[Spring MVC] Problem handling HTTP Request with differents parameters

[AndreaNobili]

Hello,
I am going crazy trying to handle the following situation:

In a view I have the following 3 links that all generate an HTTP Request towards the "/mapping/parameter" folder. These links differ from each other for the parameter passed, so the first one pass a parameter named foo, the second one pass a parameter named foo2 and the last one pass no parameter.

			<li>
				<a id="byParameter" class="textLink" href="<c:url value="/mapping/parameter?foo=bar" />">By path, method, and presence of parameter</a>
			</li>
			
			<!-- PERSONALE -->
			<li>
				<a id="byParameter2" class="textLink" href="<c:url value="/mapping/parameter?foo2=blabla" />">(PERSONALE) By path, method, and presence of parameter with value="blabla"</a>
			</li>
			
			<li>
				<a id="byNotParameter" class="textLink" href="<c:url value="/mapping/parameter" />">By path, method, and not presence of parameter</a>
			</li>

Now, in my controller class, I would handle this situation using 3 different methods, so I added the following methods to my controller:

	@RequestMapping(value="/mapping/parameter", method=RequestMethod.GET, params="foo")
	public @ResponseBody String byParameter() {
		System.out.println("foo");
		return "Mapped by path + method + presence of query parameter!";
	}
	
	@RequestMapping(value="/mapping/parameter", method=RequestMethod.GET, params="foo2")
	public @ResponseBody String byParameter2(@RequestParam("foo2") String foo2) {
		System.out.println("foo2");
		return "Mapped by path + method + presence of query parameter! (MappingController). Parameter value = " + foo2;
		}
	
	@RequestMapping(value="/mapping/parameter", method=RequestMethod.GET, params="!foo, !foo2")
	public @ResponseBody String byParameterNegation() {
		System.out.println("NO foo NO foo2");
		return "Mapped by path + method + not presence of query parameter!";
	}

The problem is that in this way is handled only the !foo, !foo2 case and if I click on the first link (the one with the parameter naming foo) I obtain the following error in the stack trace:

nov 24, 2012 9:10:29 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [appServlet] in context with path [/spring-mvc-showcase] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8080/spring-mvc-showcase/mapping/parameter': {public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameter(), public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameterNegation()}] with root cause
java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8080/spring-mvc-showcase/mapping/parameter': {public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameter(), public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameterNegation()}
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.lookupHandlerMethod(AbstractHan dlerMethodMapping.java:262)
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.getHandlerInternal(AbstractHand lerMethodMapping.java:212)
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.getHandlerInternal(AbstractHand lerMethodMapping.java:55)
at org.springframework.web.servlet.handler.AbstractHa ndlerMapping.getHandler(AbstractHandlerMapping.jav a:297)
at org.springframework.web.servlet.DispatcherServlet. getHandler(DispatcherServlet.java:1091)
at org.springframework.web.servlet.DispatcherServlet. getHandler(DispatcherServlet.java:1076)
at org.springframework.web.servlet.DispatcherServlet. doDispatch(DispatcherServlet.java:896)
at org.springframework.web.servlet.DispatcherServlet. doService(DispatcherServlet.java:856)
at org.springframework.web.servlet.FrameworkServlet.p rocessRequest(FrameworkServlet.java:917)
at org.springframework.web.servlet.FrameworkServlet.d oGet(FrameworkServlet.java:813)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:621)
at org.springframework.web.servlet.FrameworkServlet.s ervice(FrameworkServlet.java:798)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:722)
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invo ke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invo ke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBas e.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke( StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(A ccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invok e(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.servic e(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.p rocess(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnect ionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProce ssor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker( ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

And if I click on the second link (the one with the parameter naming foo) I obtain the following error in the stack trace:

nov 24, 2012 9:11:27 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [appServlet] in context with path [/spring-mvc-showcase] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8080/spring-mvc-showcase/mapping/parameter': {public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameter2(java.lang.String), public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameterNegation()}] with root cause
java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8080/spring-mvc-showcase/mapping/parameter': {public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameter2(java.lang.String), public java.lang.String org.springframework.samples.mvc.mapping.MappingCon troller.byParameterNegation()}
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.lookupHandlerMethod(AbstractHan dlerMethodMapping.java:262)
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.getHandlerInternal(AbstractHand lerMethodMapping.java:212)
at org.springframework.web.servlet.handler.AbstractHa ndlerMethodMapping.getHandlerInternal(AbstractHand lerMethodMapping.java:55)
at org.springframework.web.servlet.handler.AbstractHa ndlerMapping.getHandler(AbstractHandlerMapping.jav a:297)
at org.springframework.web.servlet.DispatcherServlet. getHandler(DispatcherServlet.java:1091)
at org.springframework.web.servlet.DispatcherServlet. getHandler(DispatcherServlet.java:1076)
at org.springframework.web.servlet.DispatcherServlet. doDispatch(DispatcherServlet.java:896)
at org.springframework.web.servlet.DispatcherServlet. doService(DispatcherServlet.java:856)
at org.springframework.web.servlet.FrameworkServlet.p rocessRequest(FrameworkServlet.java:917)
at org.springframework.web.servlet.FrameworkServlet.d oGet(FrameworkServlet.java:813)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:621)
at org.springframework.web.servlet.FrameworkServlet.s ervice(FrameworkServlet.java:798)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:722)
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invo ke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invo ke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBas e.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke( StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(A ccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invok e(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.servic e(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.p rocess(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnect ionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProce ssor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker( ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

Why? How can I resolve?

Thanks
Andrea

[Marten Deinum]

Please use [ code][/code ] tags for the stacktrace.

I suggest you take a look at the reference guide and the api docs of the RequestMapping annotation... Params takes an array... Each parameter should be an element in that array. You have a single element and that parameter is never present so you basically end up with 2 matches for each link you click...

So in short make it an array with 2 seperate elements.... ( params={"!foo", "!foo2"} )

[AndreaNobili]

Please use [ code][/code ] tags for the stacktrace.

I suggest you take a look at the reference guide and the api docs of the RequestMapping annotation... Params takes an array... Each parameter should be an element in that array. You have a single element and that parameter is never present so you basically end up with 2 matches for each link you click...

So in short make it an array with 2 seperate elements.... ( params={"!foo", "!foo2"} )

Ok,
thank you very much for your clear explanation, now it work well...now I am reading the API doc