To import an EJB JAR file into an EJB project using the Import wizard:
Imported .class files
You can also import an EJB JAR file that contains binary .class files only, with no no source code. The beans can be mapped, and deployment code can be generated, or new enterprise beans that depend on the contents of the JAR can be created.
A folder called xxx.imported_classes will contain only .class files. All other files (for example, source files and .properties files) are copied to the source folder of the EJB project during import. This strategy allows the EJB tools to reflect the shape of the binary Java™ classes, in order to map, assemble, and deploy the imported JAR file.
On an EJB JAR export, the contents of the xxx.imported_classes folder are merged into the resulting EJB JAR. That is, the exported JAR file will be a single archive which contains the merged contents of the Java output folder of the EJB project and the xxx.imported_classes folder.