【轉載】Skip Building Project Dependencies

Friday, December 5, 2014

 

Gradle Goodness: Skip Building Project Dependencies

If we use Gradle in a multi-module project we can define project dependencies between modules. Gradle uses the information from the project dependencies to determine which tasks need to be run. For example if module B depends on module A and we want to build module B, Gradle will also build module A for us, because module B depends on it. But if we know for sure that module A is up to date and has not changed, we can also instruct Gradle to skip building module A, when we build module B.

Let's start with the following module structure, where each module depends on the module above it. So module services depends on common and module web depends on services:

.

├── common

├── services

└── web

When we want to build the service module we go to the services directory and execute the build task and we get the following output:

$ gradle build

:common:compileJava

:common:processResources

:common:classes

:common:jar

:services:compileJava

:services:processResources

:services:classes

:services:jar

:services:assemble

:services:compileTestJava

:services:processTestResources

:services:testClasses

:services:test

:services:check

:services:build

 

BUILD SUCCESSFUL

 

Total time: 8.013 secs

We see in the output that first the common module is build, because the services module depends on it. But if we work on this project and we know for sure the common module is up to date and has not changed since the last build (for example we didn't checkout new sources from version control or changed sources in the common module ourselves), then we can skip building the common module. We use the command line option -a or--no-rebuild to tell Gradle to skip project dependencies.

When we run the build task from the services directory using the command line option -a we get the following output:

$ gradle -a build

:services:compileJava

:services:processResources

:services:classes

:services:jar

:services:assemble

:services:compileTestJava

:services:processTestResources

:services:testClasses

:services:test

:services:check

:services:build

 

BUILD SUCCESSFUL

 

Total time: 5.626 secs

This time only the services module is build, which also speeds up the build proces. Still this should only be used if we know ourselves the project dependencies are up to date.

Written with Gradle 2.2.1.

 

11.2. 排除任務

11.2. Excluding tasks

你能夠用命令行選項-x來排除某些任務,讓咱們用上面的例子來示範一下.
You can exclude a task from being executed using the -x command-line option and providing the name of the task to exclude. Let's try this with the sample build file above.

 

例 11.2. 排除任務.
Example 11.2. Excluding tasks

gradle dist -x test的輸出結果.
Output of gradle dist -x test

> gradle dist -x test
:compile
compiling source
:dist
building the distribution

BUILD SUCCESSFUL

Total time: 1 secs

能夠看到,test任務並無被調用,即便他是dist任務的依賴. 同時test任務的依賴任務compileTest也沒有被調用,而像 compile被test和其它任務同時依賴的任務仍然會被調用.
You can see from the output of this example, that the test task is not executed, even though it is a dependency of the dist task. You will also notice that the test task's dependencies, such as compileTest are not executed either. Those dependencies of test that are required by another task, such ascompile , are still executed.

http://pkaq.github.io/gradledoc/docs/userguide/ch11/tutorial_gradle_command_line.html