Java: export to an .jar file in eclipse

No need for external plugins. In the Export JAR dialog, make sure you select all the necessary resources you want to export. By default, there should be no problem exporting other resource files as well (pictures, configuration files, etc...), see screenshot below.

Go to file->export->JAR file, there you may select "Export generated class files and sources" and make sure that your project is selected, and all folder under there are also! Good luck!

FatJar can help you in this case.

In addition to the"Export as Jar" function which is included to Eclipse the Plug-In bundles all dependent JARs together into one executable jar.
The Plug-In adds the Entry "Build Fat Jar" to the Context-Menu of Java-projects

This is useful if your final exported jar includes other external jars.

If you have Ganymede, the Export Jar dialog is enough to export your resources from your project.

After Ganymede, you have: