Gradle Exec：为什么它没有运行在配置阶段？

Question

这是我的：

task makeDirectoryStructure(type:Exec){

    description 'Creates directory structure .'

    commandLine 'mkdir'
    args '-p' ,'top_dir/sub_dir_1/sub_dir_2'
    println "This line is printed in configuration phase."
}

$gradle tasks

我希望mkdir在配置阶段运行，即我的目录结构应该形成，但没有发生。

然而，我得到了以下输出：

yogeshwardancharan@yogeshwardancharan-Lenovo-G570:~/android_learning_resources/gradle_resources/ud867/1.01-Exercise-RunYourFirstTask$ gradle tasks
This line is printed in configuration phase.
:tasks

------------------------------------------------------------
All tasks runnable from root project
------------------------------------------------------------

Build Setup tasks
-----------------
init - Initializes a new Gradle build. [incubating]
wrapper - Generates Gradle wrapper files. [incubating]

Help tasks
----------
components - Displays the components produced by root project '1.01-Exercise-RunYourFirstTask'. [incubating]
dependencies - Displays all dependencies declared in root project '1.01-Exercise-RunYourFirstTask'.
dependencyInsight - Displays the insight into a specific dependency in root project '1.01-Exercise-RunYourFirstTask'.
help - Displays a help message.
model - Displays the configuration model of root project '1.01-Exercise-RunYourFirstTask'. [incubating]
projects - Displays the sub-projects of root project '1.01-Exercise-RunYourFirstTask'.
properties - Displays the properties of root project '1.01-Exercise-RunYourFirstTask'.
tasks - Displays the tasks runnable from root project '1.01-Exercise-RunYourFirstTask'.

Other tasks
-----------
makeDirectoryStructure - Creates directory structure .

现在，在上面这行的输出打印中

$gradle makeDirectoryStructure

Answer 1

请查看AbstractExecTask，Exec从其继承。正如您所看到的，有很多getter和setter。在配置时发生的是只为这些字段设置值，而不是运行它们。所有设置的属性都将仅在用@taskaction注释的exec()方法被调用时使用-这在运行时发生。为什么println工作？它只是一个被调用的方法，与上面提到的setter完全相同--println只是具有可见的效果，而setter只是更改后面使用的属性。

每一项任务都有它的行动。不同之处在于，在配置阶段，只配置任务，并且在执行任务操作时使用此配置。