深层复制与浅层复制（通过clone的方式）_JAVA_编程开发_程序员俱乐部

深层复制与浅层复制
深层复制：Java对象的深层复制是指Java对象A本身被复制成新对象B，同时A的属性也是被复制成新对象，赋值到A的各个属性上去，A与B的相同属性都引用到不同的对象。
浅层复制：A与B的属性没有复制成新的属性。比如： 虽然B与A的地址不同，但是B对象的成员对象与A对象对应的成员对象是同一个对象。


事例如下：
//手机实体类
package com.softstome.clone;

import java.io.Serializable;

public class Phone implements Cloneable,Serializable{
private   String color;
private String  pinpai ; //品牌

private String[] gyss;  

public Phone(){

}

public Phone(String color, String pinpai) {
super();
this.color = color;
this.pinpai = pinpai;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public String getPinpai() {
return pinpai;
}
public void setPinpai(String pinpai) {
this.pinpai = pinpai;
}




public String[] getGyss() {
return gyss;
}

public void setGyss(String[] gyss) {
this.gyss = gyss;
}

@Override
protected Phone clone() throws CloneNotSupportedException {
// TODO Auto-generated method stub
return (Phone)super.clone();
}

}

//学生实体类
package com.softstome.clone;

import java.io.Serializable;

/*
* 实现Serializable接口是为了通过序列化的方式实现深层复制
*
* 实现Cloneable接口是为了通过 clone的方式实现实现深层复制
* */
public class Student implements Cloneable,Serializable {
  private int stid;
  private String stname;
  private Phone phone;

public Student(){

}

public Student(int stid, String stname,Phone phone) {
super();
this.stid = stid;
this.stname = stname;
this.phone=phone;
}

public int getStid() {
return stid;
}
public void setStid(int stid) {
this.stid = stid;
}
public String getStname() {
return stname;
}
public void setStname(String stname) {
this.stname = stname;
}

public Phone getPhone() {
return phone;
}

public void setPhone(Phone phone) {
this.phone = phone;
}

//重写克隆方法  实现对象的拷贝
@Override
protected Student clone() throws CloneNotSupportedException {
// TODO Auto-generated method stub

Student stu=(Student)super.clone();
//要实现深层赋复制 ，必须要有这一句。(去掉则变成浅层拷贝)
stu.phone=phone.clone();
return stu;
}


}

//演示类
package com.softstome.clone;

public class TestClone {



/*
* 拷贝手机对象      
* */

public void testClone1() throws CloneNotSupportedException {
Phone pn=new Phone();
String[] sz={"aa","bb"};
pn.setGyss(sz);


Phone pn1=(Phone)pn.clone();
System.out.println(pn +"   "+pn1);
System.out.println(pn.getGyss()+"   "+pn1.getGyss());

String[] sz1={"cc","dd"};
pn1.setGyss(sz1);
System.out.println(pn.getGyss()+"   "+pn1.getGyss());



}


    /*
     * 拷贝（克隆）学生对象   
     * */

public void testClone2() throws CloneNotSupportedException{

Student stu=new Student(1,"张三",new Phone("红色", "三星"));
Student stu1=(Student)stu.clone();

stu.setStname("张三1");
stu.getPhone().setColor("黑色");
System.out.println(stu.getStid()+"  "+stu.getStname()+"  " +stu.getPhone().getColor());
System.out.println(stu1.getStid()+" "+stu1.getStname()+"  "+stu1.getPhone().getColor());
System.out.println(stu+"  "+stu.getPhone()); //地址完全不同了，确实实现了克隆（浅层克隆）
System.out.println(stu1+"  "+stu1.getPhone());


}


public static void main(String[] args) throws CloneNotSupportedException  {
TestClone test= new  TestClone();
test.testClone1();
//test.testClone2();
}


}