This annoyed me! Expected a string but was BEGIN_OBJECT at line 1 column 2.

[biniama]

Error 2015-07-09 13:30:22,849 [http-bio-8080-exec-4] ERROR errors.GrailsExceptionResolver - IllegalStateException occurred when processing request: [GET] /recipes-mashup/bigOven/batch
Expected a string but was BEGIN_OBJECT at line 1 column 2. Stacktrace follows:
Message: Expected a string but was BEGIN_OBJECT at line 1 column 2
Line | Method
->> 821 | nextString in com.google.gson.stream.JsonReader

---

| 358 | read in com.google.gson.internal.bind.TypeAdapters$13
| 346 | read . . . . . . . in ''
| 803 | fromJson in com.google.gson.Gson
| 768 | fromJson . . . . . in ''
| 312 | invokeRestTemplate in grails.plugins.rest.client.RestBuilder
| 273 | doRequestInternal in ''
| 261 | doRequestInternal in ''
| 106 | get . . . . . . . in ''
| 29 | getBatch in com.bonial.hackathon.services.BigOvenService
| 16 | batch . . . . . . in com.bonial.hackathon.BigOvenController
| 198 | doFilter in grails.plugin.cache.web.filter.PageFragmentCachingFilter
| 63 | doFilter . . . . . in grails.plugin.cache.web.filter.AbstractFilter
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
| 615 | run . . . . . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^ 745 | run in java.lang.Thread

[graemerocher]

Great that it annoyed you, but please provide more information than this, we cannot possibly reproduce if you just paste a stack trace

[biniama]

This is the code I tried it with.

    String api_key = "123"

    RestBuilder rest = new RestBuilder()

    def resp = rest.get('http://api.bigoven.com/recipes?pg=1&rpp=9&title_kw=cake&api_key=$api_key')   {
        accept 'application/json'
        contentType 'application/json'
    }

    render resp.json

I found a workaround,
/** WORKAROUND
*
* error:
* "org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: java.lang.IllegalStateException: Expected a string but was BEGIN_OBJECT at line 1 column 2;
*
* found from: https://jira.grails.org/browse/GPREST-13
* */
rest.restTemplate.messageConverters.removeAll {
it.class.name == 'org.springframework.http.converter.json.GsonHttpMessageConverter'
}

But, I still need a solution.

Plus, the returned value's content type is not 'application/json' rather 'text/html;charset=utf-8'

[pablovilas]

I've the same problem, any idea?

[pablovilas]

Well, looking at the code I've found a solution

def resp = rest.get('http://api.bigoven.com/recipes?pg=1&rpp=9&title_kw=cake&api_key=$api_key') {
contentType 'application/json'
accept JsonObject
}

You must replace 'application/json' with JsonObject, I think that both ways should be supported.
Good luck

[matthijsbierman]

For the old behaviour, which will parse it into a org.codehaus.groovy.grails.web.json.JSONObject use:

import org.codehaus.groovy.grails.web.json.JSONObject
...
rest.post(url) {
    accept JSONObject, 'application/json'
}

[bobbywarner]

This works just fine for me:

accept("application/json")

So, not sure how to replicate. Can you please post a sample app that demonstrates the problem?

[matthijsbierman]

Sure. The problem may be related to the fact that I'm unit testing with MockRestServiceServer. If you create a new app with Grails 2.5.1:

grails create-app app

And then overwrite/add these files: https://dl.dropboxusercontent.com/u/55056243/example.tar.gz. Update dependencies.

In TestService you can toggle between the two accept statements. Using accept 'application/json' will fail.

[bkoehm]

I believe I have fixed this with the information contained in:
#44

[biniama]

@matthijsbierman 's solution worked. I am closing the issue.

[matthijsbierman]

Glad that it helped, but I don't believe you should have closed the issue already. There is still a problem, because it should work out of the box. It should only be closed once the bug is fixed upstream, as @bkoehm mentioned.

[biniama]

I am re-openning. I spent time trying to cast the output to JSON and perform operations on the JSON but with out success.

[graemerocher]

Use the new version of the underlying JAR to solve the problem:

 compile 'org.grails:grails-datastore-rest-client:5.0.0.RC2'