Android 工具命令——Gradle学习day1基本的gradle命令

https://rainmonth.github.io/posts/A191994.html

摘要

通过本文，记录下gradle最基本的命令讲解。如创建gradle项目的方法、gradle基本命令以及gradle里面的基本概念等。

[TOC]

创建一个gradle项目

通过gradle init 命令

cd /Documents
mkdir gradle-demo1
cd gradle-demo1
# 工作目录准备完毕
# 输入gradle init
gradle init
# 会有如下输出：
Select type of project to generate:
  1: basic
  2: groovy-application
  3: groovy-library
  4: java-application
  5: java-library
  6: kotlin-application
  7: kotlin-library
  8: scala-library
Enter selection (default: basic) [1..8]

Select build script DSL:
  1: groovy
  2: kotlin
Enter selection (default: groovy) [1..2]

Project name (default: gradle-demo):
BUILD SUCCESSFUL in 1m 0s
2 actionable tasks: 2 executed

上面输出提示已经很清楚了，如果不想选择直接按enter

这样一个名为gradle-demo的项目就新建完成了，项目结构如下：

├── build.gradle  
├── gradle
│   └── wrapper
│       ├── gradle-wrapper.jar  
│       └── gradle-wrapper.properties  
├── gradlew  
├── gradlew.bat  
└── settings.gradle  

常用命令

• 通过./gradlew tasks来查看Task，
• 通过./gradlew properties来查看项目的基础属性
• 通过./gradlew 具体Task名 --scan 可以在gradle提供调试网站上查看task运行的具体信息

常用option

首先，gradle有众多的option，可以输入gradle —help查看具体帮助，而且都有详细的解释说明

USAGE: gradle [option...] [task...]

-?, -h, --help            Shows this help message.
-a, --no-rebuild          Do not rebuild project dependencies.
-b, --build-file          Specify the build file.
--build-cache             Enables the Gradle build cache. Gradle will try to reuse outputs from previous builds.
-c, --settings-file       Specify the settings file.
--configure-on-demand     Configure necessary projects only. Gradle will attempt to reduce configuration time for large multi-project builds. [incubating]
--console                 Specifies which type of console output to generate. Values are 'plain', 'auto' (default), 'rich' or 'verbose'.
--continue                Continue task execution after a task failure.
-D, --system-prop         Set system property of the JVM (e.g. -Dmyprop=myvalue).
-d, --debug               Log in debug mode (includes normal stacktrace).
--daemon                  Uses the Gradle Daemon to run the build. Starts the Daemon if not running.
--foreground              Starts the Gradle Daemon in the foreground.
-g, --gradle-user-home    Specifies the gradle user home directory.
-I, --init-script         Specify an initialization script.
-i, --info                Set log level to info.
--include-build           Include the specified build in the composite.
-m, --dry-run             Run the builds with all task actions disabled.
--max-workers             Configure the number of concurrent workers Gradle is allowed to use.
--no-build-cache          Disables the Gradle build cache.
--no-configure-on-demand  Disables the use of configuration on demand. [incubating]
--no-daemon               Do not use the Gradle daemon to run the build. Useful occasionally if you have configured Gradle to always run with the daemon by default.
--no-parallel             Disables parallel execution to build projects.
--no-scan                 Disables the creation of a build scan. For more information about build scans, please visit https://gradle.com/build-scans.
--offline                 Execute the build without accessing network resources.
-P, --project-prop        Set project property for the build script (e.g. -Pmyprop=myvalue).
-p, --project-dir         Specifies the start directory for Gradle. Defaults to current directory.
--parallel                Build projects in parallel. Gradle will attempt to determine the optimal number of executor threads to use.
--priority                Specifies the scheduling priority for the Gradle daemon and all processes launched by it. Values are 'normal' (default) or 'low' [incubating]
--profile                 Profile build execution time and generates a report in the <build_dir>/reports/profile directory.
--project-cache-dir       Specify the project-specific cache directory. Defaults to .gradle in the root project directory.
-q, --quiet               Log errors only.
--refresh-dependencies    Refresh the state of dependencies.
--rerun-tasks             Ignore previously cached task results.
-S, --full-stacktrace     Print out the full (very verbose) stacktrace for all exceptions.
-s, --stacktrace          Print out the stacktrace for all exceptions.
--scan                    Creates a build scan. Gradle will emit a warning if the build scan plugin has not been applied. (https://gradle.com/build-scans)
--status                  Shows status of running and recently stopped Gradle Daemon(s).
--stop                    Stops the Gradle Daemon if it is running.
-t, --continuous          Enables continuous build. Gradle does not exit and will re-execute tasks when task file inputs change.
--update-locks            Perform a partial update of the dependency lock, letting passed in module notations change version. [incubating]
-v, --version             Print version info.
-w, --warn                Set log level to warn.
--warning-mode            Specifies which mode of warnings to generate. Values are 'all', 'summary'(default) or 'none'
--write-locks             Persists dependency resolution for locked configurations, ignoring existing locking information if it exists [incubating]
-x, --exclude-task        Specify a task to be excluded from execution.

