Getting Started with GWT RequestFactory - google-app-engine

Question

I'm new to GWT. I've manage to do the tutorial about how to build the simple StockWatcher application.
Now, I want to load the data from the server. After reading about the many different ways to do it in GWT I decide to use RequestFactory because apparently it the most affective way to write maintainable application.
The problem is that there is no tutorial about RequestFactory and Eclipse is hard enough to manage when you know if, it even harder to manage when I'm using a new tool like GWT.
I've manage to find the different jars required for RequestFactory like
gwt-servlet.jar
gwt-servlet-deps.jar
requestfactory-server.jar
Now I get the following error:
java.lang.RuntimeException: The RequestFactory ValidationTool must be run for the com.google.gwt.sample.stockwatcher.shared.service.StockWatcherRequestFactory RequestFactory type
I've even found a direction for this as well: RequestFactoryInterfaceValidation
but it's still not working.
I've add the com.google.web.bindery.requestfactory.apt.ValidationTool to my build path and it seem to help (the message was gone) but then I got different error message.
I've push the source to github repository.
Any help will be great.
I'll try to make a post once I'll manage to get this working so other can use it.
Thank you,
Ido.

Answer 1

I figure this out. object is not an instance of declaring class means that we try to invoke a instance method on object which is not of the type the method is declared on.
My mistake was that in my ServiceLocator implementation I mistakably return an instance of my domain model object (StockQuote) instead of the DAO (StockQuoteDao). This cause RequestFactory code to try and invoke StockQuoteDao.getNum method on StockQuote instance.
Ido.

Answer 2

If you are using google plugin for eclipse use this
http://vivagwt.blogspot.com/2011/09/requestfactory-en-gwt-24.html
you need rebuild you project every time you change you requestcontext
note: gwt-servlet.jar is needed if you use RPC

Answer 3

Also you may automatically run RequestFactory ValidationTool with maven in compiling phase:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<forceJavacCompilerUse>true</forceJavacCompilerUse>
</configuration>
<dependencies>
<dependency>
<groupId>com.google.web.bindery</groupId>
<artifactId>requestfactory-apt</artifactId>
<version>2.6.1</version>
</dependency>
</dependencies>
</plugin>