What methods of integrating a database with a Java application exist?

There are several common ways to integrate a database with a Java application:

1. JDBC (Java Database Connectivity) — a standard API for connecting to relational databases. It allows executing SQL queries directly.

Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM users");

2. ORM frameworks (e.g., Hibernate, JPA) — enable working with the database through Java objects, abstracting away SQL.

3. Spring Data — simplifies database operations by providing repositories and automatic CRUD operation implementations.

4. NoSQL drivers — for integration with NoSQL databases (MongoDB, Cassandra), there are specialized Java drivers.

The choice of method depends on the type of database, performance requirements, and development convenience.