[FIXED] Spring RestTemplate, intercepting response before parsing to Json

Issue

I have a REST api that responds with some additional non JSON data in the body content. This breaks the use of RestTemplate and jackson. Can I intercept the http response body prior to the parsing?

I am using RestTemplate.getForObject.

I've taken a look at the RestTemplate and couldn't see an appropriate method.

Solution

You can try to implement ClientHttpRequestInterceptor and assign it to restTemplate. Implement intercept method:

@Override
public ClientHttpResponse intercept(HttpRequest httpRequest, byte[] bytes,
        ClientHttpRequestExecution clientHttpRequestExecution) throws IOException {

         ClientHttpResponse  response=clientHttpRequestExecution.execute(httpRequest, bytes);
         //...do magic with response body from getBody method
         return response;
}

You might have to extend AbstractClientHttpResponse with your own implementation to do that.

Another option could be to treat the response from the REST API as String, then format the string as needed and explicitly map it to object using ObjectMapper.

Then in your restTemplate you would have:

 String result = restTemplate.getForObject(url, String.class, host);
 //..trim the extra stuff
 MyClass object=objectMapper.readValue(result, MyClass.class);

Yet another option would be to implement your own HttpMessageConverter which extends AbstractJackson2HttpMessageConverter and register it with restTemplate. In my opinion that would be the cleaneast from the Spring point of view

Answered By - jny
Answer Checked By - Mildred Charles (JavaFixing Admin)