HibernateUtil.java

package com.phantom.db.util;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.springframework.stereotype.Component;

import java.sql.Connection;
import java.sql.DriverManager;

@Component
public class HibernateUtil {

    private static SessionFactory sessionFactory;
    private static Configuration configuration;

    public HibernateUtil() {
        if (sessionFactory == null) {
            sessionFactory = buildSessionFactory();
        }
    }

    private SessionFactory buildSessionFactory() {
        try {
            // Load configuration
            configuration = new Configuration().configure();

            // Test connection before building session factory
            testJDBCConnection();

            System.out.println("✅ JDBC connection test successful!");
            return configuration.buildSessionFactory();
        } catch (Throwable ex) {
            System.err.println("❌ Initial SessionFactory creation failed: " + ex.getMessage());
            ex.printStackTrace();
            throw new ExceptionInInitializerError(ex);
        }
    }

    private void testJDBCConnection() throws Exception {
        // Extract connection parameters from Hibernate config
        String driver = configuration.getProperty("hibernate.connection.driver_class");
        String url = configuration.getProperty("hibernate.connection.url");
        String username = configuration.getProperty("hibernate.connection.username");
        String password = configuration.getProperty("hibernate.connection.password");

        System.out.println("Testing JDBC connection with parameters:");
        System.out.println("Driver: " + driver);
        System.out.println("URL: " + url);
        System.out.println("Username: " + username);

        // Load driver class
        Class.forName(driver);

        try (Connection conn = DriverManager.getConnection(url, username, password)) {
            if (conn == null) {
                throw new Exception("DriverManager returned null connection");
            }

            System.out.println("Connection valid: " + conn.isValid(2));
        } catch (Exception e) {
            throw new Exception("JDBC connection test failed: " + e.getMessage(), e);
        }
    }

    public SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public Session getOpenSession() {
        return sessionFactory.openSession();
    }

    public void shutdown() {
        if (sessionFactory != null) {
            sessionFactory.close();
            System.out.println("Session factory closed");
        }
    }
}

/**
Output:
Testing JDBC connection with parameters:
Driver: com.mysql.cj.jdbc.Driver
URL: jdbc:mysql://localhost:3306/company_test?allowPublicKeyRetrieval=true
Username: root
Connection valid: true
? JDBC connection test successful!
com.phantom.configuration.PhantomStaticConfiguration@7e06eefb
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
Initial SessionFactory creation failed.org.hibernate.exception.GenericJDBCException: Unable to open JDBC Connection for DDL execution

Followed by
"Beans not being able to be created" errors.
*/