Hello iam new to GWT framework. I want to persist my domain objects/entities to google application engine datastore using rpc. A simple implementation to test if i can make multiple rpc calls ( greetServer() , saveStudent() )
Student
import javax.jdo.annotations.Extension;
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import com.google.gwt.user.client.rpc.IsSerializable;
@PersistenceCapable
public class Student implements IsSerializable {
private static final long serialVersionUID = 1L;
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
@Extension(vendorName = "datanucleus", key = "gae.encoded-pk", value = "true")
private int studentId;
@Persistent private String firstName;
@Persistent private String lastName;
public Student(){}
public Student(String firstName, String lastName){
this.firstName = firstName;
this.lastName = lastName;
}
public void setStudentId(int studentId) {
this.studentId = studentId;
}
public int getStudentId() {
return studentId;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getLastName() {
return lastName;
}
}
GreetingService (default code generated by Eclipse IDE)
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;
@RemoteServiceRelativePath("greet")
public interface GreetingService extends RemoteService {
String greetServer(String name) throws IllegalArgumentException;
**String saveStudent(Student s) throws IllegalArgumentException;**
}
GreetingServiceAsync
import com.google.gwt.user.client.rpc.AsyncCallback;
public interface GreetingServiceAsync {
void greetServer(String input, AsyncCallback<String> callback)
throws IllegalArgumentException;
**void saveStudent(Student s, AsyncCallback<String> callback)
throws IllegalArgumentException;**
}
GreetingServiceImpl
import javax.jdo.PersistenceManager;
import com.d.client.GreetingService;
import com.d.client.Student;
import com.d.shared.FieldVerifier;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
@SuppressWarnings("serial")
public class GreetingServiceImpl extends RemoteServiceServlet implements
GreetingService {
public String greetServer(String input) throws IllegalArgumentException
...
String serverInfo = getServletContext().getServerInfo();
String userAgent = getThreadLocalRequest().getHeader("User-Agent");
...
}
@Override
public String saveStudent(Student s) throws IllegalArgumentException {
PersistenceManager pm = PMF.get().getPersistenceManager();
pm.makePersistent(s);
return "student save - ok";
}
}
PMF
import javax.jdo.JDOHelper;
import javax.jdo.PersistenceManagerFactory;
public final class PMF {
private static final PersistenceManagerFactory pmfInstance = JDOHelper
.getPersistenceManagerFactory("transactions-optional");
private PMF() {
}
public static PersistenceManagerFactory get() {
return pmfInstance;
}
}
EntryPoint
...
private final GreetingServiceAsync greetingService = GWT
.create(GreetingService.class);
greetingService.greetServer("greet",
new AsyncCallback<String>() {
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
}
public void onSuccess(String result) {
//Show success message
}
});
greetingService.saveStudent(new Student("kostas","trichas"),
new AsyncCallback<String>() {
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
}
public void onSuccess(String result) {
//Show success message
}
});
...
Is the above implementation correct? I deployed this sample application to gae and it did not persisted the object student (you can browse the entities at gae datastore viewer)
check it please:
Change your int studentID to Long id to get it working