Package org.zalando.logbook

Interface Strategy

@API(status=STABLE)
public interface Strategy

A strategy is glue between Logbook integrations and the Sink. The lifecycle of a request-response pair will invoke methods in the following order:

1. process(HttpRequest)
2. write(Precorrelation, HttpRequest, Sink)
3. process(HttpRequest, HttpResponse)
4. write(Correlation, HttpRequest, HttpResponse, Sink)

At each of those points in time different options are available, e.g. to defer logging, apply conditions or even modify something. Strategy pattern

Method Summary

Modifier and Type	Method	Description
default HttpRequest	process(HttpRequest request)	This method is being called right before the request body is being buffered.
default HttpResponse	process(HttpRequest request, HttpResponse response)	This method is being called right before the response body is being buffered.
default void	write(Correlation correlation, HttpRequest request, HttpResponse response, Sink sink)	This method is being called right after the response body was buffered.
default void	write(Precorrelation precorrelation, HttpRequest request, Sink sink)	This method is being called right after the response body was buffered.

Method Detail

process

default HttpRequest process(HttpRequest request)
                     throws IOException

This method is being called right before the request body is being buffered. The primary goal of this method is to decide whether the body should be recorded or not.

Defaults to HttpRequest.withBody().

Parameters:

request - the current request

Returns:

the given request

Throws:

IOException - see HttpRequest.withBody()

See Also:

HttpRequest.withBody(), HttpRequest.withoutBody()

write

default void write(Precorrelation precorrelation,
                   HttpRequest request,
                   Sink sink)
            throws IOException

This method is being called right after the response body was buffered. The primary goal of this method is to decide whether and if then how the request is being logged.

Options include but are not limited to:

• Log request immediately.
• Defer logging to a later point in time (e.g. when the response becomes available).
• Log request conditionally.
• Log request without body. (Performance penalty for buffering still applies!)

Defaults to delegating to Sink.write(Precorrelation, HttpRequest).

Parameters:

precorrelation - a preliminary correlation which provides an id to correlate request and response later

request - the current request

sink - the sink to write to, if needed

Throws:

IOException - see Sink.write(Precorrelation, HttpRequest)

See Also:

Sink.write(Precorrelation, HttpRequest)

process

default HttpResponse process(HttpRequest request,
                             HttpResponse response)
                      throws IOException

This method is being called right before the response body is being buffered. The primary goal of this method is to decide whether the body should be recorded or not. Beware that the response may or may not be a reliable source of information since it was fully processed yet. Any decision whether to buffer the body or not should be made exclusively based on the provided request.

Defaults to HttpResponse.withBody().

Parameters:

request - the current request

response - the current response

Returns:

the given response

Throws:

IOException - see HttpResponse.withBody()

See Also:

HttpResponse.withBody(), HttpResponse.withoutBody()

write

default void write(Correlation correlation,
                   HttpRequest request,
                   HttpResponse response,
                   Sink sink)
            throws IOException

This method is being called right after the response body was buffered. The primary goal of this method is to decide whether and if then how the response (and optionally also the request) is being logged.

Options include but are not limited to:

• Log response immediately.
• Log response conditionally.
• Log response without body. (Performance penalty for buffering still applies!)
• Log request now, instead of earlier.
• Log request conditionally based on the response.
• Log request without body. (Performance penalty for buffering still applies!)

Defaults to delegating to Sink.write(Correlation, HttpRequest, HttpResponse).

Parameters:

correlation - a correlation which provides and id (as well as a duration) to correlate request and response later

request - the current request

response - the current response

sink - the sink to write to, if needed

Throws:

IOException - see Sink.write(Correlation, HttpRequest, HttpResponse)

See Also:

Sink.write(Correlation, HttpRequest, HttpResponse), Sink.writeBoth(Correlation, HttpRequest, HttpResponse)