Convert JAR to JAD

Jar to jad file conversion

A JAR file is a Java archive that contains compiled classes, resources, and metadata. A JAD file is a Java Application Descriptor used mainly on older Java ME devices to describe an application and point to its JAR file.

You cannot truly convert a JAR into a JAD in the sense of recovering a descriptor from the archive alone. A JAD file is a separate plain-text descriptor, not a compiled output of the JAR.

If you already have the JAR and need a JAD file, you can generate a JAD descriptor by extracting the required metadata from the JAR manifest or by creating the descriptor manually. Some Java ME development tools can generate it automatically during packaging, but support is limited because Java ME is largely obsolete.

Typical JAD entries include:

• MIDlet-Name
• MIDlet-Version
• MIDlet-Vendor
• MIDlet-1
• MicroEdition-Profile
• MicroEdition-Configuration
• MIDlet-Jar-URL
• MIDlet-Jar-Size

To create one manually, open a text editor and save a plain-text file with the .jad extension. Make sure the values match the contents of the JAR and the target device requirements.

Important: a JAD file alone does not run the application. It must reference a valid JAR file, and both files are typically used together on Java ME devices.

If your goal is to inspect or modify a JAR, use a JAR viewer or unpack the archive instead. If your goal is to deploy a Java ME app, generate the JAD from the build tool or manifest data rather than trying to convert the archive directly.