You may use Eclipse to have a better understanding of what you are working on within your private server. Creating a project and importing client and source will give you the workspace and help you may find useful. Eclipse may suggest errors worth fixing within your files and give you some guidance. 

I think intellij is better but any ide will do.

IDE For Java EE Developers

i like intellij more tbh

 

Yea, JetBrains (creators of intellij) are pretty awesome. They make tools for other languages too.