如何深拷贝 List<Object> [重复]

Question

我有一个对象，这个对象还包括其他对象，比如这个

学生：

    public class Student implements Cloneable {
    public int id;
    public String name;
    public List<Integer> score;
    public Address address;

    ......

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

}

地址：

public class Address implements Serializable,Cloneable{
    public String type;
    public String value;

    ......

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

}

现在我有一个List\<Student> studentsList我如何深拷贝studentsList？如果Address中有其他对象，我如何复制studentList？

Answer 1

您需要实现一个正确的clone() 方法，例如

public class Student implements Cloneable {
    public int id;
    public String name;
    public List<Integer> score;
    public Address address;

    ......

    @Override
    protected Object clone() throws CloneNotSupportedException {
        Student std = new Student();
        std.id = this.id; // Immutable
        std.name = this.name; // Immutable
        std.score = this.score.stream().collect(Collectors.toList()); // Integer is immutable
        std.address = (Adress) this.address.clone();
        return std;
    }