Create an API connection from a Web app to Java App

I am looking for a skilled developer to update a web app already build with an API that will allow for data submission to an external java app already build. The purpose of this API is to process user-submitted data and receive a PDF file from the Java APP. The java app is already build as well, the developer just need to add the API libraries so it can receive information VIA api instead of user interphase.

Key Requirements:
- Ability to create a secure and efficient web app API for data submission
- Experience with Java programming language
- Knowledge of best practices for handling user data

Specific Functionalities:
- I have a detailed list of functionalities and desired results for the Java application. The developer will need to implement these functionalities according to the specifications provided.

Timeline:
- The project is urgent and needs to be completed within 1-2 weeks.

Ideal Skills and Experience:
- Strong proficiency in Java programming language
- Previous experience working with CodeIgniter web app APIs and data process
- Familiarity with best practices for data security and privacy

If you are confident in your Java programming skills and have experience with web app APIs, please reach out to discuss further details of the project.