How to Test a JDBC Driver

The JDBC driver is used in applications to call procedures and query tables in mySQL. When programming a database connection, it's important to test the driver connection by wrapping it in a "try-catch" block of code. If the connection succeeds, the code continues to execute. However, if the connection fails, the "try-catch" block will report an error to the console. This is accomplished in Java using only a few lines of code. This code can be used individually to test the driver installation, or it can be inserted into an application class.

Instructions

1. Import the Java libraries needed to handle the JDBC driver calls. Enter the following code at the top of the workspace file:
   import java.sql.Connection;
   import java.sql.DriverManager;
   import java.sql.SQLException;

2. Create the try-catch block. The following code is an example of a try-catch block shell. The code that tests the JDBC driver is inserted into this block.
   try {
   } catch(Exception exc) {
   }

3. Instantiate the JDBC driver class and try to connect to the mySQL server. If this fails, the code flow jumps to the "catch" block. The following code instantiates the class and creates a connection.
   try {
   Class.forName("com.mysql.jdbc.Driver").newInstance();
   myConnection = DriverManager.getConnection("jdbc:mysql:///myTestSQLDatabase", "myUsername", "myPassword");
   }
   catch (Exception exc) {
   }

4. Test if the connection opens. The following code detects if the connection opens after initialization of the JDBC driver. The reason this is not in the error section is that the JDBC driver may still be installed properly, but a connection was refused by the SQL server.
   try {
   Class.forName("com.mysql.jdbc.Driver").newInstance();
   myConnection = DriverManager.getConnection("jdbc:mysql:///myTestSQLDatabase", "myUsername", "myPassword");
   if(!myConnection.isClosed()) {
   System.out.println("The SQL connection was successful.");
   }
   }
   catch (Exception exc) {
   }

5. Create the error handling code. If the JDBC driver is installed improperly or it does not exist, an error is flagged and code flow is sent to the "catch" statement. The following code prints an error message to the console:
   try {
   Class.forName("com.mysql.jdbc.Driver").newInstance();
   myConnection = DriverManager.getConnection("jdbc:mysql:///myTestSQLDatabase", "myUsername", "myPassword");
   if(!myConnection.isClosed()) {
   System.out.println("The SQL connection was successful.");
   }
   }
   catch (Exception exc) {
   System.out.println("JDBC Driver error:" + exc.getMessage() );
   }

References

• stardeveloper.com