maven add main class for jar

  <build>
 <plugins>
  <plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-shade-plugin</artifactId>
   <version>2.1</version>
   <executions>
    <execution>
     <phase>package</phase>
     <goals>
      <goal>shade</goal>
     </goals>
     <configuration>
      <transformers>
       <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
        <mainClass>cl.clave.App</mainClass>
       </transformer>
      </transformers>
     </configuration>
    </execution>
   </executions>
  </plugin>
 </plugins>
</build>