自定义方法实现clone方法（深拷贝）

首先说一下深拷贝与浅拷贝的区别

• 浅拷贝可以拷贝基本数据类型（int、String、char、Boolean等），引用类型不能拷贝（只是拷贝了地址），因为引用类型的数据栈中存放地址，堆中存放相应的属性。
• 深拷贝可以同时拷贝基本数据类型和引用数据类型

可参考浅拷贝实现（注意重写clone方法和实现Cloneable接口）：https://blog.csdn.net/weixin_43960044/article/details/116444705

以Student类举例实现深拷贝，引用数据类型为Car(在student类中实现Car的拷贝)

Student类（实现Cloneable类重写clone方法）：

public class Student implements Cloneable{
    private String name;
    private int age;
    private Car car;

    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 Car getCar() {
        return car;
    }

    public void setCar(Car car) {
        this.car = car;
    }

    public Student(String name, int age, Car car) {
        this.name = name;
        this.age = age;
        this.car = car;
    }

    public Student() {
    }

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

    @Override
    public Student clone() throws CloneNotSupportedException {
    	// 实现拷贝--再拷贝一个Car赋值给Sudent
        Student cloneStudent = (Student) super.clone();
        Car cloneCar = (Car) this.car.clone();
        cloneStudent.setCar(cloneCar);
        return cloneStudent;
    }
}

Car类（实现Cloneable类重写clone方法）：

import java.util.concurrent.Callable;

public class Car implements Cloneable {
    private String brand;



    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public Car() {
    }

    public Car(String brand) {
        this.brand = brand;
    }
    @Override
    public String toString() {
        return "Car{" +
                "brand='" + brand + '\'' +
                '}';
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

测试类：

public class deepCloneTest {
    public static void main(String[] args) throws CloneNotSupportedException {
        Student student = new Student("柳岩", 18, new Car("奥迪"));
        System.out.println(student);
        // 深拷贝测试
        Student student1 = student.clone();
        // 修改克隆的引用对象的属性
        student1.getCar().setBrand("宝马");

        System.out.println(student); // Student{name='柳岩', age=18, car=Car{brand='奥迪'}}
        System.out.println(student1); // Student{name='柳岩', age=18, car=Car{brand='宝马'}}

    }
}