Package io.opentelemetry.api.baggage.propagation

Class W3CBaggagePropagator

java.lang.Object

io.opentelemetry.api.baggage.propagation.W3CBaggagePropagator

All Implemented Interfaces:

TextMapPropagator

public final class W3CBaggagePropagator
extends java.lang.Object
implements TextMapPropagator

TextMapPropagator that implements the W3C specification for baggage header propagation.

Field Summary

Fields

Modifier and Type	Field	Description
private static java.lang.String	FIELD
private static java.util.List<java.lang.String>	FIELDS
private static W3CBaggagePropagator	INSTANCE
private static PercentEscaper	URL_ESCAPER

Constructor Summary

Constructors

Modifier	Constructor	Description
private	W3CBaggagePropagator()

Method Summary

Modifier and Type	Method	Description
private static boolean	baggageIsInvalid(java.lang.String key, BaggageEntry baggageEntry)
private static java.lang.String	baggageToString(Baggage baggage)
private static java.lang.String	encodeValue(java.lang.String value)
<C> Context	extract(Context context, C carrier, TextMapGetter<C> getter)	Extracts data from upstream.
private static void	extractEntries(java.lang.String baggageHeader, BaggageBuilder baggageBuilder)
java.util.Collection<java.lang.String>	fields()	The propagation fields defined.
static W3CBaggagePropagator	getInstance()	Singleton instance of the W3C Baggage Propagator.
<C> void	inject(Context context, C carrier, TextMapSetter<C> setter)	Injects data for downstream consumers, for example as HTTP headers.
private static boolean	isValidBaggageKey(java.lang.String name)	Determines whether the given String is a valid entry key.
private static boolean	isValidBaggageValue(java.lang.String value)	Determines whether the given String is a valid entry value.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

FIELD

private static final java.lang.String FIELD

See Also:

Constant Field Values

FIELDS

private static final java.util.List<java.lang.String> FIELDS

INSTANCE

private static final W3CBaggagePropagator INSTANCE

URL_ESCAPER

private static final PercentEscaper URL_ESCAPER

Constructor Detail

W3CBaggagePropagator

private W3CBaggagePropagator()

Method Detail

getInstance

public static W3CBaggagePropagator getInstance()

Singleton instance of the W3C Baggage Propagator.

fields

public java.util.Collection<java.lang.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 java.lang.String baggageToString(Baggage baggage)

encodeValue

private static java.lang.String encodeValue(java.lang.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(java.lang.String baggageHeader,
                                   BaggageBuilder baggageBuilder)

baggageIsInvalid

private static boolean baggageIsInvalid(java.lang.String key,
                                        BaggageEntry baggageEntry)

isValidBaggageKey

private static boolean isValidBaggageKey(java.lang.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(java.lang.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 java.lang.String toString()

Overrides:

toString in class java.lang.Object