JDBC — java.lang.NoClassDefFoundError: Could not initialize class com.mysql.jdbc.Connection

Question

I have the following code that\'s trying to establish a connection to a remote database. It\'s throwing an exception, and I can\'t figure out why.

    impor         


        

Answer 1

Try this:

try
{   // Load driver class
    Class.forName("com.mysql.jdbc.Driver");
}
catch (java.lang.ClassNotFoundException e) {
    System.err.println("ClassNotFoundException: " +e);
}

Instead of:

 try {
    // Exception thrown in next line.
        Class.forName(driver).newInstance();
        conn = DriverManager.getConnection(url, userName, password);
    } catch (Exception e) {
        return null;
    }

Answer 2

This is almost certainly because you are missing the jdbc driver jar for MySql. You can find it Here. Unzip it and add the jar to your classpath.

Update: You can not use MySQL with GAE because sockets are not allowed. This will never work for you. They have alternative persistence mechanisms besides MySQL. See: Can I use a MySQL database with an App Engine application