Class W3CBaggagePropagator

java.lang.Object
io.opentelemetry.api.baggage.propagation.W3CBaggagePropagator
All Implemented Interfaces:
TextMapPropagator
public final class W3CBaggagePropagator extends Object implements TextMapPropagator
TextMapPropagator that implements the W3C specification for baggage header propagation.

  • Field Details

  • Constructor Details

    • W3CBaggagePropagator

      private W3CBaggagePropagator()

  • Method Details

    • getInstance

      public static W3CBaggagePropagator getInstance()
      Singleton instance of the W3C Baggage Propagator.

    • fields

      public Collection<String> fields()
      Description copied from interface: TextMapPropagator
      The propagation fields defined. If your carrier is reused, you should delete the fields here before calling TextMapPropagator.inject(Context, Object, TextMapSetter) )}.

      For example, if the carrier is a single-use or immutable request object, you don't need to clear fields as they couldn't have been set before. If it is a mutable, retryable object, successive calls should clear these fields first.

      Some use cases for this are:

      • Allow pre-allocation of fields, especially in systems like gRPC Metadata
      • Allow a single-pass over an iterator
      Specified by:
      fields in interface TextMapPropagator
      Returns:
      the fields that will be used by this formatter.

    • inject

      public <C> void inject(Context context, @Nullable C carrier, TextMapSetter<C> setter)
      Description copied from interface: TextMapPropagator
      Injects data for downstream consumers, for example as HTTP headers. The carrier may be null to facilitate calling this method with a lambda for the TextMapSetter, in which case that null will be passed to the TextMapSetter implementation.
      Specified by:
      inject in interface TextMapPropagator
      Type Parameters:
      C - carrier of propagation fields, such as an http request
      Parameters:
      context - the Context containing the value to be injected.
      carrier - holds propagation fields. For example, an outgoing message or http request.
      setter - invoked for each propagation key to add or remove.

    • baggageToString

      private static String baggageToString(Baggage baggage)

    • encodeValue

      private static String encodeValue(String value)

    • extract

      public <C> Context extract(Context context, @Nullable C carrier, TextMapGetter<C> getter)
      Description copied from interface: TextMapPropagator
      Extracts data from upstream. For example, from incoming http headers. The returned Context should contain the extracted data, if any, merged with the data from the passed-in Context.

      If the incoming information could not be parsed, implementations MUST return the original Context, unaltered.

      Specified by:
      extract in interface TextMapPropagator
      Type Parameters:
      C - the type of carrier of the propagation fields, such as an http request.
      Parameters:
      context - the Context used to store the extracted value.
      carrier - holds propagation fields. For example, an outgoing message or http request.
      getter - invoked for each propagation key to get data from the carrier.
      Returns:
      the Context containing the extracted data.

    • extractEntries

      private static void extractEntries(String baggageHeader, BaggageBuilder baggageBuilder)

    • baggageIsInvalid

      private static boolean baggageIsInvalid(String key, BaggageEntry baggageEntry)

    • isValidBaggageKey

      private static boolean isValidBaggageKey(String name)
      Determines whether the given String is a valid entry key.
      Parameters:
      name - the entry key name to be validated.
      Returns:
      whether the name is valid.

    • isValidBaggageValue

      private static boolean isValidBaggageValue(String value)
      Determines whether the given String is a valid entry value.
      Parameters:
      value - the entry value to be validated.
      Returns:
      whether the value is valid.

    • toString

      public String toString()
      Overrides:
      toString in class Object