AbstractMethodError calling remote method

Question

Java student and rank RMI newbie here; please go easy on me. My subinterface, remote class, and client app all compile fine, but when I run the client app I get an error:
Exception in thread "main" java.lang.AbstractMethodError: DatabaseUpdater_Stub.i
nitCourseList()Lcom/sun/rowset/CachedRowSetImpl;
        at EnrollPanel.<init>(Enroll3.java:99)
        at Enroll3.main(Enroll3.java:25)Here is my subinterface:
import com.sun.rowset.CachedRowSetImpl;
import java.rmi.*;
import java.sql.*;
import javax.sql.*;
public interface DbUpdaterInterface extends Remote
     public abstract CachedRowSetImpl initCourseList() throws RemoteException, SQLException;
     public abstract CachedRowSetImpl initStudentList() throws RemoteException, SQLException;
     public abstract CachedRowSetImpl initEnrollmentList() throws RemoteException, SQLException;
     public abstract void addNewCourseInDb() throws RemoteException;
     public abstract void addStudentToCourseInDb() throws RemoteException;
     public abstract void addNewStudentInDb() throws RemoteException;
     public abstract void enrollStudentInCourseInDb() throws RemoteException;
}and the remote class that implements the interface:
import com.sun.rowset.CachedRowSetImpl;
import java.net.*;
import java.rmi.*;
import java.rmi.server.*;
import java.sql.*;
import javax.sql.*;
public class DatabaseUpdater extends UnicastRemoteObject implements DbUpdaterInterface
     Connection dbConnection;
     public DatabaseUpdater(Connection dbConnection) throws RemoteException
          this.dbConnection = dbConnection;
     public CachedRowSetImpl initCourseList() throws RemoteException, SQLException
          CachedRowSetImpl rset = new CachedRowSetImpl();
          Statement courseStatement = dbConnection.createStatement();
          String courseQuery = "SELECT CourseID, MaxEnrollment, CurrentEnrollment FROM Courses";
          ResultSet courseResults = courseStatement.executeQuery(courseQuery);
          rset.populate(courseResults);
          courseStatement.close();
          return rset;
// ... some more methods ...
     public static void main(String []args)
          try
               Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
               Connection dbConnection = DriverManager.getConnection("jdbc:odbc:DRIVER={Microsoft Access Driver (*.mdb)};DBQ=project3.mdb");
               DatabaseUpdater x = new DatabaseUpdater(dbConnection);   // a remote object
               Naming.rebind("DatabaseUpdater", x);   // the remote object is named as "DatabaseUpdater"
               System.out.println("Database updater is running....");
          catch (Exception e)
               System.err.println(e);
}In my client app, here is the problem code, with the last line being the one that throws the error:
               // invoke remote DatabaseUpdater object
               DbUpdaterInterface dbUpdater = (DbUpdaterInterface) Naming.lookup("DatabaseUpdater");
               // call remote object to get result set of all courses, students, enrollments
               CachedRowSetImpl courseResults = dbUpdater.initCourseList();Any ideas? AbstractMethodError refers to trying to call an abstract method, but I have my subinterface's initCourseList() method implemented in my remote class just fine. I'd greatly appreciate some help!

Answer 1

Oops, my mistake. I had made changes since last running rmic on my remote class. Nothing to see here, move along!