List深度复制

昨天弄了一个类似List<Map<String, List<String>>>这样的list的复制，结果无论使用new ArrayList<>(srcList)，还是Collections.copy(dest, src)，貌似都是浅复制，改变新的List就会影响原来的，今天发现下面的方法很简单，记录下来

 

 

 

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.LinkedList;
import java.util.List;

class Cat implements Serializable {
    private String cat;
    public Cat(String name) {
        cat = name;
    }
    public String getCat() {
        return cat;
    }
    public void setCat(String cat) {
        this.cat = cat;
    }
}

public class CopyList {
    public static void main(String[] args) throws IOException,
            ClassNotFoundException {
        LinkedList<Cat> list = new LinkedList<Cat>();
        list.add(new Cat("a"));
        list.add(new Cat("b"));
        // 用原有集合创建新集合
        List<Cat> listCopy = (List<Cat>) deepcopy(list);
        // Collections.copy(listCopy, list);
        listCopy.add(new Cat("c"));
        for (Cat s : listCopy) {
            System.out.println("listCopy:" + s + "--cat:" + s.getCat());
        }
        for (Cat s : list) {
            System.out.println("list:" + s + "--cat:" + s.getCat());
        }
        System.out.println("listCopy:" + listCopy);
        System.out.println("list:" + list);
    }

    public static List deepcopy(List 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);
        List dest = (List) in.readObject();
        return dest;

    }
}