Question

I am trying to unit test a thin data access layer that I’ve written. I was hoping I wouldn’t have to inject a stub of DriverManager into the class that makes the connection, and I don’t have a mock framework available. I have check my implementation against MockRunner’s MockDriver and it is very similar, but when I run the test I get a SQLException: “No suitable driver found for jdbc:mysql://localhost:3306.” Here is the stub code:

public class DriverStub implements Driver
{
    @Override
    public boolean acceptsURL(String URL) throws SQLException
    {
        return true;
    }
    @Override
    public Connection connect(String url, Properties info) throws SQLException
    {
        return new ConnectionStub();
    }
    @Override
    public int getMajorVersion()
    {
        return 1;
    }
    @Override
    public int getMinorVersion()
    {
        return 0;
    }
    @Override
    public DriverPropertyInfo[] getPropertyInfo(String url, Properties info)
    throws SQLException
    {
        return new DriverPropertyInfo[0];
    }
    @Override
    public boolean jdbcCompliant()
    {
        return true;
    }
}

A fragment of the calling code:

Connection connection = null;
try
{
    Class.forName(driver).newInstance();
}
...
try
{
    connection = Drivermanager.getConnection(...);
}
...

Answer 1

The Driver implementation should register an instance of the Driver through DriverManager.registerDriver in its static initialiser.

public class DriverStub implements Driver {
    static {
        java.sql.DriverManager.registerDriver(new DriverStub());
    }
    ...
}

It’s a complete and utter hack, but there you go. Personally, I’d suggest ignoring DriverManager and linking directly to the driver.