Build A P2P Client/Server Java Program

Local Student IM application(Running on the same computer) Need a chat program in java that lets users sign up and stores their username and password(Into simple text file is fine, does not need to be secured). Then the user can access the server to chat with other users on the server privately. The users should be able to share files at well. The message should be encrypted from end to end but file transfer does not need to be encrypted. The user should be able to send emojis as well. This can be a drop down menu and the user can select what he wants to send. Its should be a pretty simple program. 1. Run server 2. User registers and then should be able to login after registering 3. User will see who is online and choose who he wants to talk with 4. User can send picture files, emojis and messages(message will be encrypted with simple encryption) 5. If user presses EXIT he will exit the chat and will be allowed to talk with another user 6. Needs to have a simple GUI