How do I connect to PostgreSQL using JDBC?

To connect to a PostgreSQL database using JDBC, you’ll need the PostgreSQL JDBC driver and a properly formatted connection URL.

1. Add the Dependency

Add the following dependency to your pom.xml file:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.7.4</version>
</dependency>

2. Establish the Connection

In modern JDBC (4.0+), you no longer need to manually call Class.forName(). The DriverManager will automatically find the driver on your classpath.

Here is a standard example using a try-with-resources block to ensure the connection is closed automatically:

package org.kodejava.jdbc;

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

public class PostgresConnectionExample {
    public static void main(String[] args) {
        // URL format: jdbc:postgresql://<host>:<port>/<database>
        String url = "jdbc:postgresql://localhost:5432/your_database";
        String user = "your_username";
        String password = "your_password";

        try (Connection connection = DriverManager.getConnection(url, user, password)) {
            if (connection != null) {
                System.out.println("Connected to the PostgreSQL server successfully!");
            }
        } catch (SQLException e) {
            System.err.println("Connection failure: " + e.getMessage());
        }
    }
}

Key Details:

• JDBC URL: The prefix is always jdbc:postgresql://. The default port for PostgreSQL is 5432.
• Driver Class: If you are working with older code that requires it, the driver class name is org.postgresql.Driver.