Question

我有<代码>ArrayList,其中载有一些物体,例如<编码>User,每个物体有<代码> 姓名/代码>和<编码><> 密码/编码> 财产。我如何只删除<代码>。用户具体名称来自<条码>的物体 ArrayList

Answer 1

你们可以这样作:

           // If you are using java 8
           userList.removeIf(user-> user.getName().equals("yourUserName"));
           // With older version
           User userToRemove = null;
           for(User usr:userList) {
             if(usr.getName().equals("yourUserName")) {
                userToRemove = usr;
                break;
             }
           }
           userList.remove(userToRemove);

Answer 2

Iterator<User> it = list.iterator();
while (it.hasNext()) {
  User user = it.next();
  if (user.getName().equals("John Doe")) {
    it.remove();
  }
}

Answer 3

另一种想法: 如果<代码>User 类别可由用户名独一无二地界定,如果你凌驾于<代码>上的平等<>/代码>,则有下列内容:

public boolean equals(Object arg0) {
    return this.name.equals(((user) arg0).name);
}

页: 1 用户,不通过清单加以更新。你可以做:

 list.remove(new User("John Doe"))

Answer 4

页: 1 在试图将物体从<代码>上删除时,同时修改<>。名单/编号。对这一例外的解释是,<代码>ArrayList的代号是故障处理器。例如,如果它发现在运行时期的收集工作已经修改,它将放弃一个例外(失败)。解决这一问题的方法是使用<代码>Iterator。

这里是一个简单的例子,表明你如何能够通过<条码>加以利用。清单,并在满足特定条件时删除:

List<User> list = new ...

for (Iterator<User> it = list.iterator(); it.hasNext(); ) {

    User user = it.next();
    if (user.getUserEmail().equals(currentUser.getUserEmail())) {
       it.remove();
    }
}

Answer 5

建议解决这一问题的方法是:

ArrayList<User> list = new ArrayList<User>();
list.add(new User("user1","password1"));
list.add(new User("user2","password2"));
list.add(new User("user3","password3"));
list.add(new User("user4","password4"));
Iterator<String> iter = list.iterator();
while (iter.hasNext()) 
{
    User user = iter.next();
    if(user.name.equals("user1"))
    {
        //Use iterator to remove this User object.
        iter.remove();
    }
}

Using Iterator to remove an object is more efficient than removing by simply typing ArrayList(Object) because it is more faster and 20% more time saving and a standard Java practice for Java Collections.

Answer 6

你可以:

loop over the list with an iterator
check if each item in your list is the right user (checking the name)
if it is, use the remove method of the iterator.

Answer 7

Just search through the ArrayList of objects you get from the user, and test for a name equal to the name you want to remove. Then remove that object from the list.

Answer 8

你们的法典可能认为:

List<User> users = new ArrayList<User>();

public void removeUser(String name){
    for(User user:users){
        if(user.name.equals(name)){
            users.remove(user);
        }
    }
}

Answer 9

ArrayList<User> userList=new ArrayList<>();
//load data

public void removeUser(String userName){
    for (User user: userList){
        if(user.getName()equals(userName)){
            userList.remove(user);
        }
    }
}

友情链接