[java] "Could not find acceptable representation" using spring-boot-starter-web

I am trying to use spring-boot-starter-web to create a rest service serving up JSON representations of Java objects. From what I understand this boot-starter-web jar is supposed to handle the conversion to JSON through Jackson automatically but I am instead getting this error.

{ 
  "timestamp": 1423693929568,
  "status": 406,
  "error": "Not Acceptable",
  "exception": "org.springframework.web.HttpMediaTypeNotAcceptableException",
  "message": "Could not find acceptable representation"
}

My Controller is this...

@RestController
@RequestMapping(value = "/media")
public class MediaController {
    @RequestMapping(value = "/test", method = RequestMethod.POST)
    public @ResponseBody UploadResult test(@RequestParam(value="data") final String data) {
      String value = "hello, test with data [" + data + "]"; 
      return new UploadResult(value);
    }

    @RequestMapping(value = "/test2", method = RequestMethod.POST)
    public int test2() {
        return 42;
    }

    @RequestMapping(value = "/test3", method = RequestMethod.POST)
    public String test3(@RequestParam(value="data") final String data) {
        String value = "hello, test with data [" + data + "]"; 
        UploadResult upload = new UploadResult(value);
        return upload.value;
    }


    public static class UploadResult {
        private String value;
        public UploadResult(final String value)
        {
            this.value = value;
        }
    }
}

My pom.xml has...

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <version>1.2.1.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <version>1.2.1.RELEASE</version>
    <scope>provided</scope>
</dependency>

mvn dependency:tree shows that spring-boot-starter-web does indeed depend on the jackson2.4 databind and thus should be on the classpath...

[INFO] +- org.springframework.boot:spring-boot-starter-web:jar:1.2.1.RELEASE:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter:jar:1.2.1.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot:jar:1.2.1.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-autoconfigure:jar:1.2.1.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-starter-logging:jar:1.2.1.RELEASE:compile
[INFO] |  |  |  +- org.slf4j:jul-to-slf4j:jar:1.7.8:compile
[INFO] |  |  |  \- org.slf4j:log4j-over-slf4j:jar:1.7.8:compile
[INFO] |  |  \- org.yaml:snakeyaml:jar:1.14:runtime
[INFO] |  +- com.fasterxml.jackson.core:jackson-databind:jar:2.4.4:compile
[INFO] |  |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.4.0:compile
[INFO] |  |  \- com.fasterxml.jackson.core:jackson-core:jar:2.4.4:compile
[INFO] |  +- org.hibernate:hibernate-validator:jar:5.1.3.Final:compile
[INFO] |  |  +- javax.validation:validation-api:jar:1.1.0.Final:compile
[INFO] |  |  +- org.jboss.logging:jboss-logging:jar:3.1.3.GA:compile
[INFO] |  |  \- com.fasterxml:classmate:jar:1.0.0:compile
[INFO] |  +- org.springframework:spring-web:jar:4.1.4.RELEASE:compile
[INFO] |  |  +- org.springframework:spring-aop:jar:4.1.4.RELEASE:compile
[INFO] |  |  |  \- aopalliance:aopalliance:jar:1.0:compile
[INFO] |  |  +- org.springframework:spring-beans:jar:4.1.4.RELEASE:compile
[INFO] |  |  \- org.springframework:spring-context:jar:4.1.4.RELEASE:compile
[INFO] |  \- org.springframework:spring-webmvc:jar:4.1.4.RELEASE:compile
[INFO] |     \- org.springframework:spring-expression:jar:4.1.4.RELEASE:compile

... yet calling the test service gives the error mentioned above. test2 and test3 work fine proving that it must just be the attempted conversion to JSON that is failing? Am I missing some configuration problem or annotations? From all the examples I can find, annotating the class for basic Jackson JSON conversion is no longer necessary.

Any help greatly appreciated.

Had similar issue when one of my controllers was intercepting all requests with empty @GetMapping

Add below dependency to your pom.xml:

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <version>2.10.2</version>
</dependency>

My return object didn't have @XmlRootElement annotation on the class. Adding the annotation solved my issue.

