Develop a Facebook like messenger in JSP

Main functions of the web application: 1. Send messages to a private user and group (multiple users). 2. Drag and drop approach / upload button to upload and send files. 3. Send images and show it to the users (click to zoom) 4. Emoji 5. Admin system to insert, modify and remove the records in the database There are some additional requirements in the following: 1. We suppose the messenger uses Ajax to send and receive messages. 2. This is a subsystem of our main web system. You need to provide good APIs for us to embed the messenger into our web system. 3. Settings must be configurable (eg. Max size of upload file, Emoji management) 4. Socket is required in this project 5. PostgreSQL will be used for our main system. You need to design the database schema for the messenger by yourself. 6. You are encouraged to use Spring framework for your development. 7. The messenger should support multilingual (allow us to add more language support in the future) For further information and changes, we will provide for you later.