Develop Reference

External libraries are not found in the final build

I been working on a project that uses an external jar file. Whenever, I build my project using build.grade, and the external files does not get added to the final jar file. Inside my workspace, I have a "libs" folder which holds the external jar file (Discord Rich Presence). Can anyone help me sort this out?
buildscript {
repositories {
jcenter()
maven {
name = "forge"
url = "http://files.minecraftforge.net/maven"
}
}
dependencies {
classpath 'net.minecraftforge.gradle:ForgeGradle:2.1-SNAPSHOT'
}
}
apply plugin: 'net.minecraftforge.gradle.forge'
version = "1.0"
group= "com.yourname.modid"
archivesBaseName = "example"
minecraft {
version = "1.8.9-11.15.1.1722"
runDir = "run"
mappings = "stable_20"
}
repositories {
flatDir {
dirs "libs"
}
}
dependencies {
compile name: 'discord-rpc'
}
processResources {
inputs.property "version", project.version
inputs.property "mcversion", project.minecraft.version
from(sourceSets.main.resources.srcDirs) {
include 'mcmod.info'
expand 'version':project.version, 'mcversion':project.minecraft.version
}
from(sourceSets.main.resources.srcDirs) {
exclude 'mcmod.info'
}
}

The default task jar only packages the files of project source code. To include all the dependencies inside the JAR file, you could try https://plugins.gradle.org/plugin/com.github.johnrengelman.shadow:
plugins {
...
id "com.github.johnrengelman.shadow" version "7.0.0"
}
...
Run this command to package all:
$ ./gradlew shadowJar

Gradle: create a single JAR with dependencies

I am migrating our product's build from Ant to Gradle, having started from a single project and got the following error:
> Could not resolve all files for configuration ':Shared:serverbase:compileClasspath'.
> Could not find guava:guava:23.3-jre.
Searched in the following locations:
- https://jcenter.bintray.com/guava/guava/23.3-jre/guava-23.3-jre.pom
- file:/F:/pros/X/java/guava/guava-23.3-jre.xml
Required by:
project :Shared:serverbase
Why it is looking for xml-files instead of jar?
Here are my files:
build.gradle in project's root directory:
buildscript {
repositories {
jcenter()
maven {
url "https://plugins.gradle.org/m2/"
}
}
dependencies {
classpath 'de.richsource.gradle.plugins:gwt-gradle-plugin:0.6' // gwt compiler plugin
}
}
allprojects {
apply from: rootProject.file('libraries.gradle')
repositories {
jcenter()
ivy {
url "file://${rootProject.projectDir}/ThirdParty/java/"
patternLayout {
artifact "[organization]/[module](-[revision])(.[ext])"
}
}
}
}
subprojects {
apply plugin: 'java-library'
sourceCompatibility = '1.8'
targetCompatibility = '1.8'
compileJava.options.debugOptions.debugLevel = "lines,vars,source"
compileJava.options.compilerArgs += ["-nowarn"]
compileJava.options.debug = true
}
build.gradle of this single project:
sourceSets.main.java.srcDirs = ['src']
dependencies {
implementation "guava:guava:${guavaVersion}"
implementation "slf4j:jul-to-slf4j:${slf4jVersion}"
implementation "logback:logback-classic:${logbackVersion}"
}
jar {
manifest {
attributes 'Class-Path': configurations.compileClasspath.collect { it.getName() }.join(' ')
}
}
settings.gradle:
rootProject.name = 'X'
include 'Shared:serverbase'
libraries.gradle:
ext {
...
guavaVersion = '23.3-jre'
...
}
(some content stripped)
And if I add file dependency to build.gradle as local file (How to add local .jar file dependency to build.gradle file?)
implementation files("guava-${guavaVersion}.jar")
I got tons of errors like 'error: package org.slf4j does not exist' so it seems that dependencies were not satisfied at all.
The outcome should be a single jar with compiled sources.
I am a novice in gradle, please forgive my unenlightenment.

Your Guava dependency is not correct.
Change from:
implementation "guava:guava:${guavaVersion}"
To:
implementation "com.google.guava:guava:${guavaVersion}"

How to deploy a Jar from a library project

I have a library project in Java which is several folders, each one doing specific parts and having its own dependencies.
Since I am working locally I would like to deploy this library locally and get the Jar to import to another project.
For this reason I am using gradle and what I did was going to the directory where I have all the folders of the library and gradle init and then gradle build.
Since I want the files locally, I saw that I can use gradle publishToMavenLocal, which I did and it created a jar file under ~/.m2/..... Now the issue is that this jar file appear to only contain a META-INF folder and inside of it a manifest.mf file.
This is the build.gradle file used.
What am I doing wrong? Should I do something different?

