no main manifest attribute in maven jar

Maven have a pretty awesome tutorial in their getting started guide here: http://maven.apache.org/guides/getting-started/index.html

The problem is that if you follow it letter for letter, then run:

java -jar target/<jarname.jar>

you receive a “no main manifest attribute” error.

Stackoverflow has a good answer for this problem, but it took a few readings before I understood what they were saying. Here’s a link to the stackoverflow question:

http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven

Open your pom.xml and add the section listed:

<build>
   <plugins>
      <plugin>
          <artifactId>maven-assembly-plugin</artifactId>
          <configuration>
          <archive>
               <manifest>
                    <mainClass>fully.qualified.MainClass</mainClass>
               </manifest>
          </archive>
     <descriptorRefs>
          <descriptorRef>jar-with-dependencies</descriptorRef>
      </descriptorRefs>
 </configuration>
</plugin>
</plugins>
</build>

This goes after the URL tag, but before the dependencies tag.

After this, run the following maven command:

mvn clean compile assembly:single

This will output a jar-with-dependencies.jar file in your target\ directory.