1.安装Gradle

https://gradle.org/install/

$ brew install gradle

将Gradle Path加入~/.bash_profile

$ export PATH=$PATH:/opt/gradle/gradle-4.10/bin

检查Gradle是否安装成功

$ gradle -v

------------------------------------------------------------
Gradle 4.10
------------------------------------------------------------

2.Create a library project

$ mkdir building-java-libraries
$ cd building-java-libraries
$ gradle init --type java-library

3.Build

$ ./gradlew build
> Task :compileJava
> Task :processResources NO-SOURCE
> Task :classes
> Task :jar
> Task :assemble
> Task :compileTestJava
> Task :processTestResources NO-SOURCE
> Task :testClasses

> Task :test
Picked up _JAVA_OPTIONS: -Xmx2048m -Xms512m

> Task :check
> Task :build

BUILD SUCCESSFUL in 12s
4 actionable tasks: 4 executed

PS: Jar project can not import aar dependency.