();

        System.out.println("人和克隆人属性:" + person.equals(clonePerson));

        System.out.println("人和克隆人:" + (person == clonePerson));


    }
}

4.输出：

人和克隆人属性:true
人和克隆人:false

四、总结

1.克隆类的实现方法

2.克隆对象的本质是独立新空间的复制品