如何将枚举类型存储到地图中？ [英] How do I store Enum types into a map?

问题描述

我正在尝试存储和检索一个枚举类，所以我可以稍后找到正确的类型（基于配置），并调用ValueOf来解析字符串。如何放置/获取然后调用ValueOf？

在伪代码中，它看起来像这样：

 枚举MyType {VAL1，VAL2}; 
枚举MyColors {BLUE，RED}; 
映射< String，Class> map = Maps.newHashMap（）; 
 map.put（key1，MyType.class）; //这是MyType枚举以上
 map.put（colors，MyColors.class）; //这是MyColors枚举以上
 ... 
 String inputType =colors; 
 String inputValue =BLUE; 
类c = map.get（inputType）; 
 assertEquals（MyColors.BLUE，c.ValueOf（inputValue））; //这里我想要MyColors.ValueOf（）来调用
 Class c2 = map.get（key1）; 
 assertEquals（MyType.VAL1，c.ValueOf（VAL1））; //这里我想要MyType.ValueOf（）来调用
  

我该怎么做？ p>

为了给我一些背景，为什么我这样做 - 我有多个这样的枚举类型，我得到一个输入，告诉我什么样的枚举（在文本中）和一个的枚举值，所以我想从地图中查找枚举类，然后调用正确解析的静态ValueOf。

注 - 我不想在地图中存储MyType对象，我想存储类引用

谢谢！

解决方案

您可以使用 java.lang.Enum.valueOf（Class enumType，String name）

  
 
枚举MyType {VAL1，VAL2}; 
映射enumMap = Maps.newHashMap（）; 
 map.put（key1，MyType.class）; 
 ... 
类c = map.get（key1）; 
 assertEquals（MyType.VAL1，Enum.valueOf（c，VAL1））; 
 
  

I am trying to store and retrieve an enum class so I can later find the correct type (based on configuration) and call ValueOf on it to parse a string. How do I put/get and then call the ValueOf?

In pseudo code it would look something like this:

enum MyType { VAL1, VAL2 };
enum MyColors { BLUE, RED };
Map<String, Class> map = Maps.newHashMap();
map.put("key1", MyType.class);      //this is the MyType enum above
map.put("colors", MyColors.class);  //this is the MyColors enum above
...
String inputType = "colors";
String inputValue = "BLUE";
Class c = map.get(inputType);
assertEquals(MyColors.BLUE, c.ValueOf(inputValue));  //here I want MyColors.ValueOf() to get called
Class c2 = map.get("key1");
assertEquals(MyType.VAL1, c.ValueOf("VAL1"));  //here I want MyType.ValueOf() to get called

How can I do this?

To give some background on why I am doing this - I have multiple such enum types and I get an input which tells me what kind of enum it is (in text) and one of the values from the enum, so I want to look up the enum class from the map and then call the static ValueOf on it which will parse correctly.

Note - I do not want to store MyType objects in the map, I want to store class references

Thanks!

解决方案

You can use java.lang.Enum.valueOf(Class enumType, String name)

    enum MyType { VAL1, VAL2 };
    Map enumMap = Maps.newHashMap();
    map.put("key1", MyType.class);
    ...
    Class c = map.get("key1");
    assertEquals(MyType.VAL1, Enum.valueOf(c, "VAL1"));

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