How to implement a messaging service in react-native with a java backend?

I am creating an app using React-Native for the front-end, Java for the back-end and PostgreSQL for the database.

One feature of this app is to allow users to add each other as friends and instant message them - just like other social networks. At the moment, security is not a priority but I don't want to create something that I will have to completely redo when I do have to make it secure!

The goal here is to give each user the ability to send/receive messages to/from their friends. They also need to be able to view the message history with each contact.

I just need some advice on the following points to get me going as I haven't gotten very far on my own:

• How should I send messages from the front-end, to the Java server and then to the receiver? This will involve the app having to listen for new messages so would the Socket.IO library be the way to go for this?
• How I should store the messages in the database? E.g. have a table for messages with user_ids to be used for retrieval?

I should point out that I am very new to React-Native, databases and networking so I am finding this very challenging!

I will massively appreciate any help and any examples would be fantastic!

You should use WebSocket on the server. Spring supports it

Here's a tutorial I wrote about sending messages from PostgreSQL to the browser using WebSocket, which isn't exactly what you're going to do, but can hopefully get you started:

http://blog.databasepatterns.com/2014/04/postgresql-nofify-websocket-spring-mvc.html