Groovy 2.4.7三级Map结构重构异常求助

需求说明 #

需要将如下三级Map结构：

[ 
    1: [ 
        Par1: [ Podpar1: [s: 'str1', time: 16], Podpar2: [s: 'str2', time: 16] ], 
        Par2: [ Podpar1: [s: 0, time: 16], Podpar2: [s: 0, time: 16] ] 
    ], 
    2: [ 
        Par1: [ Podpar1: [s: 'str3', time: 16], Podpar2: [s: 'str4', time: 16] ], 
        Par2: [ Podpar1: [s: 0, time: 16], Podpar2: [s: 0, time: 16] ] 
    ] 
]

转换为层级调整后的结构：

[ 
    1: [ 
        Podpar1: [ Par1: [s: 'str1', time: 16], Par2: [s: 0, time: 16] ], 
        Podpar2: [ Par1: [s: 'str2', time: 16], Par2: [s: 0, time: 16] ] 
    ], 
    2: [ 
        Podpar1: [ Par1: [s: 'str3', time: 16], Par2: [s: 0, time: 16] ], 
        Podpar2: [ Par1: [s: 'str4', time: 16], Par2: [s: 0, time: 16] ] 
    ] 
]

问题重现 #

尝试使用以下代码实现转换：

def res =  [ "1" : [ "Par1" : [ "Podpar1" : [ "s" : "str" , "time" : 16 ] , "Podpar2" : [ "s" : "str" , "time" : 16 ]], "Par2" : ["Podpar1" : ["s" : 0 ,"time" : 16] , "Podpar2" : ["s" : 0 , "time" : 16 ]], "2" : ["Par1" : ["Podpar1" : ["s" : "str1" ,"time" : 16] ,"Podpar2" : ["s" : "str1" ,"time" : 16]]], "Par2" : ["Podpar1" : ["s" : 0 ,"time" : 16 ] ,"Podpar2" : ["s" : 0 ,"time" : 16]]]]

def reconfMap = [:]
res.each { k, v ->
    reconfMap[k] = [:]
    def temppar = [:]
    def temppodpar = [:]
    v.each { park, parv ->
        parv.each { podpark, podparv ->
            temppar[park]=podparv
            temppodpar[podpark]= temppar
            reconfMap[k] = temppodpar
        }
    }
}

运行后出现元素覆盖问题，得到错误结果：

[1:[Podpar1:[Par1:[s:str2, time:16], Par2:[s:0, time:16]], Podpar2:[Par1:[s:str2, time:16], Par2:[s:0, time:16]]], 2:[Podpar1:[Par1:[s:str4, time:16], Par2:[s:0, time:16]], Podpar2:[Par1:[s:str4, time:16], Par2:[s:0, time:16]]]]

期望的正确结果为：

[1:[Podpar1:[Par1:[s:str1, time:16], Par2:[s:0, time:16]], Podpar2:[Par1:[s:str2, time:16], Par2:[s:0, time:16]]], 2:[Podpar1:[Par1:[s:str3, time:16], Par2:[s:0, time:16]], Podpar2:[Par1:[s:str4, time:16], Par2:[s:0, time:16]]]]

问题原因 #

代码中temppar是同一个Map引用，每次循环修改temppar[park]都会改变这个Map的内容，所有Podpar对应的temppar指向的都是同一个对象。当循环结束时，temppar中存储的是最后一次循环的Par值，导致所有Podpar的Par1都被覆盖为最后一个值。

解决代码 #

以下是修正后的代码，通过为每个Podpar创建独立的子Map避免引用覆盖：

def originalMap = [ 
    1: [ 
        Par1: [ Podpar1: [s: 'str1', time: 16], Podpar2: [s: 'str2', time: 16] ], 
        Par2: [ Podpar1: [s: 0, time: 16], Podpar2: [s: 0, time: 16] ] 
    ], 
    2: [ 
        Par1: [ Podpar1: [s: 'str3', time: 16], Podpar2: [s: 'str4', time: 16] ], 
        Par2: [ Podpar1: [s: 0, time: 16], Podpar2: [s: 0, time: 16] ] 
    ] 
]

def transformedMap = [:]

originalMap.each { topKey, parMap ->
    transformedMap[topKey] = [:]
    // 收集当前顶层Key下所有Podpar的键，确保不遗漏
    def allPodparKeys = parMap.values().collect { it.keySet() }.flatten().unique()
    
    allPodparKeys.each { podparKey ->
        // 为每个Podpar创建独立的Map，存储对应的Par值
        def podparEntry = [:]
        parMap.each { parKey, podparMap ->
            podparEntry[parKey] = podparMap[podparKey]
        }
        transformedMap[topKey][podparKey] = podparEntry
    }
}

println transformedMap

代码逻辑说明 #

• 遍历每个顶层Key，初始化对应的空Map用于存储转换后的数据
• 收集当前顶层Key下所有Podpar的键，确保不会遗漏任何Podpar项
• 对每个Podpar键，创建独立的子Map，遍历所有Par项，将对应Podpar的值存入该子Map
• 将构建好的Podpar子Map存入转换后的顶层Map中，保证每个Podpar对应的Par数据都是独立的，不会出现覆盖问题

内容的提问来源于stack exchange，提问作者dobtyimolodec