gradle - how do I build a jar with a lib dir with other jars in it?

simple:

task copyToLib( type: Copy ) {
    into "$buildDir/libs/lib"
    from configurations.runtime
}

jar { dependsOn copyToLib }

run it:

$ gradle jar
...
$ tree build/libs

build/libs
├── your-project-0.0.1.BUILD-SNAPSHOT.jar
└── lib
    ├── akka-actor-2.0.jar
    ├── akka-camel-2.0.jar
    ├── ... ... ...
    ├── spring-expression-3.1.0.RELEASE.jar
    └── zmq-2.1.9.jar

1 directory, 46 files

I also needed to do something similar and wasn't quite able to get what Guus and stigkj suggested working, but got close enough with their help to get this working (Guus' example blew up on the dependencies { compile { extendsFrom myLibs }} closure for me.

apply plugin: 'groovy'

repositories {
    mavenCentral()
}

configurations {
    // custom config of files we want to include in our fat jar that we send to hadoop
    includeInJar
}

dependencies {
    includeInJar 'org.codehaus.groovy:groovy:1.8.6'

    configurations.compile.extendsFrom(configurations.includeInJar)
}

jar {
    into('lib') {
        println "includeInJar: " + configurations.includeInJar.collect { File file -> file }
        from configurations.includeInJar
    }

}

Then running gradle jar and examining the created jar gives me this output, showing that I get the jar file to have groovy as well as all jars that it's dependent on inside the "fat jar":

%  gradle jar                                                                                                                         
includeInJar: [/Users/tnaleid/.gradle/caches/artifacts-8/filestore/org.codehaus.groovy/groovy/1.8.6/jar/553ca93e0407c94c89b058c482a404427ac7fc72/groovy-1.8.6.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/antlr/antlr/2.7.7/jar/83cd2cd674a217ade95a4bb83a8a14f351f48bd0/antlr-2.7.7.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/asm/asm/3.2/jar/9bc1511dec6adf302991ced13303e4140fdf9ab7/asm-3.2.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/asm/asm-tree/3.2/jar/cd792e29c79d170c5d0bdd05adf5807cf6875c90/asm-tree-3.2.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/asm/asm-commons/3.2/jar/e7a19b8c60589499e35f5d2068d09013030b8891/asm-commons-3.2.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/asm/asm-util/3.2/jar/37ebfdad34d5f1f45109981465f311bbfbe82dcf/asm-util-3.2.jar, /Users/tnaleid/.gradle/caches/artifacts-8/filestore/asm/asm-analysis/3.2/jar/c624956db93975b7197699dcd7de6145ca7cf2c8/asm-analysis-3.2.jar]
:compileJava UP-TO-DATE
:compileGroovy UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:jar

BUILD SUCCESSFUL

Total time: 3.387 secs

%  jar tvf build/libs/gradletest.jar                                                                                                  
     0 Mon Mar 12 11:40:00 CDT 2012 META-INF/
    25 Mon Mar 12 11:40:00 CDT 2012 META-INF/MANIFEST.MF
     0 Mon Mar 12 11:40:00 CDT 2012 lib/
5546084 Mon Mar 05 13:13:32 CST 2012 lib/groovy-1.8.6.jar
445288 Mon Mar 05 13:13:38 CST 2012 lib/antlr-2.7.7.jar
 43398 Mon Mar 05 13:13:40 CST 2012 lib/asm-3.2.jar
 21878 Mon Mar 05 13:13:40 CST 2012 lib/asm-tree-3.2.jar
 33094 Mon Mar 05 13:13:40 CST 2012 lib/asm-commons-3.2.jar
 36551 Mon Mar 05 13:13:40 CST 2012 lib/asm-util-3.2.jar
 17985 Mon Mar 05 13:13:40 CST 2012 lib/asm-analysis-3.2.jar

I had the same problem. I solved it like this:

Copy the files into the lib folder with copyToLib and reference the dependency with the Class-Path

ext.mainClass = 'test.main'

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.google.code.gson:gson:2.8.2'
    //....
}

jar {
    from "$buildDir/libs/lib"
    manifest {
        attributes 'Main-Class': 'test.main',
        'Class-Path': configurations.compile.collect { 'lib/'+it.getName() }.join(' ')
    }
}

task copyToLib(type: Copy) {
    into "$buildDir/libs/lib"
    from configurations.compile
}

build.dependsOn(copyToLib)

Here's how I managed to achieve this build setting using Gradle. This will build your app into a Jar, copy the library jars generated into the libs directory under build/libs and also configure classpath to include the jars in the created build/libs/libs directory.

 plugins {
    id 'application'
 }

 group 'org.pkg'
 version '1.0-SNAPSHOT'

 ext.mainClass = 'org.pkg.MainClass'

 repositories {
    mavenCentral()
    mavenLocal()
 }

 dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile group: 'junit', name: 'junit', version: '4.12'

    implementation group: 'com.mchange', name: 'c3p0', version: '0.9.5.5'
 }
 
 task copyToLib(type: Copy) {
    into "$buildDir/libs/libs"
    // configurations.runtimeClasspath includes maven jars
    from configurations.runtimeClasspath 
 }

 def archiveVersion = "1.0.0"

 task uberJar(type: Jar) {
    archiveClassifier = 'uber'

    from sourceSets.main.output
    // include the copy task
    dependsOn(copyToLib)

    // use onfigurations.runtimeClasspath to collect all the jars
    manifest {
      attributes(
            'Class-Path': configurations.runtimeClasspath.collect { 'libs/' + it.getName() }.join(' '),
            'Main-Class': 'org.pkg.MainClass',
            "Implementation-Title": "Gradle",
            "Implementation-Version": archiveVersion
      )
    }
 }