I have an enum defined as:

public static enum State {
    
    @JsonProperty("At Rest")
    AT_REST,
    
    @JsonProperty("In Motion")
    IN_MOTION, 
    
    @JsonProperty("Stalled")
    STALLED;        
} 

So, the server produces "At Rest" when Jackson serializes the AT_REST enum into JSON. Similarly, Jackson deserializes "At Rest" into AT_REST when the client passes JSON to the server. For example:

@GetMapping()
public State[] getAllStates() {
 return State.values(); //returns JSON ["At Rest", "In Motion", "Stalled"]
}

@PostMapping()
public void saveState(@ResponseBody State state /*when client sends "At Rest", it gets converted into Enum*/) { 
 //save state
}

I also have a search GET endpoint. The client calls it with a "state" query parameter such https://localhost/search?state=At Rest. Since the query parameter value is not JSON, I have a Spring converter:

@Component
public class StringToStateConverter implements Converter<String, State> {
    
    @Override
    public State convert(String description) {
        if ("At Rest".equals(description)) {
            return State.AT_REST;
        } else if ("In Motion".equals(description)) {
            return State.IN_MOTION;
        } else if ("Stalled".equals(description)) {
            return State.STALLED;
        } else {
            return null;
        }
    }
    
}

Is it possible to have Spring use JsonProperty when deserializing a query param? If not, how can I avoid having the String description in multiple places in my code? I prefer not to make a description field in the enum since this is really just for client display.

CodePudding user response：

Is it possible to have Spring use JsonProperty when deserializing a query param?

Yes.

@Component
@RequiredArgsConstructor
public class StringToStateConverter implements Converter<String, State> {
    
    private final ObjectMapper mapper;
    
    @Override
    public State convert(String description) {
        
        try {
            return mapper.readValue("\""   description   "\"", State.class);
        } catch (JsonProcessingException e) {
            // code to return error to client
        }
}