Maven-Shade plugin usage

pom.xml

<build>
        <plugins>
            <plugin>
                <groupid>org.apache.maven.plugins</groupId>
                <artifactid>maven-shade-plugin</artifactId>
                <version>1.4</version>
                <executions>
                  <execution>
                    <phase>package</phase>
                    <goals>
                      <goal>shade</goal>
                    </goals>
                    <configuration>
                      <transformers>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                          <mainclass>Main Class of the jar file</mainClass>
                        </transformer>
                      </transformers>
                    </configuration>
                  </execution>
                </executions>
           </plugin>
        </plugins>
  </build>