Package org.apache.log4j
Class MDC
java.lang.Object
org.apache.log4j.MDC
The MDC class is similar to the
NDC
class except that it is based on
a map instead of a stack. It provides mapped diagnostic contexts. A
Mapped Diagnostic Context, or MDC in short, is an instrument for
distinguishing interleaved log output from different sources. Log output is
typically interleaved when a server handles multiple clients
near-simultaneously.
The MDC is managed on a per thread basis. A child thread automatically inherits a copy of the mapped diagnostic context of its parent.
The MDC class requires JDK 1.2 or above. Under JDK 1.1 the MDC will always return empty values but otherwise will not affect or harm your application.
- Since:
- 1.2
- Author:
- Ceki Gülcü
-
Method Summary
Modifier and TypeMethodDescriptionstatic void
clear()
Remove all values from the MDC.static Object
Get the context identified by thekey
parameter.static Hashtable
Get the current thread's MDC as a hashtable.static void
Put a context value (theo
parameter) as identified with thekey
parameter into the current thread's context map.static void
Remove the the context identified by thekey
parameter.
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Method Details
-
put
Put a context value (theo
parameter) as identified with thekey
parameter into the current thread's context map.If the current thread does not have a context map it is created as a side effect.
-
get
Get the context identified by thekey
parameter.This method has no side effects.
-
remove
Remove the the context identified by thekey
parameter. -
getContext
Get the current thread's MDC as a hashtable. This method is intended to be used internally. -
clear
public static void clear()Remove all values from the MDC.- Since:
- 1.2.16
-