两种方式:
1). 实现Cloneable接口并重写Object类中的clone()方法;
2). 实现Serializable接口,通过对象的序列化和反序列化实现克隆,可以实现真正的深度克隆,代码如下
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
public class MyUtil {
private MyUtil() {
throw new AssertionError();
}
@SuppressWarnings("unchecked")
public static <T extends Serializable> T clone(T obj) throws Exception {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bout);
oos.writeObject(obj);
ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
ObjectInputStream ois = new ObjectInputStream(bin);
return (T) ois.readObject();
// 说明:调用ByteArrayInputStream或ByteArrayOutputStream对象的close方法没有任何意义
// 这两个基于内存的流只要垃圾回收器清理对象就能够释放资源,这一点不同于对外部资源(如文件流)的释放
}
}
class Student implements Cloneable{
private String name;
private int age;
private StudentClass studentClass;
private List<String> list = new ArrayList<>();
public Student() {
// TODO Auto-generated constructor stub
System.out.println("构造方法被调用");
}
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 StudentClass getStudentClass() {
return studentClass;
}
public void setStudentClass(StudentClass studentClass) {
this.studentClass = studentClass;
}
public void add(String aa){
this.list.add(aa);
}
@Override
public Object clone() throws CloneNotSupportedException {
// TODO Auto-generated method stub
Student stu = (Student) super.clone();
return stu;
}
@Override
public String toString() {
return "Student [name=" + name + ", age=" + age + ",class"+studentClass.getStudentClass()+",list"+list+"]";
}
}