Java中的有序列表映射实现 [英] Ordered List Map implementation in Java

问题描述

我想知道是否有一个类在Java中实现了 Map 和 List 接口。

我有一个数据结构，主要是一个 Map 。我将字符串（ID）映射到图像 s。但是在我的代码的特定部分，我需要向用户显示所有可用的ID $ 图像。到目前为止，唯一的方法就是写下来：

  for（String id：myMap.keySet（））{
 //获取像这样的图像myMap.get（id）
} 
  

所以有一个类可以实现 Map 和 List ，所以我可以简单地写： / p>

  for（Image img：myMap）{
 //图像是img 
} 
有没有人知道这样的实现？ 

EDIT ：在查看答案（这些都是正确的，投了赞成票）后，我现在意识到我也需要将地图排序。当我说排序时，我的意思是，我希望它具有特定顺序的值，我可以修改。我知道这不是原来的问题，但我只是意识到我需要这个。

编辑2 ：似乎我犹豫不决。我需要的是一个有序的地图，而不是一个排序的地图。

解决方案

如果您按照特定顺序需要您的项目， LinkedHashMap 是您的朋友 - 它保留项目的插入顺序。 TreeMap将保持您的项目按照您给出的比较器或键的compareTo方法定义的顺序。

I was wondering if there is a class out there that implements both the Map and List interfaces in Java.

I have a data structure that is primarily a Map. I map strings (IDs) to Images. But in a specific part of my code, I need to present the user with all the available IDed Images. The only way to do that so far is to write this:

for (String id : myMap.keySet()) {
    // get the image like this "myMap.get(id)" 
}

So it would be nice to have a class that implements both Map and List so I could simply write:

for (Image img : myMap) {
  // the image is img
}

Does anyone know of such an implementation?

EDIT: After viewing the answers (which are all correct, voted up), I now realize I would also need the map to be sorted. When I say "sorted", all I mean is that I would like it to have the values in a specific order, one that I would be able to modify. I know this is not the original question, but I just realized that I need that.

EDIT 2: It seems I am indecisive. What I need is an ordered map, not a sorted one. Sorry for the confusion, people.

解决方案

If you need your items in a specific order, LinkedHashMap is your friend - it keeps items in insertion order. TreeMap will keep your items in an order defined by either a Comparator you give or a compareTo method of the key.

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