java unmodifiedlist_java unmodifiedList用法總結 | 學步園

1、可以通過修改底層的list，到時view被修改

2、不可以進行add、remove操作

3、但是對於mutable的對象，可以改變對象的域值

以下為一個簡單的例子：

import java.util.*;

public class Threadlocal {

static class Person {

private String firstName;

private String secondName;

public Person(String firstName, String secondName) {

this.firstName = firstName;

this.secondName = secondName;

}

public void setFirstName(String firstName) {

this.firstName = firstName;

}

@Override

public String toString() {

return firstName + secondName;

}

}

public static void main(String[] args) {

List list = new ArrayList();

list.add(new Person("a", "b"));

list.add(new Person("c", "d"));

List immutablelist = Collections.unmodifiableList(list);

Iterator iter = immutablelist.iterator();

while(iter.hasNext()) {

System.out.println(iter.next());

}

//change the first Person's firstName

immutablelist.get(0).setFirstName("m");

iter = immutablelist.iterator();

while(iter.hasNext()) {

System.out.println(iter.next());

}

}

}

運行結果：