Get size of serialized Request using Spring RestTemplate

Question

I am using Spring and RestTemplate to send requests to a REST service. Is there a way to get the (byte)size of the actual request? Optimally it includes the size of the HTTP request including the size of the serialized myObject object for both GET and POST requests.

template.postForObject(restUrl, myObject, MyObject.class);
template.getForObject(restUrl, MyObject.class);

Basically I want to know how much data is actually transmitted.

Thanks!

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[edit]:

Just to complete the answer, this is how you add the Interceptor to the RestTemplate. I also edited the LengthInterceptor to show the content length of the request instead of the response.

final List<ClientHttpRequestInterceptor> interceptors = new ArrayList<ClientHttpRequestInterceptor>();
interceptors.add( new LengthInterceptor() );
template.setInterceptors( interceptors );

Answer 1

You can use interceptor to intercept the request/response similarly to filter in java servlet. You have to read the response and using getHeaders().getContentLength() you'll get the body length:

public class LengthInterceptor implements ClientHttpRequestInterceptor {
    @Override
    public ClientHttpResponse intercept( HttpRequest request, byte[] body, ClientHttpRequestExecution execution ) throws IOException {

        ClientHttpResponse response = execution.execute( request, body );
        long length = response.getHeaders().getContentLength();
        // do something with length
        return response;
    }
}