Antlr4-为gradle中的更多语言生成语法源

在我的项目中，我必须使用gradle为多种语言（Java、Javascript和Python）生成语法源

我正在使用antlr插件，因此我的build.gradle文件中有以下行：

apply plugin: 'antlr'

generateGrammarSource {
    def languageFlag = project.hasProperty('Language') ?project.property('Language') : 'Python2'

    arguments = ['-Dlanguage=' + languageFlag]

    def pythonOutputDirectory = "python/engine_lib/kpi_attributes"
    switch (languageFlag) {
        case "Java":    
            outputDirectory = file("../../../../XSpotterGUI/sviluppo/src/com/xech/xspotter4/grammars/kpiattributes")
            arguments += ['-package', 'com.xech.xspotter4.grammars.kpiattributes']
            break
        case "JavaScript":  
            outputDirectory = file("../../../../XSpotterGUI/sviluppo/WebContent/xspotter4/js/xech/grammars/kpiattributes")
            break
        case "Python2":
            outputDirectory = file(pythonOutputDirectory)
            break
    }
    description = 'Generates Java sources from Antlr4 grammars.'
    maxHeapSize = "64m"
    sourceSets.main.antlr.srcDirs = ['.']

    includes = ['KpiAttributes.g4']

    doLast {
        if (languageFlag.equals("Python2")) {
            File file = new File("$pythonOutputDirectory/__init__.py")
            file.write ""
        }    
    }
}

我省略了关于存储库、依赖项等的行

这样我就可以给gradle打三次电话：

./gradlew generateGrammarSource -PLanguage=Java
./gradlew generateGrammarSource -PLanguage=Python2
./gradlew generateGrammarSource -PLanguage=JavaScript

但我无法创建一个任务“GeneratealGrammarSources”，以便只调用一次gradlew并生成所有源