grails webservices returning an object List

Question

I'm trying to expose a webservice via grails & cxf grails plugin.

this is the skeleton of the webservice:

class IssueService {

    static expose=['cxf']

    def List issueList(){
     def list = Issue.list()

     return list
    }

    def Issue singleIssue(id){
     def currentIssue = Issue.findById(id)
     return currentIssue
    }


}

the method "singleIssue" works correctly but the method "issueList" throws a jaxb marshall exception

org.apache.cxf.interceptor.Fault: Marshalling Error: java.util.ArrayList is not known to this context
    at org.apache.cxf.jaxb.JAXBEncoderDecoder.marshall(JAXBEncoderDecoder.java:159)
    at org.apache.cxf.jaxb.io.DataWriterImpl.write(DataWriterImpl.java:169)
    at org.apache.cxf.interceptor.AbstractOutDatabindingInterceptor.writeParts(AbstractOutDatabindingInterceptor.java:105)
    at org.apache.cxf.interceptor.BareOutInterceptor.handleMessage(BareOutInterceptor.java:68)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236)
    at org.apache.cxf.interceptor.OutgoingChainInterceptor.handleMessage(OutgoingChainInterceptor.java:74)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236)
    at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:104)
    at org.apache.cxf.transport.servlet.ServletDestination.invoke(ServletDestination.java:99)
    at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:452)
    at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:159)
    at org.apache.cxf.transport.servlet.AbstractCXFServlet.invoke(AbstractCXFServlet.java:220)
    at org.apache.cxf.transport.servlet.AbstractCXFServlet.doGet(AbstractCXFServlet.java:158)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at org.apache.cxf.transport.servlet.AbstractCXFServlet.service(AbstractCXFServlet.java:211)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1124)
    at org.codehaus.groovy.grails.web.mapping.filter.UrlMappingsFilter.processFilterChain(UrlMappingsFilter.java:263)
    at org.codehaus.groovy.grails.web.mapping.filter.UrlMappingsFilter.doFilterInternal(UrlMappingsFilter.java:205)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
    at org.codehaus.groovy.grails.web.sitemesh.GrailsPageFilter.obtainContent(GrailsPageFilter.java:221)
    at org.codehaus.groovy.grails.web.sitemesh.GrailsPageFilter.doFilter(GrailsPageFilter.java:126)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
    at org.codehaus.groovy.grails.web.servlet.filter.GrailsReloadServletFilter.doFilterInternal(GrailsReloadServletFilter.java:101)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
    at org.codehaus.groovy.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:65)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:236)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:361)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:324)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:534)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:864)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:533)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:207)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:403)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:522)
Caused by: javax.xml.bind.MarshalException
 - with linked exception:
[javax.xml.bind.JAXBException: java.util.ArrayList is not known to this context]
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:318)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:244)
    at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:75)
    at org.apache.cxf.jaxb.JAXBEncoderDecoder.writeObject(JAXBEncoderDecoder.java:444)
    at org.apache.cxf.jaxb.JAXBEncoderDecoder.marshall(JAXBEncoderDecoder.java:138)
    ... 48 more
Caused by: javax.xml.bind.JAXBException: java.util.ArrayList is not known to this context
    at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:246)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:261)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:144)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:189)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeBody(ElementBeanInfoImpl.java:315)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:322)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:72)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:494)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:315)
    ... 52 more
Caused by: javax.xml.bind.JAXBException: java.util.ArrayList is not known to this context
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getBeanInfo(JAXBContextImpl.java:621)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:141)
    ... 58 more

Similar exception is trown also if i make the method return an array of Issue Objects

to further clarify the problem:

package it.weservice.tools.bts

class TestService {

    static expose=['cxf']


    String[] testMethod(){
     def result = ["string1", "string2"]

     return result as String[]
    }


}

returns

org.apache.cxf.interceptor.Fault: Marshalling Error: [Ljava.lang.String; is not known to this context

Answer 1

I solved the problem exposing explicitly the webservice via

static expose=['cxfjax']

and by annotating the methods I want to expose with the @WebMethod annotation

Saluti