1. 所有对象都实现克隆方法
2. 通过构造方法实现深克隆
3. 使用JDK自带的字节流实现深克隆
(1)所有对象都实现克隆方法,这种方式需要让所有的引用对象都实现克隆（Cloneable 接口）
点击查看代码
package com.clone;
public class CloneExample {
public static void main(String[] args) throws CloneNotSupportedException {
//创建被赋值对象
Address address=new Address(001,"北京");
People p1=new People(1,"Java",address);
//克隆p1对象
People p2 = p1.clone();
//修改原型对象
p2.getAddress().setCity("深圳");
//输出p1和p2地址信息
System.out.println("p1:" +p1.getAddress().getCity()+"p2:"+p2.getAddress().getCity());
}
static class People implements Cloneable{
private Integer id;
private String name;
private Address address;
@Override
protected People clone() throws CloneNotSupportedException {
People people = (People) super.clone();
people.setAddress(this.address.clone());
//引用类型克隆赋值
return people;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public People(Integer id, String name, Address address) {
this.id = id;
this.name = name;
this.address = address;
}
}
static class Address implements Cloneable{
private Integer id;
private String city;
public Address(Integer id, String city) {
this.id = id;
this.city = city;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
@Override
protected Address clone() throws CloneNotSupportedException {
return(Address)super.clone();
}
}
}
(2)通过构造方法实现深克隆
点击查看代码
package com.clone;
public class SecondExample {
public static void main(String[] args) {
//创建对象
Address address=new Address(001,"北京");
People p1=new People(1,"Java",address);
//调用构造函数克隆对象
//如果构造器的参数为基本数据类型或字符串类型则直接赋值，如果是对象类型，则需要重新 new 一个对象
People p2 = new People(p1.getId(), p1.getName(), new Address(p1.getAddress().getId(), p1.getAddress().getCity()));
//修改原型对象
p1.getAddress().setCity("广州");
//输出p1和p2地址信息
System.out.println("p1:"+p1.getAddress().getCity()+"p2:"+p2.getAddress().getCity());
}
static class People {
private Integer id;
private String name;
private Address address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public People(Integer id, String name, Address address) {
this.id = id;
this.name = name;
this.address = address;
}
}
static class Address {
private Integer id;
private String city;
public Address(Integer id, String city) {
this.id = id;
this.city = city;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}
}
(3)使用JDK自带的字节流实现深克隆
点击查看代码
package com.clone;
import java.io.*;
public class ThirdExample {
public static void main(String[] args) {
//创建对象
Address address = new Address(001, "北京");
People p1 = new People(1, "java", address);
//通过字节流实现克隆
People p2 = (People) StreamClone.clone(p1);
//修改原型对象
p1.getAddress().setCity("上海");
//输出p1和p2地址信息
System.out.println("p1:"+p1.getAddress().getCity()+"p2:"+p2.getAddress().getCity());
}
static class StreamClone{
public static <T extends Serializable> T clone(People obj){
T cloneObj=null;
try {
ByteArrayOutputStream bo = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bo);
oos.writeObject(obj);
oos.close();
//分配内存，写入原始对象，生成新对象
ByteArrayInputStream bi = new ByteArrayInputStream(bo.toByteArray());
//获取上面的输出字节流
ObjectInputStream oi = new ObjectInputStream(bi);
//返回生成新的对象
cloneObj=(T) oi.readObject();
oi.close();
} catch (Exception e) {
e.printStackTrace();
}
return cloneObj;
}
}
static class People implements Serializable {
private Integer id;
private String name;
private Address address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public People(Integer id, String name, Address address) {
this.id = id;
this.name = name;
this.address = address;
}
}
static class Address implements Serializable{
private Integer id;
private String city;
public Address(Integer id, String city) {
this.id = id;
this.city = city;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}
}