java.lang.ClassNotFoundException on GWT async class in webapp

Question

I am developing a webapp using GWT. When I try to run it under eclipse ("Run as web application"), I get a java.lang.ClassNotFoundException pointing to my RPC async class.

I am experienced with development in Java but not with GWT. I did research this issue but the advice I found did not work for me, or I did not know how to apply it to my own webapp. I am hoping someone will be able to provide some insight.

The error

java.lang.ClassNotFoundException:gov.nist.toolkit.xdstools3.server.InterfaceClientServerImpl
--- stack trace of some more Jetty and GWT stuff that fails because of the error above ---

javax.servlet.UnavailableException: gov.nist.toolkit.xdstools3.server.InterfaceClientServerImpl
--- same thing ---

My implementation

I implemented the RPC logic:

client > InterfaceClientServer
       > InterfaceClientServerAsync
server > InterfaceClientServerImpl

and modified the web.xml to point to my service class.

InterfaceClientServer.java

package gov.nist.toolkit.xdstools3.client;

import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;

@RemoteServiceRelativePath("service")
public interface InterfaceClientServer extends RemoteService {
    public void logMeIn(String username, String password);
}

InterfaceClientServerAsync.java

package gov.nist.toolkit.xdstools3.client;

import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;

public interface InterfaceClientServerAsync {

    public void logMeIn(String username, String password, AsyncCallback<Void> callback);
}

InterfaceClientServerImpl.java

package gov.nist.toolkit.xdstools3.server;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import gov.nist.toolkit.xdstools3.client.InterfaceClientServer;

public class InterfaceClientServerImpl extends RemoteServiceServlet implements InterfaceClientServer {
    private static final long serialVersionUID = 1L;

    public void logMeIn(String username, String password){
        Caller.getInstance().logMeIn(username, password);
    }
}

web.xml

    <web-app>
    <display-name>Document Sharing Toolkit</display-name>

    <!-- Default page to serve -->
    <welcome-file-list>
        <welcome-file>Xdstools3.html</welcome-file>
    </welcome-file-list>

    <!-- Example servlet loaded into servlet container -->
    <servlet>
        <servlet-name>InterfaceClientServer</servlet-name>
        <servlet-class>gov.nist.toolkit.xdstools3.server.InterfaceClientServerImpl</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>InterfaceClientServer</servlet-name>
        <url-pattern>/xdstools3/service</url-pattern>
    </servlet-mapping>

</web-app>

Main tutorial I used

http://www.gwtproject.org/doc/latest/tutorial/RPC.html

Similar issues

I also found a few similar issues on Stackoverflow, such as this one: GWT question on RPC. This post would suggest that something is wrong with my web.xml and the linking to the async class, but I could not figure out what.

Other technologies used and versions

In case it ends up being relevant: GWT 2.5.1, Maven (m2e), Smartgwt.

Any help will be very welcome.

Answer 1

Server side classes may not be compiled.

Please ensure server side classes are present under target. Check your project's class-path also.

---

Please confirm from below screenshots:

• WAR directory src/main/webapp
• Launch and deploy from this directory is unchecked
• Default output folder project/target/classes