CODEWITHSUNDEEP
jsonrestjax-rsjacksonresteasy
user1632803
user1632803

Reputation: 321

Unable to find a MessageBodyReader of content-type application/json and type class java.lang.String

I am using RestEasy client with jackson providers and getting the above error

clientside code is: 

ClientRequest request = new ClientRequest(url);
request.accept(MediaType.APPLICATION_JSON);
ClientResponse<String> response = request.get(String.class);

if (response.getStatus() != 200) {
  throw new RuntimeException("Failed : HTTP error code : " + response.getStatus());
}

BufferedReader br =
  new BufferedReader(new InputStreamReader(new ByteArrayInputStream(response.getEntity().getBytes())));

response.getEntity() is throwing ClientResponseFailure exception with the error being

Unable to find a MessageBodyReader of content-type application/json and type class java.lang.String

My server side code is below:

@GET
@Path("/{itemId}")
@Produces(MediaType.APPLICATION_JSON)
public String item(@PathParam("itemId") String itemId) {
  //custom code

  return gson.toJSON(object);
}

Upvotes: 24

Views: 57667

Answers (9)

Andreas Panagiotidis
Andreas Panagiotidis

Reputation: 3002

In my case the problem was IntelliJ IDEA. Using maven the test I have the code was running fine, but not using IntelliJ Run function.

Solution: Closed the IntelliJ project, delete target directory and the idea files. Import project again Run the test and it worked.

Upvotes: 0

Bruno Horta
Bruno Horta

Reputation: 221

Client client = ClientBuilder.newBuilder().register(ResteasyJacksonProvider.class).build();

Upvotes: 5

Dmitry Svn
Dmitry Svn

Reputation: 71

Things that had made work my code were that I added:

<dependency>
    <groupId>org.jboss.resteasy</groupId>
    <artifactId>resteasy-jackson2-provider</artifactId>
    <version>&{resteasy.version}</version>
</dependency>

Beside this I don't know why but it seems that resteasy not initializing providers when client were created, this means that it required to init them manually: 

 ResteasyProviderFactory instance=ResteasyProviderFactory.getInstance();
 RegisterBuiltin.register(instance);
 instance.registerProvider(ResteasyJackson2Provider.class);

In general it's enough to run the client.

Upvotes: 1

JCalcines
JCalcines

Reputation: 1286

I had a similar problem and I realized that the problem was related with the version of resteasy-jackson-provider. I just moved from 3.0.4.Final to 3.0.5.Final and the problem disappeared.

Additionally I also realized that if I change the third line to the following the result was the expected with no need to change the dependencies.

Response response = request.get(Object.class).toString();

Upvotes: 1

MatteoM
MatteoM

Reputation: 235

Just adding the line org.jboss.resteasy.plugins.providers.jackson.ResteasyJacksonProvider into META-INF/services/javax.ws.rs.ext.Providers file, solves the problem.

This file is included into resteasy-jackson-providers.jar but same file is also included into another jar, restasy-jaxrs.jar and for an executable jar file, that use both these jars, they are not merged !!

Upvotes: 2

user1632803
user1632803

Reputation: 321

The problem actually is that RestEasy is unable to find the Jackson provider. I had to manually register it by the following code:

   ResteasyProviderFactory instance=ResteasyProviderFactory.getInstance();
    RegisterBuiltin.register(instance);
    instance.registerProvider(ResteasyJacksonProvider.class);

Everything is working fine with this. But I am still unhappy with the solution as Resteasy is supposed to scan for the providers and register them automatically.

Upvotes: 8

Dog
Dog

Reputation: 611

You could try to add the following dependency to your maven pom.

   <dependency>
    <groupId>org.jboss.resteasy</groupId>
    <artifactId>resteasy-jackson-provider</artifactId>
    <version>2.3.4.Final</version>
   </dependency>

Upvotes: 61

StaxMan
StaxMan

Reputation: 116502

If you really want to by-pass goodness of JAX-RS actually doing serialization for you (instead of manually calling GSON), use StreamingOutput (i.e. wrap outputter as StreamingOutput, return that object).

Upvotes: 0

Pascal G&#233;linas
Pascal G&#233;linas

Reputation: 2824

I don't know the full rationale behind that but we've hit the exact same problem (multiple times :P) and you need to change the MediaType to TEXT_PLAIN.

Or you can also let JAX-RS do the job for you: instead of doing gson.toJSON(object), simply return object and change your method signature to whatever class that is. JAX-RS (RESTEasy in your case) will automatically call Jackson (if it's properly configured) and serialize your object to json. Then on your client side you would request for that same class instead of String and everything should work on its own. I'm not particularly familiar with ClientRequest/Response so it might not work as I said; we use RESTEasy proxy functionality on the client side instead (see ProxyFactory). Nevertheless, JAX-RS/RESTEasy can do json serialize/deserialize automatically on the client side too so there's definetly a way.

Upvotes: 0

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