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.
Put a context value (the
o
parameter) as identified
with the
key
parameter into the current thread's
context map.
static void
remove
(
String
key)
Remove the the context identified by the
key
parameter.
Put a context value (the
o
parameter) as identified
with the
key
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.
public static
Hashtable
getContext
()
Get the current thread's MDC as a hashtable. This method is
intended to be used internally.
