RPC includes three types: httpService, WebService, and RemoteObject.
HttpService and WebService can communicate with the business logic layer without passing through the data service layer. The RemoteObject must pass through the data service layer. HttpService and WebService have security restrictions, which are caused by FP. To put it simply, if the Flex application needs to obtain data from the external Domain Server for cross-origin access, FP first needs to check whether the external Domain Server has deployed the allowed source domain (that is, the domain where the flex application is deployed) the accessed crossdomain. xml file. Specifically, if the Flex application deployed on DomainA needs to obtain the Web services provided by DomainB, corssdomain must be deployed in the root directory of DomainB's Web server. xml file, and configure in the file to allow access to the DomainA application. Generally, we cannot deploy crossdomain in an external domain. xml file. In this case, the LiveCycle Data Service proxy Service can be used as an intermediary to bypass the FP security mechanism and the proxy FP can access the external Domain Server. This is the proxy Service of LiveCycle Data Service. The RPC service is synchronous, while the message service is asynchronous.