check gradle docs
there is also a complete example.
be sure to add your sourceSets that you want to compile and build in the jar.
build.gradle
plugins {
id 'java'
id 'maven-publish'
}
repositories {
mavenLocal()
mavenCentral()
}
sourceCompatibility = 1.8
targetCompatibility = 1.8
sourceSets {
main {
java { srcDir 'src/main/java' }
resources {
srcDirs 'src/main/resources'
}
}
test {
java { srcDir 'src/test/java' }
resources {
srcDirs 'src/test/resources'
}
}
}
publishing {
publications {
maven(MavenPublication) {
groupId = 'org.gradle.sample'
artifactId = 'project1-sample'
version = '1.1'
from components.java
}
}
}
You could also add your library project to your main project like this :
build.gradle
dependencies {
compile project(':library_project')
}
settings.gradle
rootProject.name = 'Project'
include ":library_project"
project(':library_project').projectDir = new File(settingsDir, '../library_project')

using Kotlin with Gradle

I'm new to Kotlin and Gradle, and tried to follow these steps, so I got the following 2 files:
after running gradle init I changed the build.gradle to be:
// set up the kotlin-gradle plugin
buildscript {
ext.kotlin_version = '1.1.2-2'
repositories {
mavenCentral()
}
dependencies {
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
// apply the kotlin-gradle plugin
apply plugin: "kotlin"
apply plugin: 'application'
mainClassName = "hello.main"
// add kotlin-stdlib dependencies.
repositories {
mavenCentral()
}
dependencies {
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
}
Hello.kt:
package hello
fun main(args: Array<String>) {
println("Hello World!")
}
Then I run the gradle build and got the build\classes\main\hello\HelloKt.class
my question is: Why the file generated is .class not .jar and how to get the .jar file and how to run it, I tried running the generated file using kotlin -classpath HelloKt.class main but got an error error: could not find or load main class hello.main

The classes are the direct output of the Kotlin compiler, and they should be packaged into a JAR by Gradle afterwards. To build a JAR, you can run the jar task, just as you would in a Java project:
gradle jar
This task is usually run during gradle build as well, due to the task dependencies.
This will pack the Kotlin classes into a JAR archive (together with other JVM classes, if you have a multi-language project), normally located at build/libs/yourProjectName.jar.
As to running the JAR, see this Q&A for a detailed explanation: (link)

Thanks for #hotkey answer, it helped me going the correct way.
First of all there is a mistake in the main class declaration, as it should follow the new methodology, that is in the below format:
mainClassName = '[your_namespace].[your_arctifact]Kt'
namespace = package name
arctifact = file name
so, considering the names given in the example above where filename is: Hello.kt, and the namespace is hello, then:
mainClassName = `[hello].[Hello]Kt`
using the previous method, that contains:
apply plugin: 'application'
mainClassName = 'hello.HelloKt'
the generated .jar file is not including the kotlin runtime, so the only way to execute it, is by:
d:/App/build/libs/kotlin -cp App.jar hello.HelloKt
but in order to generate a self contained jar that can be self-executed, and contains the kotlin runtime then the build.gradle should be written as:
// set up the kotlin-gradle plugin
buildscript {
ext.kotlin_version = '1.1.2-2'
repositories {
mavenCentral()
}
dependencies {
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
// apply the kotlin-gradle plugin
apply plugin: "kotlin"
// add kotlin-stdlib dependencies.
repositories {
mavenCentral()
}
dependencies {
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
}
jar {
manifest {
//Define mainClassName as: '[your_namespace].[your_arctifact]Kt'
attributes 'Main-Class': 'hello.HelloKt'
}
// NEW LINE HERE !!!
from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
}
followed by gradle build, the [your_working_folder].jar file will be generated at the build/libs folder, assuming the working folder name is app, then file app.jar will be generated.
To run this file, one of the following 2 commands can be used:
D:\App\build\libs\java -jar App.jar
OR
D:\App\build\libs\kotlin App.jar hello.HelloKt

Add to subproject to gradle jar

How can I add a subproject referenced using project(':api') to the jar gradle builds?
This is the build.gradle of my main project. The subproject is includes as git submodule and has a similar buildscript.
apply plugin: 'java'
sourceCompatibility = 1.5
version = '1.0'
jar {
manifest {
attributes('Main-Class': '..........')
}
}
repositories {
mavenCentral()
}
dependencies {
compile files('libs/jfxrt.jar')
compile project(':api')
testCompile group: 'junit', name: 'junit', version: '4.11'
}

I figured it out on my own.
Include the source of a subproject in the main jar:
sourceSets {
main {
java {
srcDir project(':api').file('src/main/java')
}
}
}
Including the classes of a jar in the main jar:
jar {
from zipTree('libs/abc.jar')
}

Try to add classpath to your manifest file. You need to have directory (example below uses "lib") to keep jar files on which your project depends.
Try modifying your "jar" block in gradle build to something like this. I have some addition properties just for demonstration. But the important one is Class-Path
jar {
manifest.attributes(
'Class-Path': lib/api.jar
'Built-By': System.getProperty('user.name'),
'Built-JDK': System.getProperty('java.version'),
'Built-OS': System.getProperty('os.name'),
'Built-DATE': buildDate,
)
}
I hope it helps to fix your issue.

In the simplest case, a fat Jar can be created as follows:
main/build.gradle:
jar {
from configurations.runtime
}
There are other, more robust solutions, such as the gradle-one-jar plugin for "main" method style applications.