java 深拷贝

普通拷贝只拷贝该对象的字段值，该对象里引用的其他对象不进行拷贝，保留原来的引用。所以需要深拷贝。

public class Car implements Cloneable {

    private String name;

    public Car(String name) {
        this.name = name;
    }

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

public class Person implements Cloneable {
    private String name;
    private Car car;

    public Person(String name, Car car) {
        this.name = name;
        this.car = car;
    }

    public Object clone() throws CloneNotSupportedException {
        Person p = (Person)super.clone();
        p.car = (Car)car.clone();
        return p;

    }

    public static void main(String[] args) throws Exception {
        Car car = new Car("aodi");
        Person p1 = new Person("lihao", car);
        System.out.println("car hashcode:" + car.hashCode());
        Person p2 = (Person)p1.clone();
        System.out.println("p1 hashcode:" + p1.hashCode());

        System.out.println("p2's car  hashcode:" + p2.car.hashCode());
        System.out.println("p2 hashcode:" + p2.hashCode());

    }
}