resolveRequestBody algorithm does not take into account ConversionService when determining if binding is possible [SPR-6729]

[spring-projects-issues]

Keith Donald opened SPR-6729 and commented

I noticed this when using @RequestBody on an Account JavaBean @Controller parameter, when the ContentType of my POST /accounts request was "application/x-www-form-urlencoded". In this case, the resolved FormHttpMessageConverter is only capable of reading a MultiValueMap, not an Account, so I get a 415 back due to a HttpMediaTypeNotSupportedException. However, the ConversionService configured with Spring MVC may be capable of mapping a MultiValueMap to a JavaBean, but it is never queried inside resolveRequestBody of AnnotationMethodHandlerAdapter. If the ConversionService is capable of such a mapping, should it be invoked to allow the Account binding to succeed? Or should it be the sole responsibility of the MessageConverter to determine if binding is possible?

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Affects: 3.0 GA

Issue Links:

• Clarify use of "x-www-form-urlencoded" in reference documentation [SPR-8415] #13063 Clarify use of "x-www-form-urlencoded" in reference documentation
• MappingJacksonHttpMessageConverter's ObjectMapper does not use ConversionService when binding JSON to JavaBean properties [SPR-6731] #11397 MappingJacksonHttpMessageConverter's ObjectMapper does not use ConversionService when binding JSON to JavaBean properties

1 votes, 1 watchers

[spring-projects-issues]

Keith Donald commented

Given the relationship with #11397, I would tend to think whether the ConversionService was used or not would be an implementation detail of the MessageConverter. Something to think about.

[spring-projects-issues]

Bryan Kelly commented

Is there currently a work around to this issue when using 3.0.5 of spring-web?

[spring-projects-issues]

Rossen Stoyanchev commented

Turning a MultiValueMap into a typed object seems more like data binding. You could do:

public void update(@RequestBody MultiValueMap<String, String> map) {
  Account account = new Account();
  WebDataBinder binder = new WebDataBinder(account);
  binder.bind(map.toSingleValueMap();
  // ...
}

If you have this often enough, consider creating your own annotation and implementing a custom HandlerMethodArgumentResolver probably extending from AbstractMessageConverterMethodProcessor.

[spring-projects-issues]

Rossen Stoyanchev commented

Better yet, just use @ModelAttribute! (see #13063)