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public class: MDC [javadoc | source]
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.

Field Summary
static final  MDC mdc     
static final  int HT_SIZE     
 boolean java1     
 Object tlm     
Method from org.apache.log4j.MDC Summary:
clear,   get,   getContext,   put,   remove
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.log4j.MDC Detail:
 public static  void clear() 
    Remove all values from the MDC.
 public static Object get(String key) 
    Get the context identified by the key parameter.

    This method has no side effects.

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