Hi Let's remember that when we have one RestServlet in a war no attribute configuration should be configured.
Usually there is no reason to register more then one RestServlet in a single war, one engine can handle many resources and even many applications. In the example below, I would recommend to register the all resources and providers in a single application or to register both application in single engine. Regarding the concern Bryant mention about having the Wink libraries in the application servers shared libs, I do not see the problem there since each requestProcessor is saved on a different srevletContext. We could have generate a random attribute name and use it but this would cause problem. In the Spring for instance the RequestProcessor is been initiate by the spring framework and is been set on the ServletContext by a listener. In such situation the attribute name need to be synchronized between the listener who put the requestProcessor on the ServletContext and the RestServlet who try to get it from there. Something that we can improve however is to be able to register multiple application classes from the web.xml. Today if you want to register several applications you need either to use the SimpleApplication to load resources/providers from several files, or to register the additional applications from java code. We should enabling specifying the application classes in the web.xml, mybe with a semicolon between the different classes. Regarding Nick question, I do not see a reason why 2 servlets would not be able to work with the same engine, though we did not try it. in such case only the first servelt will init the requestProcessor. I believe that what happened in Bryant test. --Eli From: Nicholas L Gallardo [mailto:[email protected]] Sent: Thursday, July 02, 2009 5:03 PM To: [email protected] Subject: Re: Multiple RestServlets in single web application? +1 to auto populating a new parameter and enabling it by default. Question, does the runtime work when two servlets share the same request processor? My impression from Bryant's note was no, but Eli seemed to indicate that they did. Or, is it that only one servlet needs to be fired because the config that existed for both applications is now smashed together? Looking at how the servlets are defined in Bryant's example, it seems more intuitive to have the configs separated out on a per servlet basis. If I want them together, then I can just add the resources/providers to a single Application class and be done with it. -Nick Nicholas Gallardo WebSphere - REST & WebServices Development [email protected] Phone: 512-286-6258 Building: 903 / 5G-016 [cid:[email protected]]Bryant Luk <[email protected]> Bryant Luk <[email protected]> 07/02/2009 08:51 AM Please respond to [email protected] To [email protected] cc Subject Re: Multiple RestServlets in single web application? Hi Eli, Just curious why we need the application developer to add that parameter. Is there any way that we can autogenerate that parameter within the runtime? The reasons why I think we should autogenerate: 1) Application portability. If other implementations take their JAX-RS application and switch to Wink (or start with Wink), the first impression may be that we don't work out of the box. 2) I haven't tested this but if we use Wink as a shared library across a container's applications (such as Geronimo/WebSphere), I think this would cause some administration headaches since every parameter value (I'm assuming) has to be unique. Some application developers might not communicate their unique attribute names, and this would be a really hard thing to find out when an application doesn't work correctly. I think we can have it as an optional attribute if you want to use the same RequestProcessor across two servlet instances, just that by default, we generate a unique one per servlet instance. Thoughts? On Thu, Jul 2, 2009 at 3:34 AM, Baram, Eliezer<[email protected]> wrote: > Hi Bryant > The RestServlet stores the requestProcessor on the servletContext, by default > it saves it under an attribute named RequestProcessor.class.getName() > > If you register more then one servlet and you want each to have a separate > RequestProcessor you need to indicate the RestServlet to save the > RequestProcessor under a different attribute. > > You can specify the attribute name by setting the > "symphony.requestProcessorAttribute" init parameter of the RestServlet. > See modification below. > > --Eli > > > > -----Original Message----- > From: Bryant Luk [mailto:[email protected]] > Sent: Thursday, July 02, 2009 2:09 AM > To: [email protected] > Subject: Multiple RestServlets in single web application? > > Hi, > > Does the RestServlet support multiple servlet instances in the same > web application? > > It seems that only the first servlet (in alphabetical order) is fired > up correctly. If I have two instances of the servlet, say > MessageBodyWriterExceptions and MessageBodyReaderExceptions, only > MessageBodyReaderExceptions seems to work. If I then rename > MessageBodyReaderExceptions to "Z" (or comment out the servlet > definition), then my MessageBodyWriterExceptions servlet JAX-RS app > works. > > My web.xml: > > <web-app> > <display-name>Archetype Created Web Application</display-name> > <servlet> > <servlet-name>MessageBodyWriterExceptions</servlet-name> > > <servlet-class>org.apache.wink.server.internal.servlet.RestServlet</servlet-class> > <init-param> > <param-name>javax.ws.rs.Application</param-name> > > <param-value>org.apache.wink.jaxrs.test.providers.writerexceptions.Application</param-value> > </init-param> > <load-on-startup>1</load-on-startup> > </servlet> > <servlet> > <servlet-name>MessageBodyReaderExceptions</servlet-name> > > <servlet-class>org.apache.wink.server.internal.servlet.RestServlet</servlet-class> > <init-param> > <param-name>javax.ws.rs.Application</param-name> > > <param-value>org.apache.wink.jaxrs.test.providers.readerexceptions.Application</param-value> > </init-param> > [E.B] <init-param> > <param-name>symphony.requestProcessorAttribute</param-name> > <param-value>requestProcessorAttribute_2</param-value> > </init-param> > <load-on-startup>1</load-on-startup> > </servlet> > <servlet-mapping> > <servlet-name>MessageBodyWriterExceptions</servlet-name> > <url-pattern>/writerexceptions/*</url-pattern> > </servlet-mapping> > <servlet-mapping> > <servlet-name>MessageBodyReaderExceptions</servlet-name> > <url-pattern>/readerexceptions/*</url-pattern> > </servlet-mapping> > </web-app> > > -- > > - Bryant Luk > -- - Bryant Luk
