Gradle 运行Java Main 类

文章来源

翻译自 Run a Java main Method Using Gradle，尊重原创

可复制地址

简介

在这个教程中，我们将探索使用Gradle执行Java Main的不同的方法。

Java Main

打印到控制台

public class MainClass {
    public static void main(String[] args) {
        System.out.println("Goodbye cruel world ...");
    }
}

使用application插件运行

application插件官网文档

这个插件是一个核心的Gradle插件，他定义了一系列线程的任务，帮助我们打包盒分发应用程序。

build.gradle

plugins {
    id "application"
}
apply plugin : "java" 
ext {
   javaMainClass = "com.baeldung.gradle.exec.MainClass"
}

application {
    mainClassName = javaMainClass
}

该插件会自动生成一个名为run的任务，主需要将其指向主类即可

运行命令

~/work/baeldung/tutorials/gradle-java-exec> ./gradlew run

> Task :run
Goodbye cruel world ...

BUILD SUCCESSFUL in 531ms
2 actionable tasks: 1 executed, 1 up-to-date

利用 JavaExec 任务执行

JavaExec官方文档

利用 JavaExec 任务类型运行主类

task runWithJavaExec(type: JavaExec) {
    group = "Execution"
    description = "Run the main class with JavaExecTask"
    classpath = sourceSets.main.runtimeClasspath
    main = javaMainClass
}

运行命令

~/work/baeldung/tutorials/gradle-java-exec> ./gradlew runWithJavaExec

> Task :runWithJavaExec
Goodbye cruel world ...

BUILD SUCCESSFUL in 526ms
2 actionable tasks: 1 executed, 1 up-to-date

利用 Exec 任务

Exec官方文档

从编译构建输出运行

任务

task runWithExec(type: Exec) {
    dependsOn build
    group = "Execution"
    description = "Run the main class with ExecTask"
    commandLine "java", "-classpath", sourceSets.main.runtimeClasspath.getAsPath(), javaMainClass
}

运行命令

~/work/baeldung/tutorials/gradle-java-exec> ./gradlew runWithExec

> Task :runWithExec
Goodbye cruel world ...

BUILD SUCCESSFUL in 666ms
6 actionable tasks: 6 executed

编译成.class 运行

任务

task runWithExecJarOnClassPath(type: Exec) {
    dependsOn jar
    group = "Execution"
    description = "Run the mainClass from the output jar in classpath with ExecTask"
    commandLine "java", "-classpath", jar.archiveFile.get(), javaMainClass
}

运行

~/work/baeldung/tutorials/gradle-java-exec> ./gradlew runWithExecJarOnClassPath

> Task :runWithExecJarOnClassPath
Goodbye cruel world ...

BUILD SUCCESSFUL in 555ms
3 actionable tasks: 3 executed

编译成 .jar 运行

文件

jar {
    manifest {
        attributes(
            "Main-Class": javaMainClass
        )
    }
}

task runWithExecJarExecutable(type: Exec) {
    dependsOn jar
    group = "Execution"
    description = "Run the output executable jar with ExecTask"
    commandLine "java", "-jar", jar.archiveFile.get()
}

运行

~/work/baeldung/tutorials/gradle-java-exec> ./gradlew runWithExecJarExecutable

> Task :runWithExecJarExecutable
Goodbye cruel world ...

BUILD SUCCESSFUL in 572ms
3 actionable tasks: 3 executed