我将对提议的解决方案和帮助我的解决方案进行总结！

I'm going to make a summary of the proposed solutions and the one that helped me!

一个阅读此错误报告：
NetBeans 6.8为a创建jar的方式中的错误Java Library Project。

After reading this bug report: bug in the way NetBeans 6.8 creates the jar for a Java Library Project.

1. 在项目根目录中创建manifest.mf文件

1. Create a manifest.mf file in my project root

编辑manifest.mf。我看起来像这样：

Edit manifest.mf. Mine looked something like this:

Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.1
Created-By: 16.3-b01 (Sun Microsystems Inc.)
Main-Class: com.example.MainClass
Class-Path: lib/lib1.jar lib/lib2.jar