SpringBoot和ProtoBuf:如何通过在响应体中添加错误来使HTTP400更有用

Question

我们使用ProtobufJsonFormatHttpMessageConverter将JSON请求体解析为REST端点中的原型：

@Bean
ProtobufHttpMessageConverter protobufHttpMessageConverter() {
return new ProtobufJsonFormatHttpMessageConverter(
JsonFormat.parser(), JsonFormat.printer().includingDefaultValueFields());
}

在请求中，假设有一个枚举，如果值中有拼写错误，例如

{
"type": "ELEPHAANT"
}

我得到一个带有空正文的HTTP 400响应，控制台有：

DEBUG o.s.w.s.DispatcherServlet - POST "/foo-search", parameters={}
DEBUG o.s.w.s.m.m.a.RequestMappingHandlerMapping - Mapped to com.foobar.MasterController#sample(SampleRequest)
DEBUG o.s.w.s.m.m.a.ServletInvocableHandlerMethod - Could not resolve parameter [0] in public com.foobar.models.ResponseOuterClass$SampleResponse com.foobar.MasterController.Sample(com.foobar.models.SampleRequestOuterClass$SampleRequest): I/O error while reading input message; nested exception is com.google.protobuf.InvalidProtocolBufferException: Invalid enum value: ELEPHAANT for enum type: SampleRequest.Filter.Type
DEBUG o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Using @ExceptionHandler com.foobar.advice.ExceptionHandlerAdvice#handleException(Exception, WebRequest)
DEBUG o.s.w.s.m.m.a.HttpEntityMethodProcessor - No match for [*/*], supported: []
DEBUG o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Resolved [org.springframework.http.converter.HttpMessageNotReadableException: I/O error while reading input message; nested exception is com.google.protobuf.InvalidProtocolBufferException: Invalid enum value: ELEPHAANT for enum type: ObtSampleRequest.Filter.Type]
DEBUG o.s.w.s.DispatcherServlet - Completed 400 BAD_REQUEST

这个问题在控制台日志中很清楚：

Invalid enum value: ELEPHAANT for enum type: ObtSampleRequest.Filter.Type

我是否可以通过包含上述信息使响应主体更加有用？

Answer 1

你可以想出一个@RestControllerAdvice

@RestControllerAdvice
public class MyAdvice {
@ExceptionHandler(HttpMessageNotReadableException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public String handle(HttpMessageNotReadableException e) {
return e.getMessage(); // or return a nice error object with the nested exception's msg
}
}