As mentioned earlier, the manifest for a JAR is simple information about the classes bundled within a JAR. This manifest must be named manifest.mf and is required to be located in the meta-inf/ directory within the JAR.
When using the JBuilder Archive Builder, a default manifest file is generated. The following example of a manifest, Listing 9.1, is for a simple project.
Listing 9.1. The Required Portion of a Manifest File
The manifest version tells the user of the JAR what version of the manifest specification was utilized. Notice, that a manifest does not require any resources to be defined, although this makes the JAR not very useful. For a more practical example, Listing 9.2 is a subset of the JAR file ...