I just had the same problem in NetBeans 7.2.1 with a Maven Java Application project. Modify the pom.xml file to include the maven assembly plugin with one tweak to myrho’s answer (needs to reference the predefined descriptor “jar-with-dependencies”):
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>your.app.MainClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
An alternate method is to build a Java Application project in NetBeans that doesn’t use Maven. Select File -> Project Properties -> Build -> Packaging and check the “Copy Dependent Libraries” checkbox.