Gradle
著名构建工具，比 Maven 更快，更适合大型项目，配置更简洁
下载地址： https://gradle.org/install/
解压并配置环境变量
export GRADLE_HOME=/opt/gradle/gradle-8.4
export PATH=$PATH:$GRADLE_HOME/bin
export GRADLE_USER_HOME=/path/to/maven/repository
% gradle -v
------------------------------------------------------------
Gradle 8.4
------------------------------------------------------------
Build time: 2023-10-04 20:52:13 UTC
Revision: e9251e572c9bd1d01e503a0dfdf43aedaeecdc3f
Kotlin: 1.9.10
Groovy: 3.0.17
Ant: Apache Ant(TM) version 1.10.13 compiled on January 4 2023
JVM: 17.0.7 (Oracle Corporation 17.0.7+8-LTS-224)
OS: Mac OS X 13.3.1 x86_64
配置国内镜像
以腾讯镜像为例，编辑 init.d/init.gradle，寻找镜像会优先在本地 maven 仓库找，然后腾讯镜像，然后再到 maven 中央仓库
allprojects {
repositories {
mavenLocal()
maven {
url "https://mirrors.cloud.tencent.com/nexus/repository/maven-public/"
}
mavenCentral()
}
}
如果是 kts 则这样配置
maven { url = uri("https://mirrors.cloud.tencent.com/nexus/repository/maven-public/") }
目录结构
/build 类似 maven 的 target 目录，编译打包的文件
/gradle/wraper 封装包装器文件夹
/src 源代码，同 maven ，例如 java 项目在 /src/main/java 下写源代码，如果是 war 包，还会有 /src/main/webapp 目录
gradlew 包装器启动脚本
gradlew.bat windows 包装器启动脚本
build.gradle 构建脚本，类似 maven 的 pom.xml
settings.gradle 配置文件，定义项目和子项目名称信息
使用 gradle init 创建项目
% gradle init
Starting a Gradle Daemon (subsequent builds will be faster)
Select type of project to generate:
1: basic
2: application
3: library
4: Gradle plugin
Enter selection (default: basic) [1..4] 2
Select implementation language:
1: C++
2: Groovy
3: Java
4: Kotlin
5: Scala
6: Swift
Enter selection (default: Java) [1..6] 3
Generate multiple subprojects for application? (default: no) [yes, no]
Select build script DSL:
1: Kotlin
2: Groovy
Enter selection (default: Kotlin) [1..2] 1
Select test framework:
1: JUnit 4
2: TestNG
3: Spock
4: JUnit Jupiter
Enter selection (default: JUnit Jupiter) [1..4]
Project name (default: test): testproject
Source package (default: testproject): com.test
Enter target version of Java (min. 7) (default: 17):
Generate build using new APIs and behavior (some features may change in the next minor release)? (default: no) [yes, no] no
> Task :init
To learn more about Gradle by exploring our Samples at https://docs.gradle.org/8.4/samples/sample_building_java_applications.html
会自动生成一个 gradle 项目，并带一个主程序 app/src/main/java/com/test/App.java
package com.test;
public class App {
public String getGreeting() {
return "Hello World!";
}
public static void main(String[] args) {
System.out.println(new App().getGreeting());
}
}
将项目拖到 IntelliJ Idea 中运行，输出和 Maven 项目会有些不一样
20:22:19: Executing ':app:App.main()'...
> Task :app:compileJava
> Task :app:processResources NO-SOURCE
> Task :app:classes
> Task :app:App.main()
Hello World!
Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.
You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.
For more on this, please refer to https://docs.gradle.org/8.4/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.
BUILD SUCCESSFUL in 4s
2 actionable tasks: 2 executed
20:22:24: Execution finished ':app:App.main()'.
Intellij Idea 在创建新项目时也可以选择 gradle 项目。也会自动生成 src 目录，gradle/wrapper 文件夹，build.gradle.kts 脚本， gradlew 和 gradlew.bat 包装器。
gradle-wrapper.properties 添加配置使用国内源，不然下载可执行文件非常非常慢
#distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
distributionUrl=https\://mirrors.cloud.tencent.com/gradle/gradle-8.5-bin.zip
包装器第一次运行会下载可执行文件
% ./gradlew -v
Downloading https://services.gradle.org/distributions/gradle-8.4-bin.zip
............10%............20%.............30%............40%.............50%............60%.............70%............80%.............90%............100%
------------------------------------------------------------
Gradle 8.4
------------------------------------------------------------
Build time: 2023-10-04 20:52:13 UTC
Revision: e9251e572c9bd1d01e503a0dfdf43aedaeecdc3f
Kotlin: 1.9.10
Groovy: 3.0.17
Ant: Apache Ant(TM) version 1.10.13 compiled on January 4 2023
JVM: 17.0.7 (Oracle Corporation 17.0.7+8-LTS-224)
OS: Mac OS X 13.3.1 x86_64
查看 Gradle 任务
% gradle task
> Task :tasks
------------------------------------------------------------
Tasks runnable from root project 'testproject'
------------------------------------------------------------
Application tasks
-----------------
run - Runs this project as a JVM application
Build tasks
-----------
assemble - Assembles the outputs of this project.