Task相关

task的特点

其实gradle中Task相关的定义都在AbstractTask.java这个类中有定义，如常见的：

doFirst、doLast、dependsOn等

几点说明：

• lazy dependsOn，即被依赖的task无需提前声明

  task taskA {
    dependsOn 'taskB'
    doLast {
      println 'taskA'
    }
  }
  
  task taskB {
    doLast {
      println 'taskB'
    }
  }

  上面演示的就是taskA依赖于taskB，但taskB的声明在taskA之后

• dynamic Tasks，即可以动态的添加Tasks

  task dynamicTasks {
      4.times { counter ->
          task "task$counter" {
              doLast {
                  println "I'm task number $counter"
              }
          }
      }
  }

  上面的dynamicTasks运行后，会生成4个task，分别是task0、task1、task2、task3，且都可以单独运行

task的定义与创建

task有如下可以用如下几种方式定义与创建

# 方式1
task taskName {
  doLast {
    ...
  }
}
#方式2
task('taskname') {
  doLast {
    ...
  }
}
#方式3
task('copy', type: Copy) {
  from(file('srcDir'))
  into(buildDir)
}
#方法4 采用task 容器
tasks.create('hello') {
  doLast {
    ...
  }
}
tasks.create('copy', Copy) {
  doLast {
    ...
  }
}

task的访问与获取

可以采用以下方法访问task

#方式1 通过Project的属性来访问
task hello 
task copy(type: Copy)

println hello.name(or println project.hello.name)
println copy.destinationDir(or println project.copy.destinationDir)

#方式2 通过task container

println tasks.hello.name
println tasks.named('hello').get().name

println tasks.copy.destinationDir
pringln tasks.named('copy').get().destinationDir

#方式3 通过task container的getByPath(param)方法 param 可以穿task的名称、task的相对路径或者task的绝对路径
project(':projectA') {
  task hello
}

task hello

println tasks.getByPath('hello').path
println tasks.getByPath(':hello').path
println tasks.getByPath('projectA:hello').path
println tasks.getByPath(':projectA:hello').path

task的配置

先创建一个没有默认行为的copy task

task myCopy(type: Copy)

1. 使用gradle提供的Api配置

   Copy myCopy = tasks.getByName("myCopy")
   myCopy.from 'resources'
   myCopy.info 'target'
   myCopy.include('**/*.txt', '**/*.xml', '**/*.properties')

   将resources目录下面所有以.txt、.xml、.properties结尾的文件拷贝到target目录

2. 使用DSL规范语法来配置

   myCopy {
     from 'resources'
     into 'target'
     # 直接添加到这里也可以
   #  include('**/*.txt', '**/*.xml', '**/*.properties')
   }
   myCopy.include('**/*.txt', '**/*.xml', '**/*.properties')

向task的构造函数中传参

这里遇到了点问题，直接在demo中添加@Inject注解时找不到

task的操作

这里的操作主要是指task的提供的一些API操作

动态添加依赖

4.times { counter ->
    task "task$counter" {
      doLast {
        println "I'm task number $counter"
    }
  }
}
# task 0 依赖于task2和task3的运行
task0.dependsOn task2, task3

此时运行task0，会先运行task2和task3，在运行task0

动态添加某些行为

task hello {
  doLast {
    println 'Hello doLast'
  }
}
hello.doFirst {
  println 'Hello doFirst'
}
hello.configure {
  doLast {
    println "Hello doLast by configure first time"
  }
}
hello.configure {
  doLast {
    println 'Hello doLast by configure second time'
  }
}

注意doFirst执行在doLast之前，多个doLast执行循序按其在加入Action列表的循序执行

快捷的获取task的属性

在一个task中可以很方便的获取另一个已经定义好的task的属性

task anotherHello {
  doLast {
    println "another hello got hello task's name, is $hello.name"
  }
}

注意这里要用双引号

为task添加属性

可以为一个task添加自定义属性

task myTask {
  ext.myProperty = "myValue"
}
task printTaskProperties {
  doLast {
    println myTask.myProperty
  }
}

task的额外属性的添加是没有限制的，只要你想，你可以添加任意多的自定义属性