io.opencensus.trace

Class Tracestate

java.lang.Object

io.opencensus.trace.Tracestate

@Immutable
 @ExperimentalApi
public abstract class Tracestate
extends Object

Carries tracing-system specific context in a list of key-value pairs. TraceState allows different vendors propagate additional information and inter-operate with their legacy Id formats.

Implementation is optimized for a small list of key-value pairs.

Key is opaque string up to 256 characters printable. It MUST begin with a lowercase letter, and can only contain lowercase letters a-z, digits 0-9, underscores _, dashes -, asterisks *, and forward slashes /.

Value is opaque string up to 256 characters printable ASCII RFC0020 characters (i.e., the range 0x20 to 0x7E) except comma , and =.

Since:

0.16

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Tracestate.Builder Builder class for MessageEvent.
static class	Tracestate.Entry Immutable key-value pair for Tracestate.

Method Summary

Modifier and Type	Method and Description
static Tracestate.Builder	builder() Returns a Builder based on an empty Tracestate.
String	get(String key) Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
abstract List<Tracestate.Entry>	getEntries() Returns a List view of the mappings contained in this TraceState.
Tracestate.Builder	toBuilder() Returns a Builder based on this Tracestate.

Methods inherited from class java.lang.Object

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

Method Detail

get

@Nullable
public String get(String key)

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

Parameters:

key - with which the specified value is to be associated

Returns:

the value to which the specified key is mapped, or null if this map contains no mapping for the key.

Since:

0.16

getEntries

public abstract List<Tracestate.Entry> getEntries()

Returns a List view of the mappings contained in this TraceState.

Returns:

a List view of the mappings contained in this TraceState.

Since:

0.16

builder

public static Tracestate.Builder builder()

Returns a Builder based on an empty Tracestate.

Returns:

a Builder based on an empty Tracestate.

Since:

0.16

toBuilder

public Tracestate.Builder toBuilder()

Returns a Builder based on this Tracestate.

Returns:

a Builder based on this Tracestate.

Since:

0.16