Package brave.http

Class HttpClientHandler<Req,​Resp>

  • Type Parameters:
    Req - the native http request type of the client.
    Resp - the native http response type of the client.
    public final class HttpClientHandler<Req,​Resp>
extends Object
    This standardizes a way to instrument http clients, particularly in a way that encourages use of portable customizations via HttpRequestParser and HttpResponseParser.

    Synchronous interception is the most straight forward instrumentation.

    You generally need to:

    1. Start the span and add trace headers to the request
    2. Put the span in scope so things like log integration works
    3. Invoke the request
    4. If there was a Throwable, add it to the span
    5. Complete the span
    
 HttpClientRequestWrapper requestWrapper = new HttpClientRequestWrapper(request);
 Span span = handler.handleSend(requestWrapper); // 1.
 HttpClientResponse response = null;
 Throwable error = null;
 try (Scope ws = currentTraceContext.newScope(span.context())) { // 2.
   return response = invoke(request); // 3.
 } catch (Throwable e) {
   error = e; // 4.
   throw e;
 } finally {
   HttpClientResponseWrapper responseWrapper =
     new HttpClientResponseWrapper(requestWrapper, response, error);
   handler.handleReceive(responseWrapper, span); // 5.
 }
    Since:
    4.3