For Flex+java use remoteobject communication error Channel.Connect.Failed error NetConnection.Call.Failed 404

When using RemoteObject for Java calls in flex today, the error

[RPC Fault faultstring= "Send failed" faultcode= "Client.Error.MessageSend" faultdetail= "Channel.Connect.Failed Error NetConnection.Call.Failed:HTTP:Status 404:url: ' HTTP://LOCALHOST:8080/UNITCITY/MESSAGEBROKER/AMF ', so Baidu, online saying a lot , up to the following two scenarios:

First case:

[RPC Fault faultstring= "Send failed" faultcode= "Client.Error.MessageSend" faultdetail= "Channel.Connect.Failed Error NetConnection.Call.Failed:HTTP:Status 404:url: ' HTTP://LOCALHOST:8889/WEBCONTENT/MESSAGEBROKER/AMF ' "]

When the URL is webcontent instead of the project name: This is mainly due to the setting of the context root problem, modify the project name can be;

Method: Right-click Project-Properties-flex Server-context Root (/project name)

Second case:

[RPC Fault faultstring= "Send failed" faultcode= "Client.Error.MessageSend" faultdetail= "Channel.Connect.Failed Error NetConnection.Call.Failed:HTTP:Status 404:url: ' HTTP://LOCALHOST:8080/UNITCITY/MESSAGEBROKER/AMF ' "]

In response to this situation, it is said that Tomcat is a problem, some say that the remoteobject call needs to add endpoint= "http://localhost:8080/project name/MESSAGEBROKER/AMF";

<mx:remoteobject id= "Tpublicuserservice" destination= "Tpublicuserservice" endpoint= "http://localhost:8080/Project name/ MESSAGEBROKER/AMF ">

</mx:RemoteObject>

And I have configured this at the time of invocation, but there is still a problem, and that is the third case,

The third case (my case):

So I went on to find the reason: Because I only configured the Flex listener in Web. XML, and forgot to configure the servlet, the workaround is as follows:

It is also said that adding the following can be, specifically no test:

<listener>
<listener-class>flex.messaging.HttpFlexSession</listener-class>
</listener>
<servlet>
<servlet-name>MessageBrokerServlet</servlet-name>
<servlet-class>flex.messaging.MessageBrokerServlet</servlet-class>
<init-param>
<param-name>services.configuration.file</param-name>
<param-value>/WEB-INF/flex/services-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>MessageBrokerServlet</servlet-name>
<url-pattern>/messagebroker/*</url-pattern>
</servlet-mapping>

For Flex+java use remoteobject communication error Channel.Connect.Failed error NetConnection.Call.Failed 404