Description
Andy Wilkinson opened SPR-15582 and commented
Consider this application that uses Guava's ImmutableList:
package com.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.google.common.collect.ImmutableList;
@SpringBootApplication
@RestController
public class Unhelpful415Application {
public static void main(String[] args) {
SpringApplication.run(Unhelpful415Application.class, args);
}
@RequestMapping(path="create", method=RequestMethod.POST, consumes=MediaType.APPLICATION_JSON_UTF8_VALUE)
public String create(@RequestBody MyPojo pojo) {
return "Created";
}
public static class MyPojo {
private ImmutableList<String> things;
public ImmutableList<String> getThings() {
return things;
}
public void setThings(ImmutableList<String> things) {
this.things = things;
}
}
}
A POST to /create results in a 415 response (application/json is not supported). This is arguably wrong as JSON is supported and there's nothing that the client can do to fix the problem. It's actually the server that is at fault due to using ImmutableList and not configuring Jackson's Guava module. In my opinion, a 5xx response would be more appropriate.
The problem is exacerbated by the fact that Spring Framework 4.3 provides no further diagnostics for the failure. Arguably this is a regression as, with 4.2, a helpful warning message was logged:
2017-05-24 09:53:10.135 WARN 74298 --- [nio-8080-exec-5] .c.j.MappingJackson2HttpMessageConverter : Failed to evaluate Jackson deserialization for type [simple type, class com.example.Unhelpful415Application$MyPojo]: com.fasterxml.jackson.databind.JsonMappingException: Can not find a deserializer for non-concrete Collection type [collection type; class com.google.common.collect.ImmutableList, contains [simple type, class java.lang.String]]
This was removed by the changes for #18735. Enabling debug logging for org.springframework.http.converter.json doesn't provide any more information (and I don't think it should be necessary anyway).
Affects: 4.3.8
Reference URL: #18735
Issue Links:
- MappingJackson2HttpMessageConverter should not always log a warning [SPR-14163] #18735 MappingJackson2HttpMessageConverter should not always log a warning