在迭代它时修改Java ArrayList [英] Modifying Java ArrayList while iterating over it

问题描述

我想做类似
的事情这

但是，我不希望迭代添加的元素。基本上我有一个潜在的arraylist，我在arraylist上返回一个迭代器。在使用该迭代器进行迭代时，我想将元素添加到原始的arraylist中。我该怎么做？

However, I do NOT want the added elements to be iterated over. Basically I have an underlying arraylist, and I return an iterator over the arraylist. While iterating using that iterator, I want to add elements to the original arraylist. How do I do this?

编辑：这个问题是我需要迭代代码修改的迭代器中的对象。我不认为克隆arraylist会起作用...

The problem with this is that I need the objects in the iterator modified by the iterating code. I don't think that cloning the arraylist will work...

EDIT2：这是我的代码的精简版。

Here is a stripped-down version of my code.

public class Map {
     // a bunch of code
     private ArrayList<Robot> robots;

     public Iterator<Robot> getRobots() {
          return robots.iterator();
     }

     public void buildNewRobot(params) {
          if(bunchOfConditions)
                robots.add(new Robot(otherParams);
     }

     // a bunch more code
}

这是地图正在另一个类中使用。

And here is the map being used in another class.

for(Iterator<Robot> it = map.iterator(); it.hasNext();){
   Robot r = it.next();
   // a bunch of stuff here
   // some of this code modifies Robot r 

   if(condition)
       map.buildNewRobot(params);
}

推荐答案

您可以创建列表的副本并迭代副本并将数据添加到旧副本。问题是您不会迭代新的itens。

You may create a copy of your list and iterate over the copy and add data to the old one. The problem is that you will not iterate over the new itens.

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