How to synchronize web application and android application in java?

Question

Mobile development

Hello.
I am planning to create two applications in java.
Web application and android application.
The web application parses the data, performs calculations, and adds it to the database. And the android application makes a request for this data, also makes a request for editing and adding new data. The amount of data is average, up to 5000 records (text, numbers, pictures, links). It is necessary that these two applications are synchronized with each other. But I don't know how to implement it. As I understand it, you need to use a web server, and so that both applications make requests to it. Do you need a database in this case? Which database and web server to choose? How to establish a connection between a web server and a database?

Answer 1

Do you need a database in this case?

Need

How to establish a connection between a web server and a database?

Write a backend with REST api , for Android application + Postgresql DBMS (or any other DBMS of your choice)
Use the same database from a web application.

Answer 2

I imagine the project architecture as follows:
Service-process, which

parses data, performs calculations and adds to the database.

A web service that serves HTTP requests from a mobile application. When parsing requests come in, it adds a task to the queue, and the parser service processes it. If something is fast, then in place and updates the data.