RPC call returning List<String> fails

[jos]

I have an RPC call with a signature like public List<String> SomeCall
(SomeObj) { return anArrayList; } which failed.
Policy file was deployed and the file had ArrayList, true in the file.
The only real information available was the stack trace it left in
catalina.out (see below).

I'm running gwt1.52, a Spring/Hibernate stack on the back end with (a
probably early version of) gwt-sl. The problem manifested itself in
eclipse. When I changed the return value to String[] eveything worked
fine.

Does anyone know, is it not OK to use List<String> as a return
specifier?




2009-01-14 16:41:08,569 ERROR [org.apache.catalina.core.ContainerBase.
[Catalina].[localhost].[/geo]] - <Exception while dispatching incoming
RPC call>
javax.servlet.ServletException: Client did not send 158 bytes as
expected
at com.google.gwt.user.server.rpc.RPCServletUtils.readContentAsUtf8
(RPCServletUtils.java:148)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.readContent
(RemoteServiceServlet.java:335)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.doPost
(RemoteServiceServlet.java:77)
at org.gwtwidgets.server.spring.GWTRPCServiceExporter.handleRequest
(GWTRPCServiceExporter.java:169)
at
org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle
(HttpRequestHandlerAdapter.java:49)
at org.springframework.web.servlet.DispatcherServlet.doDispatch
(DispatcherServlet.java:874)
at org.springframework.web.servlet.DispatcherServlet.doService
(DispatcherServlet.java:808)
at org.springframework.web.servlet.FrameworkServlet.processRequest
(FrameworkServlet.java:476)
at org.springframework.web.servlet.FrameworkServlet.doPost
(FrameworkServlet.java:441)

[alex.d]

It is actually. I'm using a lot of structures like this(and more
complex) for data transfer. The problem ist somewhere else - do you
initialize your List properly?

[jos]

yes, new ArrayList<String> followed by several add("some string")

What's got me stuck is the backend saying it's waiting on 153 bytes
from the client, like it's not event fired off the RPC call yet

So List<> is OK, I don't need to use ArrayList<> ?

[alex.d]

I remember a thread not that long time ago where someone experienced
same trouble with "waiting on NNN bytes". I'm not sure what the
problem exactly was. Using List<String> is ok(but in case of some
black magic used - try it anyway ;-)

[jos]

OK, I've finally had a chance to look into this some more and updated
the gwt-sl.jar version I was using (fairly old as previously stated) I
downloaded the 0.1.5b (latest version still using Hibernate4GWT) and
put everything back to List<String> and it worked inside and outside
of eclipse. Given this was the only thing I changed, possibly a
problem in the old library.

Thanks for replies...

jos