java - getting ClassCastException when iterating parameter ArrayList received from put -

using restlet, trying receive list of class foo through put method

    class foo {         public string name;         public int age;     }   public class bar extends serverresource  {        @put     public string update(arraylist<foo> foos) {          string names = "";                 try {             (foo foo : foos ) {                 names += ","+foo.name;             }         } catch (exception e) {             e.printstacktrace();         }         return names;     } } 

however when sending json

[     {         "name":"bar",         "age":1     },     {         "age":27,         "name":"baz"     } ] 

i getting exception @ loop first line

java.lang.classcastexception: java.util.linkedhashmap cannot cast foo     @ bar.update(bar.java:55)     @ sun.reflect.nativemethodaccessorimpl.invoke0(native method)     @ sun.reflect.nativemethodaccessorimpl.invoke(nativemethodaccessorimpl.java:57)     @ sun.reflect.delegatingmethodaccessorimpl.invoke(delegatingmethodaccessorimpl.java:43)     @ java.lang.reflect.method.invoke(method.java:606)     @ org.restlet.resource.serverresource.dohandle(serverresource.java:503)     @ org.restlet.resource.serverresource.put(serverresource.java:1275)     @ org.restlet.resource.serverresource.dohandle(serverresource.java:583)     @ org.restlet.resource.serverresource.donegotiatedhandle(serverresource.java:649)     @ org.restlet.resource.serverresource.doconditionalhandle(serverresource.java:348)     @ org.restlet.resource.serverresource.handle(serverresource.java:952)     @ org.restlet.resource.finder.handle(finder.java:246)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.router.dohandle(router.java:431)     @ org.restlet.routing.router.handle(router.java:648)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.engine.application.statusfilter.dohandle(statusfilter.java:155)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.engine.compositehelper.handle(compositehelper.java:211)     @ org.restlet.engine.application.applicationhelper.handle(applicationhelper.java:84)     @ org.restlet.application.handle(application.java:381)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.router.dohandle(router.java:431)     @ org.restlet.routing.router.handle(router.java:648)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.routing.router.dohandle(router.java:431)     @ org.restlet.routing.router.handle(router.java:648)     @ org.restlet.routing.filter.dohandle(filter.java:159)     @ org.restlet.routing.filter.handle(filter.java:206)     @ org.restlet.engine.compositehelper.handle(compositehelper.java:211)     @ org.restlet.component.handle(component.java:392)     @ org.restlet.server.handle(server.java:516)     @ org.restlet.engine.serverhelper.handle(serverhelper.java:72)     @ org.restlet.engine.adapter.httpserverhelper.handle(httpserverhelper.java:152)     @ org.restlet.ext.servlet.serverservlet.service(serverservlet.java:1089)     @ javax.servlet.http.httpservlet.service(httpservlet.java:848)     @ org.eclipse.jetty.servlet.servletholder.handle(servletholder.java:684)     @ org.eclipse.jetty.servlet.servlethandler.dohandle(servlethandler.java:501)     @ org.eclipse.jetty.server.handler.scopedhandler.handle(scopedhandler.java:137)     @ org.eclipse.jetty.security.securityhandler.handle(securityhandler.java:557)     @ org.eclipse.jetty.server.session.sessionhandler.dohandle(sessionhandler.java:231)     @ org.eclipse.jetty.server.handler.contexthandler.dohandle(contexthandler.java:1086)     @ org.eclipse.jetty.servlet.servlethandler.doscope(servlethandler.java:428)     @ org.eclipse.jetty.server.session.sessionhandler.doscope(sessionhandler.java:193)     @ org.eclipse.jetty.server.handler.contexthandler.doscope(contexthandler.java:1020)     @ org.eclipse.jetty.server.handler.scopedhandler.handle(scopedhandler.java:135)     @ org.eclipse.jetty.server.handler.contexthandlercollection.handle(contexthandlercollection.java:255)     @ org.eclipse.jetty.server.handler.handlercollection.handle(handlercollection.java:154)     @ org.eclipse.jetty.server.handler.handlerwrapper.handle(handlerwrapper.java:116)     @ org.eclipse.jetty.server.server.handle(server.java:370)     @ org.eclipse.jetty.server.abstracthttpconnection.handlerequest(abstracthttpconnection.java:494)     @ org.eclipse.jetty.server.abstracthttpconnection.content(abstracthttpconnection.java:982)     @ org.eclipse.jetty.server.abstracthttpconnection$requesthandler.content(abstracthttpconnection.java:1043)     @ org.eclipse.jetty.http.httpparser.parsenext(httpparser.java:865)     @ org.eclipse.jetty.http.httpparser.parseavailable(httpparser.java:240)     @ org.eclipse.jetty.server.asynchttpconnection.handle(asynchttpconnection.java:82)     @ org.eclipse.jetty.io.nio.selectchannelendpoint.handle(selectchannelendpoint.java:667)     @ org.eclipse.jetty.io.nio.selectchannelendpoint$1.run(selectchannelendpoint.java:52)     @ org.eclipse.jetty.util.thread.queuedthreadpool.runjob(queuedthreadpool.java:608)     @ org.eclipse.jetty.util.thread.queuedthreadpool$3.run(queuedthreadpool.java:543)     @ java.lang.thread.run(thread.java:744) 

any idea how can iterate through list , getting foo item attributes ?

annotate foo @xmlrootelement. otherwise json serializer not know class want unserialize.