对于一个普通的对象来说,如果实现Cloneable接口,并重写clone方法可以实现对象的深拷贝。
但是对于List/Set等集合来说不管是用集合的clone方法还是对象的clone方法都是浅拷贝,即指针的引用,如果要实现java集合的深拷贝必须将对象实现Serializable接口后写一个深拷贝方法才行。
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class test {
public static void main(String[] args) {
List<Human> sdf = new ArrayList<Human>();
sdf.add(new Human("sdf1", 100));
sdf.add(new Human("sdf2", 200));
List<Human> h3c = null;
try {
h3c = deepCopy(sdf);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Human h1 = h3c.get(0);
h1.name = "h3c";
System.out.println(sdf.get(0).name + "-" + sdf.get(0).age);
System.out.println(h3c.get(0).name + "-" + h3c.get(0).age);
}
static class Human implements Serializable {
String name;
int age;
public Human(String n, int a) {
this.name = n;
this.age = a;
}
}
//关键代码 执行序列化和反序列化 进行深度拷贝
public static <T> List<T> deepCopy(List<T> src) throws IOException, ClassNotFoundException {
ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(byteOut);
out.writeObject(src);
ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());
ObjectInputStream in = new ObjectInputStream(byteIn);
@SuppressWarnings("unchecked")
List<T> dest = (List<T>) in.readObject();
return dest;
}
}
原文:http://blog.csdn.net/h3c4lenovo/article/details/40898477