clone java的深克隆和浅克隆

浅复制（浅克隆）：将一个对象复制后，基本数据类型的变量都会重新创建，而引用类型，指向的还是原对象所指向的。

深复制（深克隆）：将一个对象复制后，不论是基本数据类型还有引用类型，都是重新创建的。简单来说，就是深复制进行了完

如有以下两个类

import java.io.Serializable;

public class Teacher implements Cloneable,Serializable {
	private static final long serialVersionUID = 1L;
	private String name;
	private Integer age;
	private String sex;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	
	
}

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class Student implements Cloneable,Serializable {
	private static final long serialVersionUID = 1L;
	private String name;
	private int age;
	private String sex;
	private Teacher teacher;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public Teacher getTeacher() {
		return teacher;
	}
	public void setTeacher(Teacher teacher) {
		this.teacher = teacher;
	}
	// clone
	public Student clone(){
		Student student = null;
		try {
			student = (Student) super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return student;
	}
	
	//deepClone();
	public Student deepClone() throws Exception{
		//将对象写入流
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		ObjectOutputStream oos = new ObjectOutputStream(baos);
		oos.writeObject(this);
		
		//将对象从流中读出
		ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
		ObjectInputStream ois = new ObjectInputStream(bais);
		Student student = (Student) ois.readObject();
		ois.close();
		bais.close();
		oos.close();
		baos.close();
		return  student;
		
	}
	
}

  

 

新建测试类

public class TestCloneApp {
	public static void main(String[] args) throws Exception {
		
		Teacher teacher = new Teacher();
		teacher.setName("张老师");
		teacher.setAge(53);
		teacher.setSex("男");
		
		
		Student student = new Student();
		student.setAge(5);
		student.setName("张三");
		student.setSex("女");
		student.setTeacher(teacher);
		
		//clone
		Student cloneStudent = student.clone();
		
		cloneStudent.setName("李四");
		cloneStudent.setSex("男");
		cloneStudent.getTeacher().setName("李老师");;
		//deepClone
		
		Student deepClone = student.deepClone();
		deepClone.setName("aaa");
		deepClone.setSex("bbb");
		deepClone.getTeacher().setName("cccc");
		System.out.println("person"+"------->"+"name: "+student.getName()+",age: "+student.getAge()+",sex: "+student.getSex()+",teacher: "+student.getTeacher().getName());
		System.out.println("clonePerson"+"------->"+"name: "+cloneStudent.getName()+",age: "+cloneStudent.getAge()+",sex: "+cloneStudent.getSex()+",teacher: "+cloneStudent.getTeacher().getName());
		System.out.println("deepClone"+"  ------->"+"name: "+deepClone.getName()+",age: "+deepClone.getAge()+",sex: "+deepClone.getSex()+",teacher: "+deepClone.getTeacher().getName());
		
	}
}

 

输出结果如下

student------->name: 张三,age: 5,sex: 女,teacher: 李老师

cloneStudent------->name: 李四,age: 5,sex: 男,teacher: 李老师

deepClone  ------->name: aaa,age: 5,sex: bbb,teacher: cccc

 

总结: 

浅克隆会复制一个对象，对象属性是基本类型的会重现创建，相当于复制。而是引用类型的则是指向原对象的引用地址。所以当 cloneStudent 对象改变teacher姓名时，student对象的teacher姓名也改变。

 

深克隆也会复制一个对象，但是不管对象的属性是基本类型还是引用类型，都会重新辅助一份。所以当deepClone 改变任意属性时，原对象（student）的属性都不会受到影响。