In eclipse, how does one package a Java program into a jar package?

1. Right-click your project and choose export> JAVA> JAR file.

2. After completing the first step, you will enter a window where you can see that your project has been matched in the left-side window. The window on the right is the files in your project, all selected. Keep the settings in the window as default. Click Browse to set the path to be exported and click Next,
All the settings in the next window are default, directly next.
Step 3

3. After Entering step 3, there will be a main class tag under the window, click browse on the right
Select the program entry in your project (that is, the class containing the main method)
Then click Finish.

4. Finally, find the exported. jar file in the previously set path and double-click it to run it.