Package io.opentelemetry.api.incubator.propagation

Class EnvironmentGetter

java.lang.Object
io.opentelemetry.api.incubator.propagation.EnvironmentGetter
All Implemented Interfaces:
io.opentelemetry.context.propagation.TextMapGetter<Map<String,String>>
public final class EnvironmentGetter extends Object implements io.opentelemetry.context.propagation.TextMapGetter<Map<String,String>>
A TextMapGetter that extracts context from a map carrier containing environment variables.

This is useful when a child process extracts propagated context from environment variables that an application placed in the child process environment. For example: 


 Map<String, String> env = System.getenv();
 Context context = contextPropagators.getTextMapPropagator()
     .extract(Context.current(), env, EnvironmentGetter.getInstance());

This getter automatically normalizes keys as environment variable names:

  • Replaces an empty key with a single underscore (_)
  • Converts ASCII letters to uppercase (e.g., traceparent becomes TRACEPARENT)
  • Replaces every character that is not an ASCII letter, digit, or underscore with an underscore
  • Prepends an underscore if the result would otherwise start with an ASCII digit

Values are treated as opaque strings. Any propagation-format-specific validation or parsing is the responsibility of the propagator, not this carrier.

If the underlying carrier performs case-insensitive lookup, as Windows environment variable lookup does, reading a normalized key may resolve an entry whose stored name differs only by case.

See Also: