deep clone and shallow clone

deep clone and shallow clone

1. 浅复制(浅克隆):被复制对象的所有变量都含有与原来的对象相同的值，而所有的对其他对象的引用仍然指向原来的对象。换言之，浅复制仅仅复制所考虑的对象，而不复制它所引用的对象。
2. 深复制(深克隆):被复制对象的所有变量都含有与原来的对象相同的值，除去那些引用其他对象的变量。那些引用其他对象的变量将指向被复制过的新对象，而不再是原有的那些被引用的对象。换言之，深复制把要复制的对象所引用的对象都复制一遍。

public class CloneTest1 {
    public static void main(String[] args) throws CloneNotSupportedException {

        Student student = new Student();
        student.setName("bob");
        student.setAge(20);

        Student student1 = (Student) student.clone();
        System.out.println(student1.getName());
        System.out.println(student1.getAge());

        System.out.println("-------------------------");
        student1.setName("lisi");

        System.out.println(student.getName());
        System.out.println(student1.getName());
    }
}

class Student implements Cloneable {

    private int age;

    private String name;

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

public class CloneTest2 {
    public static void main(String[] args) throws CloneNotSupportedException {

        Teacher teacher = new Teacher();
        teacher.setName("teacher li");
        teacher.setAge(28);

        Student2 student = new Student2();
        student.setName("bob");
        student.setAge(18);
        student.setTeacher(teacher);

        Student2 student2 = (Student2) student.clone();
        student2.setTeacher((Teacher) student.getTeacher().clone());

        System.out.println(student2.getName());
        System.out.println(student2.getAge());
        System.out.println(student2.getTeacher().getName());
        System.out.println(student2.getTeacher().getAge());

        student2.getTeacher().setName("teacher zhang");
        System.out.println(student.getTeacher().getName());
        System.out.println(student2.getTeacher().getName());

    }
}

class Teacher implements Cloneable {
    private int age;
    private String name;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

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

class Student2 implements Cloneable {

    private int age;

    private String name;

    private Teacher teacher;

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Teacher getTeacher() {
        return teacher;
    }

    public void setTeacher(Teacher teacher) {
        this.teacher = teacher;
    }
}

public class CloneTest3 {
    public static void main(String[] args) throws CloneNotSupportedException, IOException, ClassNotFoundException {

        Teacher3 teacher = new Teacher3();
        teacher.setName("teacher li");
        teacher.setAge(28);

        Student3 student = new Student3();
        student.setName("bob");
        student.setAge(18);
        student.setTeacher(teacher);

        Student3 student2 = (Student3) student.deepClone();

        System.out.println(student2.getName());
        System.out.println(student2.getAge());
        System.out.println(student2.getTeacher().getName());
        System.out.println(student2.getTeacher().getAge());

        student2.getTeacher().setName("teacher zhang");
        System.out.println(student.getTeacher().getName());
        System.out.println(student2.getTeacher().getName());

    }
}

class Teacher3 implements Serializable {
    private int age;
    private String name;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

class Student3 implements Serializable {

    private int age;

    private String name;

    private Teacher3 teacher;

    public Object deepClone() throws IOException, ClassNotFoundException {

        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        oos.writeObject(this);

        ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
        ObjectInputStream ois = new ObjectInputStream(bis);
        return ois.readObject();
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Teacher3 getTeacher() {
        return teacher;
    }

    public void setTeacher(Teacher3 teacher) {
        this.teacher = teacher;
    }
}