Gradle：强制自定义任务始终运行（无缓存）

Question

我写了一个自定义的Gradle任务来处理路径可配置的文件系统上的一些依赖关系解析。我想要这种类型的任务总是运行。看起来虽然他们只运行一次，但我猜测是因为输入似乎没有改变。

我知道使用configurations { resolutionStrategy.cacheChangingModulesFor 0, 'seconds' }有效地禁用缓存，但我只希望它适用于非常具体的任务。也知道--rerun-tasks命令行提示符，这也是类似的。既不觉得最好的解决方案，也必须在自定义任务定义中正确设置它。

追随者是我目前的实施。我之前也有一个版本，其中前3个def String语句是@Input注释的String声明。

class ResolveProjectArchiveDependency extends DefaultTask { 
    def String archiveFilename = "" 
    def String relativeArchivePath = "" 
    def String dependencyScope = "" 

    @OutputFile 
    File outputFile 

    @TaskAction 
    void resolveArtifact() { 
     def arcFile = project.file("dependencies/"+dependencyScope+"/"+archiveFilename) 
     def newArcFile = "" 

     if(project.hasProperty('environmentSeparated') && project.hasProperty('separatedDependencyRoot')){ 
      println "Properties set denoting the prerelease environment is separated" 
      newArcFile = project.file(project.ext.separatedDependencyRoot+relativeArchivePath+archiveFilename) 
     } else { 
      newArcFile = project.file('../../'+relativeArchivePath+archiveFilename) 
     } 

     if(!newArcFile.isFile()){ 
      println "Warn: Could not find the latest copy of " + archiveFilename + ".." 

      if(!arcFile.isFile()) { 
       println "Error: No version of " + archiveFilename + " can be found" 
       throw new StopExecutionException(archiveFilename +" missing") 
      } 
     } 

     if(!arcFile.isFile()) { 
      println archiveFilename + " jar not in dependencies, pulling from archives" 
     } else { 
      println archiveFilename + " jar in dependencies. Checking for staleness" 

      def oldHash = generateMD5(new File(arcFile.path)) 
      def newHash = generateMD5(new File(newArcFile.path)) 

      if(newHash.equals(oldHash)) { 
       println "Hashes for the jars match. Not pulling in a copy" 
       return 
      } 
     } 

     //Copy the archive 
     project.copy { 
      println "Copying " + archiveFilename 
      from newArcFile 
      into "dependencies/"+dependencyScope 
     } 
    } 

    def generateMD5(final file) { 
     MessageDigest digest = MessageDigest.getInstance("MD5") 
     file.withInputStream(){is-> 
     byte[] buffer = new byte[8192] 
     int read = 0 
      while((read = is.read(buffer)) > 0) { 
       digest.update(buffer, 0, read); 
      } 
     } 
     byte[] md5sum = digest.digest() 
     BigInteger bigInt = new BigInteger(1, md5sum) 
     return bigInt.toString(16) 
    } 
} 

这里的任务使用的例子：

task handleManagementArchive (type: com.moremagic.ResolveProjectArchiveDependency) { 
    archiveFilename = 'management.jar' 
    relativeArchivePath = 'management/dist/' 
    dependencyScope = 'compile/archive' 
    outputFile = file('dependencies/'+dependencyScope+'/'+archiveFilename) 
} 

Answer 1

您可以通过在任务设置outputs.upToDateWhen { false }实现这一目标。

这可以在build.gradle文件执行：

handleManagementArchive.outputs.upToDateWhen { false } 

它也可以在您的自定义任务的构造函数来完成。

ResolveProjectArchiveDependency() { 
    outputs.upToDateWhen { false } 
}