RestTemplate and acessing json

Question

I have seen the responses from many other posts but would like to understand if there is a better way to do the same thing.

Requirement:- I am using restTemplate to talk to web service which returns JSON output which is dynamic. As a consumer I don't want to access all fields but is interested in few of them. I am using Spring framework with Jackson parser and found the way of accessing it

     String  response = restTemplate.getForObject(targetUrl, String.class);
     System.out.println(response);
     ObjectMapper mapper = new ObjectMapper();
     JsonNode rootNode = mapper.readValue(response, JsonNode.class);
     JsonNode uri = rootNode.get("uri");
     System.out.println(uri.asText());

Do you know any better way to do it? Mapping to java Object is something that I dont want to do as the json output is not in my control

Your approach looks good. Note that just do restTemplate.getForObject(targetUrl, JsonNode.class) assuming that your restTemplate is configured to work with Jackson. — Alexey Gavrilov, Jul 12 '14 at 13:49
"restTemplate is configured to work with Jackson" Can you please clarify this? — Milind, Jul 12 '14 at 22:25
You can set an HttpMessageCoverter for your rest template which will covert JSON to java objects. Take a look at the example code this question: http://stackoverflow.com/questions/21355450/spring-resttemplate-with-jackson-as-httpmessageconverter-and-joda-datetime-prope — Alexey Gavrilov, Jul 12 '14 at 22:39
Isnt that is there when you create RestTemplate Object?. I saw it has list of converters already set — Milind, Jul 14 '14 at 14:24
Using `ObjectMapper` is redundant here. As Alexey said you can just use `com.fasterxml.jackson.databind.JsonNode` as the second argument for the `restTemplate.getForObject()` method. — androberz, Dec 23 '15 at 19:39

score 5 · Answer 1 · answered Jun 07 '17 at 14:13

If your RestTemplate is configured with the default HttpMessageConverters, which is provided by Jackson2ObjectMapperBuilder, you may directly get a JsonNode from restTemplate.getForObject.

For example,

ArrayNode resources = restTemplate.getForObject("/resources", ArrayNode.class);

Or,

ObjectNode resource = restTemplate.getForObject("/resources/123", ObjectNode.class);

Note that ArrayNode and ObjectNode are sub-classes of JsonNode.

RestTemplate and acessing json

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