GWT with JDO problem

Question

I just start playing with GWT I\'m having a really hard time to make GWT + JAVA + JDO + Google AppEngine working with DataStore. I was trying to follow different tutorial bu

Answer 1

Could it be that you forgot to create the implementation for the RPCCallsService? I can't see it from the list of files that you have.

You should have a file called RPCCallsServiceImpl.java in RPCCalls/src/com/example/rpccalls/server/, it is the implementation file for the interface RPCCallsService.java.

It will look something like this:

import javax.jdo.JDOHelper;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.example.rpccalls.client.RPCCallsService;

public class RPCCallsServiceImpl extends RemoteServiceServlet implements RPCCallsService {

  // Factory to get persistence manager object later
  private static final PersistenceManagerFactory PMF = JDOHelper.getPersistenceManagerFactory("transactional-optional");

  public String saveName(Person p) {
    // Data Store need persistence manager object for writing to it 
    PersistenceManager pm = PMF.getPersistenceManager();

    // Recommended way to save an object to the data store
    try {
      pm.makePersistent(p);
    } finally {
      pm.close();
    }

    // You want it to return string
    return p.getName();
  }

}

Hopefully this help you to solve the problem. Cheers :)