My problem is that: I am using a serialized class in my project.( i.e. I created another project, I made up a serialized class in this this project And I compiled this project. Later I added this project to my actual/first project' s library folder for using this seralized class.) After I disposed my actual project. I builded it for creating a jar file. But any jar file is not falling out (I am using NetBeans) Could you help me please to solve this problem?