Spring Boot Application: No converter found for return value of type

Question

I am writing a simple REST API according to this Spring-Boot tutorial. On my local dev machines (Ubuntu 15.04 and Windows 8.1) everything works like a charm.

I have an old 32-bit Ubuntu 12.04 LTS server lying around on which I wanted to deploy my REST service.

The starting log is ok, but as soon as I send a GET request to the /user/{id} endpoint, I get the following error:

java.lang.IllegalArgumentException: No converter found for return value of type: class ch.gmazlami.gifty.models.user.User

And then down the stacktrace:

java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.LinkedHashMap

The entire stacktrace is posted here.

I looked into some answers referring this error, but those don't seem to apply to my problem, since I'm using Spring-Boot, no xml configs whatsoever.

The affected controller is:

    @RequestMapping(value = "/user/{id}", method = RequestMethod.GET)
public ResponseEntity<User> getUser(@PathVariable Long id){
    try{
        return new ResponseEntity<User>(userService.getUserById(id), HttpStatus.OK);
    }catch(NoSuchUserException e){
        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
}

Any help would be greatly appreciated. It is very weird since the exact same things work on other machines perfectly.

solution https://stackoverflow.com/questions/41719142/how-to-return-a-set-of-objects-with-spring-boot/46977580#46977580 — Akshay Vijay Jain, Oct 27 '17 at 14:39

score 33 · Answer 1 · answered Nov 10 '16 at 16:03

33

This happened to me, on one resource only (one method) and I did not understand why. All methods within classes in the same package, with the same annotations, same call to ResponseEntity.ok(...) etc. just worked.

But not this one.

It turns out I had forgottent to generate the getters on my POJO class !

As soon as I had added them it worked.

Hopefully it can save somebody some time eventually...

answered Nov 10 '16 at 16:03

Pierre Henry

16,658
22
85
105

5

This fixed my problem too. If anyone tracking this post is still having issues, check your POJO getter's closely; in my case, I had a lower-cased getter on one property; instead of the expected camel case: gettargetObject() instead of getTargetObject() – Michael M Jun 07 '17 at 17:27
2

Same with me..I had forgotten to add getters in my POJO class. Plus1 – Tushar Thakur Jan 23 '19 at 11:34
2

Works like a charm. with SpringBoot 2.0+, no need to manually add dependency for jackson, no need to register MessageConverter manually, what u need is just getters for ur POJO. – reniaL Mar 13 '19 at 07:45

score 19 · Accepted Answer · answered Nov 24 '15 at 14:22

you should make some changes to your pom.xml and mvc-dispatcher-servlet.xml files: Add the following dependecies to your pom.xml :

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.4.3</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.4.3</version>
</dependency>

and update your mvc-dispatcher-servlet.xml:

<mvc:annotation-driven>
     <mvc:message-converters>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
   </mvc:message-converters>
</mvc:annotation-driven>

FYI, using Spring Boot `1.4.0.RELEASE` all I needed was the dependencies. — cbmeeks, Aug 09 '16 at 20:26

score 9 · Answer 3 · answered Feb 02 '16 at 19:01

9

This happens when you forget the "build" call:

return ResponseEntity.status(HttpStatus.BAD_REQUEST);

should be:

return ResponseEntity.status(HttpStatus.BAD_REQUEST).build();

answered Feb 02 '16 at 19:01

Kaan Yy

471
6
9

score 5 · Answer 4 · answered Aug 29 '18 at 01:08

5

I meet with this problem, because I omitted Getters and Setters method.

answered Aug 29 '18 at 01:08

duyuanchao

3,863
1
25
16

JACH · Answer 5 · 2022-08-25T21:38:12.483

1

To add to the rest of the answers: the methods must be public.

My IDE flagged that the methods could be "package only", prompting me to remove the "public" portion of the declaration (which I foolishly did).

I added public to my methods and solved the problem.

edited Aug 25 '22 at 21:38

answered Feb 18 '21 at 22:41

JACH

996
11
20

score 0 · Answer 6 · answered Aug 06 '19 at 21:34

0

I was using IntelliJ Idea and its auto-generated getters and setters. Since I had a boolean field called success, the getter was named isSucccess(). I renamed it getSuccess() and the error went away.

answered Aug 06 '19 at 21:34

Santiago Martí Olbrich

1,601
19
25

Spring Boot Application: No converter found for return value of type

6 Answers6

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