Could not read JSON: Unrecognized field (...), not marked as ignorable

Question

Yeah, I know that this issue has been discussed a few times, but I didn't manage to solve my problem.

So I'm getting a JSONObject from a http-request using org.springframework.web.client.RestTemplate:

JSONObject j = RestTemplate.getForObject(url, JSONObject.class);

But I get this error:

 Exception in thread "main" org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Unrecognized field "uri" (Class org.json.JSONObject), not marked as ignorable
 at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@6f526c5f; line: 2, column: 12] (through reference chain: org.json.JSONObject["uri"]); nested exception is org.codehaus.jackson.map.exc.UnrecognizedPropertyException: Unrecognized field "uri" (Class org.json.JSONObject), not marked as ignorable
 at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@6f526c5f; line: 2, column: 12] (through reference chain: org.json.JSONObject["uri"])
 at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.readJavaType(MappingJacksonHttpMessageConverter.java:181)
 at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.read(MappingJacksonHttpMessageConverter.java:173)
 at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:94)
 at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:517)
 at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:472)
 at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:237)

I want to access a Rest-Api and the Json Objects can have different field names. I already tried @JsonIgnoreProperties(ignoreUnknown=true). But this won't work...

How do I get the response into a JSONObject?

Answer 1

You can use this with Jackson 2.0 :

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(
DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

If your version is prior to 2.0 use :

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(
DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);

• Maik: I've read about this, but how exactly do i use the readValue() Method?
• Maik: Ok, nevermind i figured it out, but now i get a Exception in thread "main" org.codehaus.jackson.JsonParseException: Unexpected character ('h' (code 104)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
• Maik: Sorry for so many answers..i'm working on it and got it running. Thanks for now!
• Luis Mauricio: @Maik care to share?

Answer 2

use annotation @JsonIgnoreProperties(ignoreUnknown = true) at class level import from packaage org.codehaus.jackson.annotate.JsonIgnoreProperties