如何在不覆盖当前条目的情况下添加多个 Groovy 映射条目? [英] How do I add multiple Groovy map entries without overwriting the current entries?

问题描述

我对 Groovy Maps 的问题.我一直在寻找一种以编程方式将新条目添加到 Groovy 映射而不覆盖当前条目的方法.例如

My question with Groovy Maps. I've been searching for a way to programmatically add a new entry to a Groovy map without overwriting the current entry. For example

def editsMap = [:]

lineEdits.flag.each 
{ lineEdits_Flag ->
   editsMap.put('FlagId',lineEdits_Flag.id)
   editsMap.put('FlagMnemonic',lineEdits_Flag.mnemonic)
   editsMap.put('Action',lineEdits_Flag.action)   
   println "editsMap: ${editsMap}"
}

第一遍产生这张地图:
editsMap: [FlagId:10001, FlagMnemonic:TRA, Action:review]

The first pass produces this map:
editsMap: [FlagId:10001, FlagMnemonic:TRA, Action:review]

但是第二遍覆盖了第一遍:editsMap: [FlagId:10002, FlagMnemonic:REB, Action:deny]

But the second pass overwrites the first pass with: editsMap: [FlagId:10002, FlagMnemonic:REB, Action:deny]

我想做的是在一张地图中创建多个条目.我需要我的地图来填充这样的东西:

What I'm trying to do is create multiple entries within the one map. I need my map to populate something like this:

editsMap: [FlagId:10001, FlagMnemonic:TRA, Action:review]
editsMap: [FlagId:10002, FlagMnemonic:REB, Action:deny]
editsMap: [FlagId:10003, FlagMnemonic:UNB, Action:deny]
editsMap: [FlagId:20001, FlagMnemonic:REB, Action:deny]
editsMap: [FlagId:20002, FlagMnemonic:ICD, Action:review]
editsMap: [FlagId:30001, FlagMnemonic:REB, Action:deny]
editsMap: [FlagId:40001, FlagMnemonic:ICD, Action:review]
editsMap: [FlagId:40002, FlagMnemonic:MPR, Action:review]
editsMap: [FlagId:50001, FlagMnemonic:CPT, Action:deny]
editsMap: [FlagId:60001, FlagMnemonic:DTU, Action:deny]
editsMap: [FlagId:70001, FlagMnemonic:ICD, Action:review]
editsMap: [FlagId:70002, FlagMnemonic:MPR, Action:review]

填充地图后，我需要能够找到某些值才能处理消息.我相信我可以使用类似的东西:

Once I have populated my map then I need to be able to find certain values in order to process a message. I believe that I can use something like:

def thisValue = appliedEditsMap[FlagId, '10001'] ?: "default"

进行快速查找.

有人可以帮助我了解如何以编程方式向 Groovy 映射添加值而不覆盖映射中已有的值吗?

Can someone help me understand how to programmatically add values to a Groovy map without overwriting the values already in the map?

推荐答案

你想要Guava 的 MultiMap:

Multimap<String, String> myMultimap = ArrayListMultimap.create();

// Adding some key/value
myMultimap.put("Fruits", "Bannana");
myMultimap.put("Fruits", "Apple");
myMultimap.put("Fruits", "Pear");
myMultimap.put("Vegetables", "Carrot");

// Getting values
Collection<string> fruits = myMultimap.get("Fruits");
System.out.println(fruits); // [Bannana, Apple, Pear]

这家伙对 Multimap 进行了纯 Groovy 模拟:

This guy makes a pure Groovy emulation of Multimap:

class GroovyMultimap {
    Map map = [:]

    public boolean put(Object key, Object value) {
        List list = map.get(key, [])
        list.add(value)
        map."$key" = list
    }
}

您可以在地图操作中使用 putAt 和 getAt 作为语法糖.你也可以试试 mixin 在地图对象中.

You can use putAt and getAt for syntatic sugar in map operations. You can also try a mixin in a map object.

他还将 Groovy 与 Guava 的 multimap 结合使用:

He also uses Groovy with Guava's multimap:

List properties = ['value1', 'value2', 'value3']
Multimap multimap = list.inject(LinkedListMultimap.create()) {
    Multimap map, object ->
    properties.each {
        map.put(it, object."$it")
    }
    map
}
properties.each {
    assertEquals (multimap.get(it), list."$it")
}

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