Problems importing derby drivers in glassfish - servlets

Question

Good day to everyone,
I'm having some problems making Glassfish 3.1.2 seeing some imported jars. Because this i my grad project i have constraints. I cannot use anything else than Glassfish, Netbeans and i cannot use Maven, Hibernate, Ear or whathever.
I'm working with the embedded Derby driver. (I can use another DB, but in my trials the problem remains).
I've written some plain java code to connect to the DB:
try{
Connection c = DriverManager.getConnection(URL, USER, PWD);
Statement st = c.createStatement();
st.executeUpdate("CREATE TABLE Users" +
" (ACCOUNT VARCHAR(20) PRIMARY KEY," +
" PWD VARCHAR(20) NOT NULL," +
" USERTYPE INTEGER NOT NULL)");
...
}
catch (SQLException x){
System.out.println(x);
}
It's ugly, it doesn't use connection pools, it works. I'll use them later.
Obviously i had to add derbyclient.jar to the libs.
The problem arises when i try to use this method inside a servlet:
protected void processRequest(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
try{
DriverManager.registerDriver(org.apache.derby.jdbc.ClientDriver);
Connection c = DriverManager.getConnection(dbUsr, pwd, url);
Statement st = c.createStatement();
ResultSet rs = st.executeQuery(query);
...
}catch (SQLException e){
ServletException e1 = new ServletException(e.getMessage());
throw e1;
}
I cannot compile the servlet because "Package org.apache.derby.jdbc does not exists".
I can provide some more informations (20+ hours of reading and unsuccesful trials):
The servlet and the java code are in the same project, so derbyclient.jar should be seen by both of them.
When i write org.apache.berby netbeans shows me the package navigator for auto-completion, so somewhere it knows that there is a jar.
I tried to put derbyclient.jar inside:
Glassfish/glassfish/domains/domain1/lib
Glassfish/glassfish/domains/domain1/lib/ext
Glassfish/glassfish/lib
Tried without driver registration, the java code works without it, but i get "javax.servlet.ServletException: No suitable driver found for app". I find it reasonable.
I am at my wits end. Does someone care to help?
EDIT:
Yesterday I got news from the teacher: she blames Netbeans IDE for losing track of the jars. It seems to be a known bug.
I was warmly encouraged to switch to a tomcat server. I'll surely try it, bu i'll keep working to get this problem solved. Any other good ideas?

Answer 1

"No suitable driver found" usually means that the JDBC URL you've supplied to connect has incorrect syntax. Or the driver isn't loaded at all.
You have to load driver using Class.forName before connecting to DB.
URL for Derby is:
Class.forName("org.apache.derby.jdbc.ClientDriver");
More details on Derby check out the documentation
Also check that you have derby.jar in your classpath. I would suggest to place derby.jar at physical location to /WEB-INF/lib directory of your project.Then IDE will take care for the rest.

Answer 2

You should (in general) not register a driver yourself with the DriverManager That is the responsibility of the Driver implementation. For JDBC 3.0 and earliers (Java 5 and before) you need to load the class to get it to register itself:
Class.forName("org.apache.derby.jdbc.ClientDriver")
When the class is loaded, the driver registers itself with the DriverManager.
For JDBC 4.0 compliant drivers (Java 6 and 7) you don't even need to do that as JDBC 4.x uses the ServiceLoader mechanism and each compliant driver will lists its Driver implementations in a META-INF/services/java.sql.Driver file in its jar-file.
So in general you should NOT call 'DriverManager.registerDriver(..)' yourself. If for some reason you do need the register the driver yourself in code (eg because the driver actually doesn't register itself with the DriverManager automatically), then make sure that the actual driver is also on your compilation path (build path), and not just in the lib folder of your application server (this seems to be your actual problem).
Also remember that you will need to register an instance of Driver, not a class. So you will need to instantiate it:
DriverManager.registerDriver(new org.apache.derby.jdbc.ClientDriver());