Gradle - 运行构建

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Gradle 提供了一个命令行来执行构建脚本。它一次可以执行多个任务。本章介绍如何使用不同选项执行多个任务。

执行多个任务

您可以从单个构建文件执行多个任务。Gradle 可以使用 gradle 命令处理构建文件。此命令将按照列出的顺序编译每个任务，并使用不同的选项执行每个任务以及依赖项。

例子

有四个任务 - task1、task2、task3和task4。任务 3 和任务 4 依赖于任务 1 和任务 2。看一下下图。

上述4个任务相互依赖，用箭头符号表示。看一下下面的代码。复制粘贴到build.gradle文件即可。

task task1 << {
   println 'compiling source'
}

task task2(dependsOn: task1) << {
   println 'compiling unit tests'
}

task task3(dependsOn: [task1, task2]) << {
   println 'running unit tests'
}

task task4(dependsOn: [task1, task3]) << {
   println 'building the distribution'
}

您可以使用以下代码来编译和执行上述任务。

C:\> gradle task4 test

输出

输出如下：

:task1
compiling source
:task2
compiling unit tests
:task3
running unit tests
:task4
building the distribution

BUILD SUCCESSFUL

Total time: 1 secs

排除任务

从执行中排除任务时，您可以将 –x 选项与 Gradle 命令一起使用，并提及要排除的任务的名称。

使用以下命令从上述脚本中排除 task4。

C:\> gradle task4 -x test

输出

下面引用的是代码的输出 -

:task1
compiling source
:task4
building the distribution

BUILD SUCCESSFUL

Total time: 1 secs

继续构建

一旦任何任务失败，Gradle 将中止执行并使构建失败。即使发生故障，您也可以继续执行。为此，您必须将 –continue 选项与 gradle 命令一起使用。它单独处理每个任务及其依赖性。

要点是它将捕获每个遇到的失败并在构建执行结束时报告。假设，如果一个任务失败，那么相关的后续任务也将不会被执行。

选择要执行的构建

当您运行 gradle 命令时，它会在当前目录中查找构建文件。您可以使用 –b 选项来选择特定的构建文件以及绝对路径。

以下示例从myproject.gradle文件中选择项目 hello ，该文件位于subdir/中。

task hello << {
   println "using build file '$buildFile.name' in '$buildFile.parentFile.name'."
}

您可以使用以下命令来执行上述脚本。

C:\> gradle -q -b subdir/myproject.gradle hello

输出

这会产生以下输出 -

using build file 'myproject.gradle' in 'subdir'.

获取构建信息

Gradle 提供了几个内置任务，用于检索有关任务和项目的详细信息。这对于理解构建的结构、依赖关系以及调试问题很有用。

您可以使用项目报告插件将任务添加到您的项目中，这将生成这些报告。

上市项目

您可以使用gradle –qprojects命令列出所选项目及其子项目的项目层次结构。使用以下命令列出构建文件中的所有项目。这是例子，

C:\> gradle -q projects

输出

输出如下：

------------------------------------------------------------
Root project
------------------------------------------------------------

Root project 'projectReports'
+--- Project ':api' - The shared API for the application
\--- Project ':webapp' - The Web application implementation

To see a list of the tasks of a project, run gradle <project-path>:tasks
For example, try running gradle :api:tasks

该报告显示每个项目的描述（如果指定）。您可以使用以下命令来指定描述。将其粘贴到build.gradle文件中。

description = 'The shared API for the application'

列出任务

您可以使用以下命令列出属于多个项目的所有任务。

C:\> gradle -q tasks

输出

输出如下：

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

Default tasks: dists

Build tasks
-----------
clean - Deletes the build directory (build)
dists - Builds the distribution
libs - Builds the JAR

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

Help tasks
----------
buildEnvironment - Displays all buildscript dependencies declared in root project 'projectReports'.
components - Displays the components produced by root project 'projectReports'. [incubating]
dependencies - Displays all dependencies declared in root project 'projectReports'.
dependencyInsight - Displays the insight into a specific dependency in root project 'projectReports'.
help - Displays a help message.
model - Displays the configuration model of root project 'projectReports'. [incubating]
projects - Displays the sub-projects of root project 'projectReports'.
properties - Displays the properties of root project 'projectReports'.
tasks - Displays the tasks runnable from root project 'projectReports' 
   (some of the displayed tasks may belong to subprojects).

To see all tasks and more detail, run gradle tasks --all

To see more detail about a task, run gradle help --task <task>

您可以使用以下命令来显示所有任务的信息。

C:\> gradle -q tasks --all

输出

当您执行上述代码时，您应该看到以下输出 -

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

Default tasks: dists

Build tasks
-----------
clean - Deletes the build directory (build)
api:clean - Deletes the build directory (build)
webapp:clean - Deletes the build directory (build)
dists - Builds the distribution [api:libs, webapp:libs]
   docs - Builds the documentation
api:libs - Builds the JAR
   api:compile - Compiles the source files
webapp:libs - Builds the JAR [api:libs]
   webapp:compile - Compiles the source files

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

Help tasks
----------
buildEnvironment - Displays all buildscript dependencies declared in root project 'projectReports'.
api:buildEnvironment - Displays all buildscript dependencies declared in project ':api'.
webapp:buildEnvironment - Displays all buildscript dependencies declared in project ':webapp'.
components - Displays the components produced by root project 'projectReports'. [incubating]
api:components - Displays the components produced by project ':api'. [incubating]
webapp:components - Displays the components produced by project ':webapp'. [incubating]
dependencies - Displays all dependencies declared in root project 'projectReports'.
api:dependencies - Displays all dependencies declared in project ':api'.
webapp:dependencies - Displays all dependencies declared in project ':webapp'.
dependencyInsight - Displays the insight into a specific dependency in root project 'projectReports'.
api:dependencyInsight - Displays the insight into a specific dependency in project ':api'.
webapp:dependencyInsight - Displays the insight into a specific dependency in project ':webapp'.
help - Displays a help message.
api:help - Displays a help message.
webapp:help - Displays a help message.
model - Displays the configuration model of root project 'projectReports'. [incubating]
api:model - Displays the configuration model of project ':api'. [incubating]
webapp:model - Displays the configuration model of project ':webapp'. [incubating]
projects - Displays the sub-projects of root project 'projectReports'.
api:projects - Displays the sub-projects of project ':api'.
webapp:projects - Displays the sub-projects of project ':webapp'.
properties - Displays the properties of root project 'projectReports'.
api:properties - Displays the properties of project ':api'.
webapp:properties - Displays the properties of project ':webapp'.
tasks - Displays the tasks runnable from root project 'projectReports' 
   (some of the displayed tasks may belong to subprojects).
api:tasks - Displays the tasks runnable from project ':api'.
webapp:tasks - Displays the tasks runnable from project ':webapp'.

下面给出了命令列表以及说明。