需求

给之前的 release 任务添加规则，如果task name 是 release 那么输出正在release

代码

tasks.addRule("do when calling release") {
    String taskName ->
        if (taskName.startsWith('release')) {
            logger.quiet 'applying rule to the task'
        }
}

执行

//gradlew release
> Task :makeReleaseVersion
do task action ... ...
releaseVersion-prefix
releaseVersion-prefix

> Task :compileJava UP-TO-DATE
applying rule to the task

> Task :release
releasing the project...

如果使用 -i 参数，那么可以观察到，我们定义的rule会在编译时就被调用:

> Task :compileJava UP-TO-DATE
Resolving global dependency management for project 'demo'
//看这里:
applying rule to the task
Excluding []
Excluding []
Caching disabled for task ':compileJava' because:
  Build cache is disabled
Skipping task ':compileJava' as it is up-to-date.
:compileJava (Thread[Daemon worker Thread 4,5,main]) completed. Took 0.541 secs.
:processResources (Thread[Execution worker for ':',5,main]) started.

总结

我们可以运用rule，队代码进行一定的预处理，比如遇到参数 A 那么调用Task A，遇到参数 B 调用Task B