How to create an executable Jar file using maven

In this blog post, we will learn how to create a simple quick start project which can be build into a jar file, upon it’s’ execution will call a java class with main method.

Create maven quick start project

 mvn archetype:generate -DgroupId=com.test -DartifactId=test -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

JAR Plugin

The Maven’s jar plugin will create jar file and we need to define the main class that will get executed when we run the jar file.

        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
          <configuration>
            <archive>
              <manifest>
                <addClasspath>true</addClasspath>
                <mainClass>com.test.App</mainClass>
              </manifest>
            </archive>
          </configuration>
        </plugin>

Create a main class with name APP and the below sample will create a random hash code string and print it. So when we execute the jar file, this class will be called, and that is what we have defined under the plugin section in the pom above, under the tag <mainClass>com.test.App</mainClass>

public class App {
   public static void main(String args[]){
     String str= generateSHA512hash("lav");
     System.out.println("Random String is: "+str);
   }
}

Maven Package

Maven package will create the executable jar file

The jar file should be ready under the target directory

mvn package

Execute the jar file using the command below,

java -jar test-1.0-SNAPSHOT.jar

Result

ee26b0dd4af7e749aa1a8ee3c10ae9923f618980772e473f8819a5d4940e0db27ac185f8a0e1d5f84f88bc887fd67b143732c304cc5fa9ad8e6f57f50028a8ff