We are trying to put Spring Cloud Netflix into production environment. For now we encounter a problem about business logic error handling.
We're using Feign as HTTP REST client. Microservice A needs to invoke microservice B which is deployed in different JVM(or physical server). Microservice B may return some error message which belongs to business. For instance A needs to query order information from B but the order ID may not exist so B has to return the error message that tells A this order doesn't exist. A has to do if-else judgement from the return message to determine if there are erorrs, then code will be like the following snippet:
//remoteServiceA is an interface annotated with @FeignClient
resultA = remoteServiceA.foo();
if (resultA.hasError) {
} else {
}
resultB = remoteServiceB.foo();
if (resultB.hasError) {
} else {
}
// ... ...
There are so many if-else so that it's not graceful enough. What we want is remoteServieA.foo() can throw a self-defined runtime exception such as OrderNotExistException. Any idea to achieve this goal?
I've solved this problem.
I customized the ErrorDecoder component of Feign, in which I can throw my own exception according to the HTTP original response.