使用 Gradle 和 Kotlin 构建一个可自我执行的 jar [英] Building a self-executable jar with Gradle and Kotlin

问题描述

为了开始使用，我编写了一个简单的 kotlin 源文件和一个 gradle 脚本文件.但是我不知道如何将 main func 添加到清单中，以便 jar 可以自我执行.

I've written a simple kotlin source file in order to get started, and a gradle script file. But I can't figure out how to add the main func to the manifest, so that the jar could be self-executable.

这里是我的 build.gradle 脚本:

Here my build.gradle script :

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:0.9.66'
    }
}
apply plugin: "kotlin"
repositories {
    mavenCentral()
}
dependencies {
    compile 'org.jetbrains.kotlin:kotlin-stdlib:0.9.66'
}

jar {
    manifest {
        attributes 'Main-Class': 'com.loloof64.kotlin.exps.ExpsPackage'
    }
}

这是我的 com.loloof64.kotlin.exps.Multideclarations.kt

Here is my com.loloof64.kotlin.exps.Multideclarations.kt

package com.loloof64.kotlin.exps

class Person(val firstName: String, val lastName: String) {
    fun component1(): String {
        return firstName
    }
    fun component2(): String {
        return lastName
    }
}

fun main(args: Array < String > ) {
    val(first, last) = Person("Laurent", "Bernabé")
    println("First name : $first - Last name : $last")
}

当我从终端 (java -jar MYJar.jar) 启动 jar 时，我得到以下堆栈跟踪，说我缺少 kotlin 反射库类，实际上它们还没有添加到 jar 中.似乎我缺少最终 jar 中的 kotlin-compiler 工件类，以及 kotlin-stdlib 源，但我不知道如何适应 gradle 构建.

When I launch the jar from terminal (java -jar MYJar.jar) I get the following stacktrace, saying me that the kotlin reflection library classes are missing, and indeed they have not been added to the jar. It seems that I am missing the kotlin-compiler artifact classes from the final jar, and also the kotlin-stdlib sources, but I don't know how to adapt the gradle build.

$> java -jar build/libs/kotlin_exps.jar 

Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/reflect/jvm/internal/InternalPackage
    at com.loloof64.kotlin.exps.ExpsPackage.<clinit>(MultiDeclarations.kt)
Caused by: java.lang.ClassNotFoundException: kotlin.reflect.jvm.internal.InternalPackage
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 1 more

我使用的是 Kotlin 0.9.66 和 gradle 2.1

I am using Kotlin 0.9.66 and gradle 2.1

推荐答案

我找到了解决方法(感谢 MkYong 网站)

I've found the workaround (thanks to MkYong website)

1. gradle 脚本需要 kotlin-compiler 工件作为依赖项
2. gradle 脚本需要一种方法来收集所有 kotlin 文件并将它们放入 jar 中.

所以我得到了以下 gradle 脚本:

So i get with the following gradle script :

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
       classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.0.1-2'
    }
}

apply plugin: "kotlin"

repositories {
    mavenCentral()
}

dependencies {
    compile 'org.jetbrains.kotlin:kotlin-stdlib:1.0.1-2'
}

jar {
    manifest {
        attributes 'Main-Class': 'com.loloof64.kotlin.exps.MultideclarationsKT'
    }

    // NEW LINE HERE !!!
    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
}

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