CODEWITHSUNDEEP
javaspring-bootexception
user6440081
user6440081

Reputation:

Error: Missing return statement when throwing a new ResponseStatusException in method

My IDE would show the error "missing return statement" within the catch-block when trying to throw a new exception within a method instead of throwing it directly.

Minified sample of the REST controller:

@RestController
public class RootController {
  protected final Logger log = Logger.getLogger("myLogger");

  @PostMapping(
    value={"sample/",
           "sample/123"},
    consumes = MediaType.APPLICATION_JSON_VALUE,
    produces = MediaType.APPLICATION_JSON_VALUE)
  public @ResponseBody Object getFileContentPost (@RequestBody Request payload) {
    return checkPayloadAndRespond(payload.getFileName());
  }

  private Object checkPayloadAndRespond(String fileName) throws ResponseStatusException {
    if (StringUtils.isEmpty(fileName))
      logErrorAndThrowResponseException(HttpStatus.BAD_REQUEST, "Field fileName is empty or missing!", null);

    try {
      ObjectMapper mapper = new ObjectMapper();
      return mapper.readValue("/static/json/" + fileName , Object.class);
    } catch (IOException e) {
      //line causing ERROR "missing return statement":
      logErrorAndThrowResponseException(HttpStatus.INTERNAL_SERVER_ERROR, "Could not parse file!, e);
    }
  }

  private void logErrorAndThrowResponseException(HttpStatus status, String reason, @Nullable Throwable cause) throws ResponseStatusException {
    log.error("Error occurred: " + reason + ", returning status: " + status);
    throw new ResponseStatusException(status, reason, cause);
  }


}

Working sample: if I use the throw new statement directly without method:

@RestController
public class RootController {
  protected final Logger log = Logger.getLogger("myLogger");

  @PostMapping(
    value={"sample/",
           "sample/123"},
    consumes = MediaType.APPLICATION_JSON_VALUE,
    produces = MediaType.APPLICATION_JSON_VALUE)
  public @ResponseBody Object getFileContentPost (@RequestBody Request payload) {
    return checkPayloadAndRespond(payload.getFileName());
  }

  private Object checkPayloadAndRespond(String fileName) throws ResponseStatusException {
    if (StringUtils.isEmpty(fileName))
      throw new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "Field fileName is empty or missing!", e);

    try {
      ObjectMapper mapper = new ObjectMapper();
      return mapper.readValue("/static/json/" + fileName , Object.class);
    } catch (IOException e) {
      throw new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "Could not parse response file!", e);
    }
  }

}

What is the best way to resolve this?

All I want to do is to actually create a log whenever a ResponseStatusException is thrown.

Thanks in advance.

Upvotes: 0

Views: 203

Answers (1)

user6440081
user6440081

Reputation:

So I guess the void-return-type is causing the issue.

I resolved it for now by returning an actual response which I then throw:

  private Object checkPayloadAndRespond(String fileName) throws ResponseStatusException {
    if (StringUtils.isEmpty(fileName))
      throw logErrorAndThrowResponseException(HttpStatus.BAD_REQUEST, "Field fileName is empty or missing!", null);

    try {
      ObjectMapper mapper = new ObjectMapper();
      return mapper.readValue("/static/json/" + fileName , Object.class);
    } catch (IOException e) {
throw logErrorAndThrowResponseException(HttpStatus.INTERNAL_SERVER_ERROR, "Could not parse file!, e);
    }
  }

  private ResponseStatusException logErrorAndThrowResponseException(HttpStatus status, String reason, @Nullable Throwable cause) {
    log.error("Error occurred: " + reason + ", returning status: " + status);
    return new ResponseStatusException(status, reason, cause);
  }


}

Upvotes: 0

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