Errors from server to client

[beda meda]

Hi!
I'm not sure if this question belongs here, but I'll give it try. Here is my RMI application:

public class ServerStarter {
  private static Properties setProperties(String arg) {
    try {
      //some code
    }
    catch(IOException e) {
      //TODO
      e.printStackTrace();
    }
  }

  public static void main(String[] args) {
    try {
      //some code
    }
    catch(Exception e) {
      //TODO
      e.printStackTrace();
    }
  }
}

public class DBServer implements ServerInterface, DBServerInterface {

  public DBServer(Properties props) throws SQLException {
    //some code
  }

  public List<List<String>> receiveDataFromServer() throws RemoteException {
    try {
      //some code
    }
    catch(SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  public void writeDataToServer(List<List<String>> data) throws RemoteException {
    try {
      //some code
    }
    catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  public Connection createConnection() throws SQLException {
    try {
      //some code
    }
    catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  private void clearTable() throws SQLException {
    //some code
  }

  public void fillTable() {
    try {
      //some code
    }
    catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}

public class ClientStarter {

  public static void main(String[] args) {
    try {
      //some code
    }
    catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}

public class RMIClient implements ClientInterface {

  public RMIClient(ServerInterface stub)
      throws ClassNotFoundException, SQLException {
   //some code
  }

  public void callForData() {
    try {
      model.setData(stub.receiveDataFromServer());
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }

  public void sendData(List<List<String>> data) {
    try {
      stub.writeDataToServer(data);
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Now I need to get those exceptions from server to client. How should I do that?

[Edward Harned]

Passing data requires the data be serialized in both directions. The easiest way is to covert the messages to Strings and pass those to the client.

Next time only include the actual code that matters: http://sscce.org/

[beda meda]

Well, question is how:) Everything my server does is called from client. Now it should do something on its own, but it hasn't any reference to client. I was given hint that I can have some class MyErr on server side, which would wrap any exception that occurs there (e.g. MyErr(SQLException)), that would be wrapped in Remote exception RemoteException(MyErr(SQLException)),, that would be sent via RMI to Client and dealt with. But I"m not sure how to accomplish this.

[Nitesh Kant]

(I would recommend you to brush up your basics by some sun tutorials or some good book)

RemoteException is not meant to throw business exceptions. In most of the cases, RemoteException will be throws when there is a communication problem.

In your case you can define an exception class, may be, MyServerException and add in the throws clause of all your server methods. Whenever, an exception occurs on the server side you will throw this exception.

beda meda wrote: I was given hint that I can have some class MyErr on server side, which would wrap any exception that occurs there (e.g. MyErr(SQLException)), that would be wrapped in Remote exception RemoteException(MyErr(SQLException)),, that would be sent via RMI to Client and dealt with. But I"m not sure how to accomplish this.

Any Exception class will have a constructor that also takes a Throwable. You can wrap any exception into your desired type by using such a constructor.