E-MapReduce:Connect to a StarRocks instance by using JDBC

Step 1: Add the JDBC driver to your Maven project

Add the MySQL JDBC driver dependency to your pom.xml file:

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.27</version><!-- Modify the version based on your requirements. -->
</dependency>

Step 2: Connect and run a query

The following example connects to a StarRocks instance and runs a SQL query:

public class ConnStarrocks {

    static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
    // Format: jdbc:mysql://<FE node endpoint>:<fe_query_port>/<database>
    static final String DB_URL = "jdbc:mysql://localhost:9030/yourDatabaseName?useSSL=false&serverTimezone=UTC";

    // Replace with your actual username and password.
    static final String USER = "****";
    static final String PASSWORD = "1234*****";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try {
            // Load the JDBC driver.
            Class.forName(JDBC_DRIVER);

            // Establish the connection.
            System.out.println("Connecting.");
            conn = DriverManager.getConnection(DB_URL, USER, PASSWORD);

            // Run a query.
            System.out.println("Instantiating the Statement object...");
            stmt = conn.createStatement();
            String sql = "SELECT id, name, url FROM websites";
            ResultSet rs = stmt.executeQuery(sql);

            // Close resources.
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException se) {
            se.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (stmt != null) stmt.close();
            if (conn != null) conn.close();
        }
        System.out.println("Goodbye!");
    }
}

After the connection succeeds, the output is similar to:

Parameters

The following table describes the key parameters. Replace the placeholder values with your actual configuration.

Getting the FE node endpoint and query port

Both values are in the FE Details section of the Instance Details tab for your StarRocks instance.

• FE node endpoint: Use the internal endpoint if the StarRocks instance and your client are in the same virtual private cloud (VPC). Use the public endpoint if they are not — make sure the security group rules allow access from the required port. See Configure network security settings.

• Query port: The default is 9030.