Class HttpClientHandler<Q,P,C>

java.lang.Object

io.opencensus.contrib.http.AbstractHttpHandler<Q,P>

io.opencensus.contrib.http.HttpClientHandler<Q,P,C>

Type Parameters:

Q - the HTTP request entity.

P - the HTTP response entity.

C - the type of the carrier.

@ExperimentalApi
public class HttpClientHandler<Q,P,C>
extends AbstractHttpHandler<Q,P>

This helper class provides routine methods to instrument HTTP clients.

Since:

0.19

Field Summary

Fields

Modifier and Type	Field	Description
private final TextFormat.Setter<C>	setter
private final StatsRecorder	statsRecorder
private final Tagger	tagger
private final TextFormat	textFormat
private final Tracer	tracer

Fields inherited from class AbstractHttpHandler

extractor

Constructor Summary

Constructors

Constructor	Description
HttpClientHandler(Tracer tracer, HttpExtractor<Q,P> extractor, TextFormat textFormat, TextFormat.Setter<C> setter)	Creates a HttpClientHandler with given parameters.

Method Summary

Modifier and Type	Method	Description
void	handleEnd(HttpRequestContext context, Q request, P response, Throwable error)	Close an HTTP span and records stats specific to the request.
HttpRequestContext	handleStart(Span parent, C carrier, Q request)	Instrument a request for tracing and stats before it is sent.
private void	recordStats(HttpRequestContext context, Q request, int httpCode)

Methods inherited from class AbstractHttpHandler

addSpanRequestAttributes, getNewContext, getSpanFromContext, getSpanName, handleMessageReceived, handleMessageSent, recordMessageEvent, spanEnd

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

setter

private final TextFormat.Setter<C> setter

textFormat

private final TextFormat textFormat

tracer

private final Tracer tracer

statsRecorder

private final StatsRecorder statsRecorder

tagger

private final Tagger tagger

Constructor Details

HttpClientHandler

public HttpClientHandler(Tracer tracer,
 HttpExtractor<Q,P> extractor,
 TextFormat textFormat,
 TextFormat.Setter<C> setter)

Creates a HttpClientHandler with given parameters.

Parameters:

tracer - the Open Census tracing component.

extractor - the HttpExtractor used to extract information from the request/response.

textFormat - the TextFormat used in HTTP propagation.

setter - the setter used when injecting information to the carrier.

Since:

0.19

Method Details

handleStart

public HttpRequestContext handleStart(@Nullable
 Span parent,
 C carrier,
 Q request)

Instrument a request for tracing and stats before it is sent.

This method will create a span in current context to represent the HTTP call. The created span will be serialized and propagated to the server.

The generated span will NOT be set as current context. User can control when to enter the scope of this span. Use AbstractHttpHandler.getSpanFromContext(HttpRequestContext) to retrieve the span.

Parameters:

parent - the parent Span. null indicates using current span.

carrier - the entity that holds the HTTP information.

request - the request entity.

Returns:

the HttpRequestContext that contains stats and trace data associated with the request.

Since:

0.19

handleEnd

public void handleEnd(HttpRequestContext context,
 @Nullable
 Q request,
 @Nullable
 P response,
 @Nullable
 Throwable error)

Close an HTTP span and records stats specific to the request.

This method will set status of the span and end it. Additionally it will record measurements associated with the request.

Parameters:

context - the HttpRequestContext returned from handleStart(Span, Object, Object)

request - the HTTP request entity.

response - the HTTP response entity. null means invalid response.

error - the error occurs when processing the response.

Since:

0.19

recordStats

private void recordStats(HttpRequestContext context,
 @Nullable
 Q request,
 int httpCode)