In this tutorial, we will show you how to use Gradle build tool to create a single Jar file with dependencies.

Tools used :

  1. Gradle 2.0
  2. JDK 1.7
  3. Logback 1.1.2

1. Project Directory

Create following project folder structure :

gradle-hello-folder

By default, Gradle is using the standard Maven project structure.

  1. ${Project}/src/main/java/
  2. ${Project}/src/main/resources/
  3. ${Project}/src/test/java/

2. Java Files

A single Java file to print out the current date time, and logs the message with logback.

DateUtils.java

package com.mkyong;

import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DateUtils{
	
	private static final Logger logger = LoggerFactory.getLogger(DateUtils.class);
	
	public static void main(String[] args) {
		
		logger.debug("[MAIN] Current Date : {}", getCurrentDate());
		System.out.println(getCurrentDate());
	}
	
	private static Date getCurrentDate(){
		return new Date();
	}
	
}
logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

	<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
	  <layout class="ch.qos.logback.classic.PatternLayout">

		<Pattern>
			%-5level %logger{36} - %msg%n
		</Pattern>

	  </layout>
	</appender>

	<root level="debug">
	  <appender-ref ref="STDOUT" />
	</root>

</configuration>

3. build.gradle

A build.gradle sample to create a Jar file along with its logback dependencies.

build.gradle

apply plugin: 'java'
apply plugin: 'eclipse'

version = '1.0'
sourceCompatibility = 1.7
targetCompatibility = 1.7

//create a single Jar with all dependencies
task fatJar(type: Jar) {
	manifest {
        attributes 'Implementation-Title': 'Gradle Jar File Example',  
        	'Implementation-Version': version,
        	'Main-Class': 'com.mkyong.DateUtils'
    }
    baseName = project.name + '-all'
    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
    with jar
}

//Get dependencies from Maven central repository
repositories {
    mavenCentral()
}

//Project dependencies
dependencies {
	compile 'ch.qos.logback:logback-classic:1.1.2'
}

4. Create a Jar File

Clean the project.


$ gradle clean 

Run the Gradle fatJar task.


$ gradle fatJar 

:compileJava
:processResources
:classes
:fatJar

BUILD SUCCESSFUL

Total time: 6.4 secs

The Jar is created under the $project/build/libs/ folder.

gradle-build-folder

5. Run It

Run it – java -jar hello-all-1.0.jar.


$Project\build\libs> java -jar hello-all-1.0.jar
16:22:13,249 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy]
16:22:13,249 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml]
//...

DEBUG com.mkyong.DateUtils - [MAIN] Current Date : Wed Aug 27 16:22:13 SGT 2014
Wed Aug 27 16:22:13 SGT 2014

Done.

Download Source Code

Download It – gradle-create-single-jar.zip (1.4 KB)

References

  1. Gradle : Jar Task
  2. Wikipedia : Gradle