一、Clonable 接口和深拷贝

1.clone接口的使用

注意以下几个点：

import javax.jws.soap.SOAPBinding;

class Person implements Cloneable{
    public String name;
    public int age;

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

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

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}
public class Test {
    public static void main(String[] args) throws CloneNotSupportedException {
        Person person = new Person("张三",10);
        Person person2 = (Person) person.clone();

        System.out.println(person);
        System.out.println(person2);

    }
}

2.浅拷贝和深拷贝

1）浅拷贝

import javax.jws.soap.SOAPBinding;
class Money{
    public double m = 19.9;
}
class Person implements Cloneable{
    public String name;
    public int age;
    public  Money money = new Money();

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

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

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}
public class Test {
    public static void main(String[] args) throws CloneNotSupportedException {
        Person person = new Person("张三",10);
        Person person2 = (Person) person.clone();

        System.out.println(person.money.m);
        System.out.println(person2.money.m);
        System.out.println("===========");
        person.money.m = 99.99;
        System.out.println(person.money.m);
        System.out.println(person2.money.m);

    }
    public static void main1(String[] args) throws CloneNotSupportedException {
        Person person = new Person("张三",10);
        Person person2 = (Person) person.clone();

        System.out.println(person);
        System.out.println(person2);

    }
}

2）深拷贝

import javax.jws.soap.SOAPBinding;
class Money implements Cloneable{
    public double m = 19.9;

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}
class Person implements Cloneable{
    public String name;
    public int age;
    public  Money money = new Money();

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

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

    @Override
    protected Object clone() throws CloneNotSupportedException {
        //深拷贝
        Person tmp = (Person) super.clone(); //将拷贝的第一层的this地址给tmp
        tmp.money = (Money) this.money.clone();//再拷贝第二层this下的money
        return tmp;
        //return super.clone();
    }
}
public class Test {

    public static void main(String[] args) throws CloneNotSupportedException {
        Person person = new Person("张三",10);
        Person person2 = (Person) person.clone();

        System.out.println(person.money.m);
        System.out.println(person2.money.m);
        System.out.println("===========");
        person.money.m = 99.99;
        System.out.println(person.money.m);
        System.out.println(person2.money.m);

    }
    public static void main1(String[] args) throws CloneNotSupportedException {
        Person person = new Person("张三",10);
        Person person2 = (Person) person.clone();

        System.out.println(person);
        System.out.println(person2);

    }
}

二、抽象类和接口的区别

抽象类和接口都是 Java 中多态的常见使用方式.

核心区别 : 抽象类中可以包含普通方法和普通字段 , 这样的普通方法和字段可以被子类直接使用 ( 不必重写 ), 而接口中不能包含普通方法, 子类必须重写所有的抽象方法 .

如之前写的 Animal 例子 . 此处的 Animal 中包含一个 name 这样的属性 , 这个属性在任何子类中都是存在的 . 因此此

处的 Animal 只能作为一个抽象类 , 而不应该成为一个接口

三、object类

Object 是 Java 默认提供的一个类。

Java 里面除了 Object 类，所有的类都是存在继承关系，默认会继承 Object 父类。

即所有类的对象都可以使用Object 的引用进行接收。

绿色的解锁标志：public 公开的

灰色的钥匙：protected 受保护的

橙色的锁：private 私人的