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

Issue

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

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>

Answered By - Yahia Ammar
Answer Checked By - Marie Seifert (JavaFixing Admin)