I am working on an application that requires me construct Error 404 and Error 500 manually. My application is client application --> Core --> Wrapper --> Adaptor --> database. All the communications between the Core and the Wrapper and between the Wrapper and Adapter use REST. And I am working on the Wrapper module.
When the Wrapper contacts the Adaptor to request for some data, if resource-not-found encountered, I am supposed to put 404 status code in the HTTP header and return it to the "core". All other exception internal to the Wrapper, I am supposed to put 500 status code in the HTTP header.
Would you guide me as to how to construct the code please?
For example, I think that I can do something like: ex.getCause(); But, how do I know it is resource-not-found so that I can construct the header and put 404 there? Thank you very much.
Interception is a concept using which you can execute some code before/after or around your actual service implementation. Implementation of Interceptors & how to use them is specific to the library that you are using to implement your web-services. Look this into the documentation of the library that you are using. I am known to apache CXF, & for that i can give reference as - http://cxf.apache.org/docs/interceptors.html
Yes it can be done, we just have to figure out how.