# Defining the JAR file's manifest

You can either define the important parts of the JAR file manifest directly in the wizard or choose to use a manifest file that already exists in your workbench.

## Creating a new manifest

1. Follow the procedure for creating a JAR file, but click Next in the last step to go to the JAR Packaging Options page.
2. Set any advanced options that you want to set, and then click Next again to go to the JAR Manifest Specification page.
3. If it is not already selected, click the Generate the manifest file button.
4. You can now choose to save the manifest in the workbench. This will save the manifest for later use. Click Save the manifest in the workspace, then click Browse next to the Manifest file field to specify a path and file name for the manifest.
5. If you decided to save the manifest file in the previous step and you chose to save the JAR description on the previous wizard page, then you can choose to reuse it in the JAR description (by selecting the Reuse and save the manifest in the workspace checkbox). This means that the saved file will be used when the JAR file is recreated from the JAR description.This option is useful if you want to modify or replace the manifest file before recreating the JAR file from the description.
6. You can choose to seal the JAR and optionally exclude some packages from being sealed or specify a list with sealed packages. By default, nothing is sealed.
7. Click the Browse button next to the Main class field to specify the entry point for your applications.
   Note: If your class is not in the list, then you forgot to select it at the beginning.
8. Click Finish. This will create the JAR, and optionally a JAR description and a manifest file.

## Using an existing manifest

You can use an existing manifest file that already exists in your workbench.

1. Follow the procedure for creating a JAR file, but click Next in the last step to go to the JAR Packaging Options page.
2. Set any advanced options that you want to set, and the click Next again to go to the JAR Manifest Specification page.
3. Click the Use existing manifest from workspace radio button.
4. Click the Browse button to choose a manifest file from the workbench.
5. Click Finish. This will create the JAR and optionally a JAR description.

Java development tools (JDT)

Creating a new JAR file
Setting advanced options

JAR file exporter