CODEWITHSUNDEEP
javagwtcallback
Alessandro Mercurio
Alessandro Mercurio

Reputation: 508

GWT Async call always fail

I have some problems with my gwt project, i use eclipselink and hsqldb as database.

Here is my code: Project.java:

package com.example.client;
public class Project implements EntryPoint {

private final EmployeeServiceAsync eService = (EmployeeServiceAsync) GWT.create(EmployeeService.class);

[...] some GWT code


@Override
public void onModuleLoad() {

        eService.createemployee(new AsyncCallback<Void>() {
            @Override
            public void onFailure(Throwable caught) {
                Window.alert("Fail!");
            }
            @Override
            public void onSuccess(Void result) {
            //nothing
            }
        });

but it fail every time with this warning:

WARNING: No file found for: /project/employeeService

So how i can call this method properly?

EmployeeService.java

package com.example.client.service;
@RemoteServiceRelativePath("employeeService")
public interface EmployeeService extends RemoteService{

public void createemployee();
}

EmployeeServiceAsync.java

package com.example.client.service;
public interface EmployeeServiceAsync {

void createemployee(AsyncCallback<Void> callback);
}

EmployeeServiceImpl

package com.example.server.ServiceImpl;
public class EmployeeServiceImpl extends RemoteServiceServlet implements EmployeeService {

private static final long serialVersionUID = 1L;

public void createemployee() {

    javax.persistence.EntityManagerFactory emf = Persistence.createEntityManagerFactory("ronfPU");
    javax.persistence.EntityManager em = emf.createEntityManager();


    try {
 // Create new Employee
    em.getTransaction().begin();
    Employee e1 = new Employee();
    e1.setName("admin");
    e1.setSurname("admin");
    e1.setUsername("admin");
    e1.setPassword("admin");
    em.persist(a1);
    em.getTransaction().commit();
        } finally {
    em.close();
    }   
  }
}

Employee class is stored in com.example.shared.entity; I think that persistence.xml and project.gwt.xml are ok, but i'm not sure about web.xml code:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
          http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
     version="2.5" xmlns="http://java.sun.com/xml/ns/javaee">

<!-- Servlets -->
<servlet>
<servlet-name>employeeServiceImpl</servlet-name>
<servlet-class>
  com.example.server.ServiceImpl.EmployeeServiceImpl
</servlet-class>
</servlet>

<servlet-mapping>
  <servlet-name>employeeServiceImpl</servlet-name>
</servlet-mapping>

<!-- Default page to serve -->
<welcome-file-list>
<welcome-file>Project.html</welcome-file>
<url-pattern>/com.example.client.Project/employeeService</url-pattern>
</welcome-file-list>

</web-app>

First should be, if I understand correctly, derives from @RemoteServiceRelativePath("employeeService"); while <servlet-class> derives from the class stored in the server-side wich extends RemoteServiceServlet; <servlet-mapping> should be the same of <servlet-name>, and here, in <url-pattern>, i'm not sure about what i wrote.

How you suggest to run properly this code? Thank you in advance!

Upvotes: 0

Views: 523

Answers (1)

Thomas Broyer
Thomas Broyer

Reputation: 64541

When generating the code for your client-side service-async stub, it takes the value of the @RemoteServiceRelativePath annotation and prefixes it with the GWT.getModuleBaseURL() (this is explained in the javadoc for RemoteServiceRelativePath).

GWT.getModuleBaseURL() is the "folder" where your nocache.js file is located. In a standard setup, this depends directly on the name of your module (project.gwt.xml and the package you put it in) or a rename-to argument you have in it. According to the error message, it's http://…/project/ in your case (your nocache.js is at project/project.nocache.js).

You have to adjust the <url-pattern> in your web.xml file to match that URL, so it should be /project/employeeService in your case.

Put simply: with @RemoteServiceRelativePath you configure which URL the client code will call, and with <url-pattern> you configure at which URL your service "listens at"; and you have to make them match in order to make them talk to each other.

Upvotes: 1

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