io.jaegertracing.propagation

Interface Extractor<T>

All Known Subinterfaces:

Codec<T>

All Known Implementing Classes:

B3TextMapCodec, CompositeCodec, TextMapCodec

public interface Extractor<T>

You should implement this class if you want to add possibility to extract information about SpanContext that is provided in your custom propagation scheme. Otherwise you should probably use built-in TextMapCodec or B3TextMapCodec

See Also:

B3TextMapCodec, TextMapCodec, Codec

Method Summary

Modifier and Type	Method and Description
SpanContext	extract(T carrier) Called when Tracer.extract(...) is used.

Method Detail

extract

SpanContext extract(T carrier)

Called when Tracer.extract(...) is used. It should handle the logic behind extracting propagation-scheme specific information from carrier (e.g. http request headers, amqp message headers, etc.).

This method must not modify the carrier

All exceptions thrown from this method will be caught and logged on WARN level so that business code execution isn't affected. If possible, catch implementation specific exceptions and log more meaningful information.

Parameters:

carrier - input that you extract Span information from, usually TextMap.

Returns:

SpanContext or null if carrier doesn't contain tracing information, it is not valid or is incomplete

See Also:

B3TextMapCodec, TextMapCodec