DriverManager - Loading JDBC Driver

This section describes how to load a JDBC driver and register it with DriverManager.

If you want to use DriverManager class to create a connection to a database server, you need to load a JDBC driver that knows how to create a connection to that database server. The loaded JDBC driver class will be automatically registered to DriverManager.

There are two ways to load a JDBC driver:

I wrote the following program to test both ways of loading JDBC drivers. To test this program, you need to download Microsoft JDBC Driver as described in another tutorial in this book.

/* LoadJdbcDriver.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.sql.*;
import java.util.*;
public class LoadJdbcDriver {
  public static void main(String [] args) {
    Connection con = null;
    try {
      System.out.println("Before loading SQLServerDriver:");
      listDrivers();

// Load Microsoft JDBC Driver
      Class.forName(
        "com.microsoft.sqlserver.jdbc.SQLServerDriver");

      System.out.println("After loading SQLServerDriver:");
      listDrivers();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
    }
  }
  private static void listDrivers() {
    Enumeration driverList = DriverManager.getDrivers();
    while (driverList.hasMoreElements()) {
      Driver driverClass = (Driver) driverList.nextElement();
      System.out.println("   "+driverClass.getClass().getName());
    }
  }
}

Test 1 - Load Microsoft JDBC Driver with Class.forName() with newer versions of JDK by follow the commands below:

herong> java -version

java version "17.0.1" 2021-10-19 LTS

herong> java -cp mssql-jdbc.jar LoadJdbcDriver.java

Before loading SQLServerDriver:
   com.microsoft.sqlserver.jdbc.SQLServerDriver
After loading SQLServerDriver:
   com.microsoft.sqlserver.jdbc.SQLServerDriver

Test 2 - Load Microsoft JDBC Driver with jdbc.drivers property with JDK by follow the commands below. The backslash at the end of line indicates that the command continues on the next line.

herong> java -cp mssql-jdbc.jar \
   -Djdbc.drivers="com.microsoft.sqlserver.jdbc.SQLServerDriver" \
   LoadJdbcDriver.java

Before loading SQLServerDriver:
   com.microsoft.sqlserver.jdbc.SQLServerDriver
After loading SQLServerDriver:
   com.microsoft.sqlserver.jdbc.SQLServerDriver

What I learned from the outputs of the two tests:

If we compare the output of the same tests with JDK 1.6 as presented below, you will see that newer versions of JDK have changed on how JDBC drivers are loaded.

Test 3 - Load Microsoft JDBC Driver with Class.forName() with JDK 1.6 by follow the commands below:

herong> java -version
java version "1.6.0_02"
Java(TM) SE Runtime Environment (build 1.6.0_02-b06)
Java HotSpot(TM) Client VM (build 1.6.0_02-b06, mixed mode, sharing)

herong> javac LoadJdbcDriver.java

herong> java -cp sqljdbc.jar LoadJdbcDriver

Before loading SQLServerDriver:
   sun.jdbc.odbc.JdbcOdbcDriver
After loading SQLServerDriver:
   sun.jdbc.odbc.JdbcOdbcDriver
   com.microsoft.sqlserver.jdbc.SQLServerDriver

Test 4 - Load Microsoft JDBC Driver with jdbc.drivers property with JDK 1.6 by follow the commands below:

herong> java -cp sqljdbc.jar \
   -Djdbc.drivers="com.microsoft.sqlserver.jdbc.SQLServerDriver" \
   LoadJdbcDriver

Before loading SQLServerDriver:
   sun.jdbc.odbc.JdbcOdbcDriver
   com.microsoft.sqlserver.jdbc.SQLServerDriver
After loading SQLServerDriver:
   sun.jdbc.odbc.JdbcOdbcDriver
   com.microsoft.sqlserver.jdbc.SQLServerDriver

What I learned from the outputs of the two tests with JDK 1.6:

Table of Contents

 About This Book

JDBC (Java Database Connectivity) Introduction

 What Is JDBC?

 JDBC Version and History

 JDBC Driver Types

 Establishing Connections from JDBC to Databases

DriverManager - Loading JDBC Driver

 DriverManager - Connection URL

 JDK (Java SE) Installation

 Installing and Running Java DB - Derby

 Derby (Java DB) JDBC Driver

 Derby (Java DB) JDBC DataSource Objects

 Java DB (Derby) - DML Statements

 Java DB (Derby) - ResultSet Objects of Queries

 Java DB (Derby) - PreparedStatement

 Summary of JDBC Drivers and Database Servers

 Using Connection Pool with JDBC

 Archived Tutorials

 References

 Full Version in PDF/EPUB