在Groovy中将JSON解析为CSV

Question

我正在尝试将json文件解析为csv。你能帮忙吗？示例json：

{
   "expand": "schema,names",
   "startAt": 0,
   "maxResults": 50,
   "total": 21,
   "issues":    [
            {
         "expand": "operations,versionedRepresentations",
         "id": "217580",
         "self": "issue/217580",
         "key": "ART-4070",
         "fields": {"summary": "#[ART] Pre.3 Verification \\"S\\""}
      },
            {
         "expand": "operations,versionedRepresentations",
         "id": "217579",
         "self": "issue/217579",
         "key": "ART-4069",
         "fields": {"summary": "Verification \\"C\\""}
      },
            {
         "expand": "operations,versionedRepresentations",
         "id": "217577",
         "self": "issue/217577",
         "key": "ART-4068",
         "fields": {"summary": "#[ART] Enum type"}
      }
   ]
}

结果csv应如下所示：

key;summary
ART-4070;#[ART] Pre.3 Verification \"S\"
ART-4069;Verification \"C\"
ART-4068;#[ART] Enum type

我尝试过这样的代码：

import groovy.json.*

def jsonSlurper = new JsonSlurper()
def json = '''
{
   "expand": "schema,names",
   "startAt": 0,
   "maxResults": 50,
   "total": 21,
   "issues":    [
            {
         "expand": "operations,versionedRepresentations",
         "id": "217580",
         "self": "issue/217580",
         "key": "ART-4070",
         "fields": {"summary": "#[ART] Pre.3 Verification \\"S\\""}
      },
           {
         "expand": "operations,versionedRepresentations",
         "id": "217579",
         "self": "issue/217579",
         "key": "ART-4069",
         "fields": {"summary": "Verification \\"C\\""}
      },
            {
         "expand": "operations,versionedRepresentations",
         "id": "217577",
         "self": "issue/217577",
         "key": "ART-4068",
         "fields": {"summary": "#[ART] Enum type"}
      }
   ]
}
'''
def obj = jsonSlurper.parse(json)

def columns = obj.issues*.keySet().flatten().unique()

// remove nulls
def encode = { e -> e == null ? '' : e  }

// Print all the column names
println columns.collect { c -> encode( c ) }.join( ';' )

// create all the rows
println obj.issues.collect { row ->
    // A row at a time
    columns.collect { colName -> encode( row[ colName ] ) }.join( ';' )
}.join( '\n' )

但结果是错误的：

扩展；id；自身；键；字段操作，versionedRepresentations;217580;issue/217580;ART-4070;[summary:#ART Pre.3验证"S"]操作，versionedRepresentations;217579;issue/217579;ART-4069;summary:Verification "C“操作，versionedRepresentations;217577;issue/217577;ART-4068;[summary:#ART枚举类型]

如何从json文件中只提取我想要的内容？我只需要两列:键、摘要和它们的值。

Answer 1

您只想从您的问题列表中提取特定信息，并且您需要不同的策略来提取这些信息。因此，我将使用“配置”来描述提取(参见下面的地图config )。然后代码非常接近你的原始代码(提取了一些常见的代码等)

import groovy.json.*

def config = [ // header -> extractor
    "key": { it.key },
    "summary": { it.fields.summary }
]

def encode(e) { // help with nulls; quote the separator
    (e ?: "").replaceAll(";", "\\;")  
}

def csvLine(items) { // write items as "CSV"
    println(items.collect{ encode it }.join(";"))
}

// main
def obj = new JsonSlurper().parse("data.json" as File)
csvLine(config.keySet())
obj.issues.each{ issue ->
    csvLine(config.values().collect{ f -> f issue })
}