GWT RPC - Multiple RPC Services

Question

I'm having the problem of splitting up a large RPC service into smaller chunks. I found the basics here GWT RPC - Multiple RPC Services Per App , but I'm struggling with the implementation. I can't find any good guide, anywhere. I'm confused with the following part. (The goal is to split up one large RPC into two smaller ones)

I create a servlet class in the module xml file
in web.xml i create a servlet and one servlet-mapping with 2 servlet-urls. The first servlet is the 'main servlet' and is the same as in the module xml file. The second is an authentification servlet.
I have a sync and async interface for both servlets and an server side implementation for both servlets.
I create the servlets in the code with GWT.create(). I can call methods in the 'main servlet' without problems. But I can't call methods in the authentification servlet. When I try this I get the following error:

[ERROR] [project] - Unable to load module entry point class com.projects.client.Project (see associated exception for details)

com.google.gwt.user.client.rpc.ServiceDefTarget$NoServiceEntryPointSpecifiedException: Service implementation URL not specified
at com.google.gwt.user.client.rpc.impl.RemoteServiceProxy.doPrepareRequestBuilderImpl(RemoteServiceProxy.java:430)
at com.google.gwt.user.client.rpc.impl.RemoteServiceProxy.doInvoke(RemoteServiceProxy.java:368)
at com.google.gwt.user.client.rpc.impl.RemoteServiceProxy$ServiceHelper.finish(RemoteServiceProxy.java:74)
at com.projects.client.AuthService_Proxy.signIn(AuthService_Proxy.java:44)
at com.projects.client.Authentication.signIn(Authentication.java:38)
at com.projects.client.Project.onModuleLoad(Project.java:53)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)

15:48:13.877 [ERROR] [project] Failed to load module 'project' from user agent 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11' at 127.0.0.1:2588**

Please add the rest of the error (i.e. the "associated exception for details"). — Colin Alworth
Do you have @RemoteServiceRelativePath() declared on all the classes extending from RemoteService? — appbootup
This solved my problem, but now I got a new problem. For the idea in the above link to work my 'main servlet' needs to implement the interfaces of both servlets. But this means the 'main servlet' still has all methods in it. This was the main thing I was trying to avoid. The only solution I can think of is to implement both interfaces and redirect calls to the second servlet. But this is not what I expected from the idea of seperating the rpc. — Vjeetje

Colin Alworth Colin Alworth · Accepted Answer · 2013-01-02T17:13:20

From your link:

I believe I'd have to make a new servlet for each one.

Not necessarily.

Which is to say, yes, you could have just one servlet for all of the interfaces, but this isn't required. You certainly may have just one servlet that implements all of the given interfaces, but as long as each RPC interface has a @RemoteServiceRelativePath that points to a different URL, and each URL is mapped in your web.xml to a different servlet, each of those servlets need only implement that one interface that is pointed at it.

GWT RPC - Multiple RPC Services

1 Answers