java - 将 JSON Builder 与集合结合使用

Question

我有这个代码:

    // Write metadate.json
    def jsonBuilder = new groovy.json.JsonBuilder()
    List myTemplateFilesList = new ArrayList();

    def myTemplate = new MyTemplate(module: ''+module,
            version: ''+version,
            unit: ''+unit,
            defaultPropertiesTargetPath: ''+targetPath)
    myTemplateFilesList.add(myTemplate);
    for (String key : keys) {
        def myTemplateFiles = new MyTemplateFiles(templateName: key,
                templateFileName: key+'.ht',
                targetFileName: key+'{{env}}{{client}}')
        myTemplateFilesList.add(myTemplateFiles);
    }
    jsonBuilder('templateFiles': myTemplateFilesList);
    println(jsonBuilder.toPrettyString())

class MyTemplate{
    def module
    def version
    def unit
    def defaultPropertiesTargetPath
}

class MyTemplateFiles{
    def templateName
    def templateFileName
    def targetFileName
}

我的输出:

{
    "templateFiles": [
        {
            "unit": "WAS-WDI",
            "version": "20_2",
            "defaultPropertiesTargetPath": "defaultPropertiesTargetPath:{{user.home}}/{{component}}/deployments/{{module}}/properties",
            "module":  "wdiCore"
        },
        {
            "templateFileName": "EnvWDI.ht",
            "templateName": "EnvWDI",
            "targetFileName": "EnvWDI{{env}}{{client}}"
        },
        {
            "templateFileName": "WDIHealthCheck.ht",
            "templateName": "WDIHealthCheck",
            "targetFileName": "WDIHealthCheck{{env}}{{client}}"
        },
        {
            "templateFileName": "CachesWDI.ht",
            "templateName": "CachesWDI",
            "targetFileName": "CachesWDI{{env}}{{client}}"
        },
        {
            "templateFileName": ".ht",
            "templateName": "",
            "targetFileName": "{{env}}{{client}}"
        }
    ] }

但我想要这个输出:

{
  "module": "wdiCore",
  "version": "20.1.1.0",
  "unit": "WAS-WDI",
  "defaultPropertiesTargetPath":"{{user.home}}/{{component}}/deployments/{{module}}/properties",
  "templateFiles" : 
  [
    { 
      "templateName": "EnvWDI" ,
      "templateFileName": "EnvWDI.ht" , 
      "targetFileName": "EnvWDI{{env}}{{client}}"
    },
    { 
      "templateName": "WDIHealthCheck{env}{client}" ,
      "templateFileName": "WDIHealthCheck.ht" , 
      "targetFileName": "WDIHealthCheck{{env}}{{client}}"
    },
    { 
      "templateName": "CachesWDI" ,
      "templateFileName": "CachesWDI.ht" , 
      "targetFileName": "CachesWDI{{env}}{{client}}",
      "targetPath":"{{user.home}}/{{component}}/properties/cache"
    }
  ]

}

我的代码有什么问题..？

Answer 1

首先，我必须假设您所需的输出部分包含拼写错误。我期望以下行:

      "templateName": "WDIHealthCheck{env}{client}" ,

实际上应该是:

      "templateName": "WDIHealthCheck" ,

对吗？

解决方案 1:定义 Groovy 对象以反射(reflect) JSON 结构

基本上，您只需使 Groovy 类看起来像您想要生成的 JSON 即可。那么让我们从顶部开始。您希望 JSON 对象的顶层包含 module、version、unit、defaultPropertiesTargetPath 和列表templateFiles。让我们在 Groovy 中定义该结构:

class MyTemplate{
    def module
    def version
    def unit
    def defaultPropertiesTargetPath
    List templateFiles
}

现在，该列表中有更多对象，所有对象都具有大致相同的结构。让我们在 Groovy 中定义该结构:

class MyTemplateFiles {
    def templateName
    def templateFileName
    def targetFileName
}

但这还不是全部，因为有一个带有附加属性的特殊情况:

class MySpecialTemplateFiles extends MyTemplateFiles {
    def targetPath
}

然后您的脚本代码如下所示(记住将 targetPath 属性添加到特殊情况):

List myTemplateFilesList = new ArrayList()
def myTemplate = new MyTemplate(
        module: module,
        version: version,
        unit: unit,
        defaultPropertiesTargetPath: targetPath)
// add the list to the template, not the other way around
myTemplate.templateFiles = myTemplateFilesList
for (String key : keys) {
    def myTemplateFiles
    // isolates special case
    if (key == "CachesWDI") {
        myTemplateFiles = new MySpecialTemplateFiles(
                templateName: key,
                templateFileName: key+'.ht',
                targetFileName: key+'{{env}}{{client}}',
                targetPath: "{{user.home}}/{{component}}/properties/cache")
    } else {
        myTemplateFiles = new MyTemplateFiles(
                templateName: key,
                templateFileName: key+'.ht',
                targetFileName: key+'{{env}}{{client}}')
    }
    myTemplateFilesList.add(myTemplateFiles)
}
// use template to instantiate jsonBuilder
def jsonBuilder = new groovy.json.JsonBuilder(myTemplate)
println(jsonBuilder.toPrettyString())

这会产生以下输出:

{
    "unit": "WAS-WDI",
    "version": "20.1.1.0",
    "defaultPropertiesTargetPath": "{{user.home}}/{{component}}/deployments/{{module}}/properties",
    "templateFiles": [
        {
            "templateFileName": "EnvWDI.ht",
            "templateName": "EnvWDI",
            "targetFileName": "EnvWDI{{env}}{{client}}"
        },
        {
            "templateFileName": "WDIHealthCheck.ht",
            "templateName": "WDIHealthCheck",
            "targetFileName": "WDIHealthCheck{{env}}{{client}}"
        },
        {
            "targetPath": "{{user.home}}/{{component}}/properties/cache",
            "templateFileName": "CachesWDI.ht",
            "templateName": "CachesWDI",
            "targetFileName": "CachesWDI{{env}}{{client}}"
        }
    ],
    "module": "wdiCore"
}

JSON 对象中的属性是无序的，因此这相当于您想要的输出。

解决方案 2:通过 JsonBuilder DSL 定义 JSON

无需在 Groovy 中定义类，而是使用 JsonBuilder 领域特定语言 (DSL) 直接定义 JSON 对象。在下面，我重命名了一些假定的输入，以避免命名冲突(module => myModule、unit => myUnit 等):

def jsonBuilder = new groovy.json.JsonBuilder()
jsonBuilder {
    module myModule
    version myVersion
    unit myUnit
    defaultPropertiesTargetPath myTargetPath
    // the following produces a list of maps for the templateFiles property
    templateFiles keys.collect { key ->
        def map = [
            templateName: key,
            templateFileName: key+'.ht',
            targetFileName: key+'{{env}}{{client}}']
        if (key == "CachesWDI") {
            map.targetPath = "{{user.home}}/{{component}}/properties/cache"
        }
        map
    }
}
println(jsonBuilder.toPrettyString())

该程序会产生您想要的确切输出。