build - Assembles and tests this project.
buildDependents - Assembles and tests this project and all projects that depend on it.
buildNeeded - Assembles and tests this project and all projects it depends on.
classes - Assembles main classes.
clean - Deletes the build directory.
jar - Assembles a jar archive containing the classes of the 'main' feature.
testClasses - Assembles test classes.
Build Setup tasks
-----------------
init - Initializes a new Gradle build.
wrapper - Generates Gradle wrapper files.
Distribution tasks
------------------
assembleDist - Assembles the main distributions
distTar - Bundles the project as a distribution.
distZip - Bundles the project as a distribution.
installDist - Installs the project as a distribution as-is.
Documentation tasks
-------------------
javadoc - Generates Javadoc API documentation for the 'main' feature.
Help tasks
----------
buildEnvironment - Displays all buildscript dependencies declared in root project 'testproject'.
dependencies - Displays all dependencies declared in root project 'testproject'.
dependencyInsight - Displays the insight into a specific dependency in root project 'testproject'.
help - Displays a help message.
javaToolchains - Displays the detected java toolchains.
kotlinDslAccessorsReport - Prints the Kotlin code for accessing the currently available project extensions and conventions.
outgoingVariants - Displays the outgoing variants of root project 'testproject'.
projects - Displays the sub-projects of root project 'testproject'.
properties - Displays the properties of root project 'testproject'.
resolvableConfigurations - Displays the configurations that can be resolved in root project 'testproject'.
tasks - Displays the tasks runnable from root project 'testproject' (some of the displayed tasks may belong to subprojects).
Verification tasks
------------------
check - Runs all checks.
test - Runs the test suite.
To see all tasks and more detail, run gradle tasks --all
To see more detail about a task, run gradle help --task <task>
BUILD SUCCESSFUL in 16s
1 actionable task: 1 executed
常见命令
gradle clean 清空 build 目录
gradle classes 编译业务代码和配置文件，编译后的文件在 build 目录下
gradle test 编译测试代码，生成测试报告
gradle build 构建项目
gradle build -x test 跳过测试构建
配置文件
不同于 Maven 通过配置文件来配置，Gradle 通过编写 Kotlin 或 Groovy 脚本调用 Gradle 的 Api 进行配置（其中 Kotlin 的配置文件带有 .kts）
settings.gradle.kts 用于配置项目
gradle 在 settings.gradle.kts 文件中提供了一个名为 settings 的 SettingsDelegate 对象，settings 可以省略，例如 ettings.rootProject.name 可以省略为 rootProject.name
rootProject.name 配置项目名称，include 配置子项目
rootProject.name = "project-name"
include("sub-project-1")
include("sub-project-2")
buid.gradle.kts
plugins 配置插件，如果是官方的插件不需要版本号，非官方的需要传入版本号，下方的语法是用 kotlin 中缀函数传递版本号
plugins {
//中缀函数，类似 id("org.springframework.boot").version("3.3.0")
id("org.springframework.boot") version "3.3.0"
id("io.spring.dependency-management") version "1.1.5"
id("java")
}
配置 java 插件
java {
toolchain {
languageVersion = JavaLanguageVersion.of(17)
}
}
repositories 配置仓库，mavenCentral 为 maven 中央仓库
repositories {
mavenCentral()
maven { url = uri("https://repo.spring.io/milestone") }
}
dependencies 配置依赖
implementation 配置依赖，testImplementation 配置测试需要的依赖
- implementation: 配置依赖
- testImplementation: 用于添加测试时需要的依赖项。
- compileOnly: 用于指定编译时依赖，但不会打包
- runtimeOnly：仅在运行时使用，不参与编译
依赖的 groupId artifactId version 通过冒号分隔，也可以用三个参数，不需要引入的间接依赖可以通过 exclude 除掉
dependencies {
implementation("org.springframework.boot:spring-boot-starter-web"){
exclude("groupId", "artifactId")
}
implementation("commons-io:commons-io:2.16.1")
testImplementation("org.springframework.boot:spring-boot-starter-test")
}