@XmlRootElement(name = "ReturnObjectClass")
public class ReturnObjectClass {

    @XmlElement(name = "Status", required = true)
    protected StatusType status;
    //...
}

accepted answer is not right with Spring 5. try changing your URL of your web service to .json! that is the right fix. great details here http://stick2code.blogspot.com/2014/03/solved-orgspringframeworkwebhttpmediaty.html

I was running into the same issue, and what I was missing in my setup was including this in my maven (pom.xml) file.

<dependency>
     <groupId>org.codehaus.jackson</groupId>
     <artifactId>jackson-mapper-asl</artifactId>
     <version>1.9.9</version>
</dependency> 

If you are using Lombok, make sure it have annotations like @Data or @Getter @Setter in your Response Model class.

I had this issue when accessing actuator. Putting following configuration class solved the issue:

@Configuration
@EnableWebMvc
public class MediaConverterConfiguration implements WebMvcConfigurer {
    @Bean
    public MappingJackson2HttpMessageConverter jacksonConverter() {
        MappingJackson2HttpMessageConverter mc =
                new MappingJackson2HttpMessageConverter();
        List<MediaType> supportedMediaTypes =
                new ArrayList<>(mc.getSupportedMediaTypes());
        supportedMediaTypes
                .add(MediaType.valueOf(MediaType.APPLICATION_JSON_VALUE));
        supportedMediaTypes.add(
            MediaType.valueOf("application/vnd.spring-boot.actuator.v2+json"));
        mc.setSupportedMediaTypes(supportedMediaTypes);
        return mc;
    }

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        converters.add(jacksonConverter());
    }
}

For me, the problem was trying to pass a filename in a url, with a dot. For example

"http://localhost:8080/something/asdf.jpg" //causes error because of '.jpg'

It could be solved by not passing the .jpg extension, or sending it all in a request body.

In my case I happened to be using lombok and apparently there are conflicts with the get and set

I had a similar error using spring/jhipster RESTful service (via Postman)

The endpoint was something like:

@RequestMapping(value = "/index-entries/{id}",
        method = RequestMethod.GET,
        produces = MediaType.APPLICATION_JSON_VALUE)
@Timed
public ResponseEntity<IndexEntry> getIndexEntry(@PathVariable Long id) {

I was attempting to call the restful endpoint via Postman with header Accept: text/plain but I needed to use Accept: application/json

I had to explicitly call out the dependency for my json library in my POM.

Once I added the below dependency, it all worked.

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
</dependency>

I too was facing a similar issue. In my case the request path was accepting mail id as path variable, so the uri looked like /some/api/[email protected]

And based on path, Spring determined the uri is to fetch some file with ".com" extension and was trying to use different media type for response then intended one. After making path variable into request param it worked for me.

I had the same exception but the cause was different and I couldn't find any info on that so I will post it here. It was just a simple to overlook mistake.

Bad:

@RestController(value = "/api/connection")

Good:

@RestController
@RequestMapping(value = "/api/connection")

I had the same exception. The problem was, that I used the annotation

@RepositoryRestController

instead of

@RestController

I got the exact same problem. After viewing this reference: http://zetcode.com/springboot/requestparam/

My problem solved by changing

method = RequestMethod.GET, produces = "application/json;charset=UTF-8"

to

method = RequestMethod.GET, produces = MediaType.TEXT_PLAIN_VALUE

and don't forget to add the library:

import org.springframework.http.MediaType;

it works on both postman or regular browser.

If using @FeignClient, add e.g.

produces = "application/json"

to the @RequestMapping annotation

In my case I was sending in correct object in ResponseEntity<>().

Correct :

@PostMapping(value = "/get-customer-details", produces = { MediaType.APPLICATION_JSON_VALUE })
public ResponseEntity<?> getCustomerDetails(@RequestBody String requestMessage) throws JSONException {
    JSONObject jsonObject = new JSONObject();
    jsonObject.put("customerId", "123");
    jsonObject.put("mobileNumber", "XXX-XXX-XXXX");
    return new ResponseEntity<>(jsonObject.toString(), HttpStatus.OK);
}

Incorrect :

return new ResponseEntity<>(jsonObject, HttpStatus.OK);

Because, jsonObject's toString() method "Encodes the jsonObject as a compact JSON string". Therefore, Spring returns json string directly without any further serialization.

When we send jsonObject instead, Spring tries to serialize it based on produces method used in RequestMapping and fails due to it "Could not find acceptable representation".