Package org.slf4j

Class MDCAmbit

java.lang.Object

org.slf4j.MDCAmbit

public class MDCAmbit
extends Object

This class assists in the creation and removal (aka closing) of MDC entries.

Typical Usage example:

  MDCAmbit mdca = new MDCAmbit();
  try {
    mdca.put("k0", "v0");
    doSomething();
  } catch (RuntimeException e) {
    // here MDC.get("k0") would return "v0"
  } finally {
    // MDC remove "k0"
    mdca.clear();
  }
 

It is also possible to chain put(java.lang.String, java.lang.String), addKeys(String...) and addKey(String) invocations.

For example:

   MDCAmbit mdca = new MDCAmbit();
   try {
     // assume "k0" was added to MDC at an earlier stage
     mdca.addKey("k0").put("k1", "v1").put("k2, "v2");
     doSomething();
   } finally {
     // MDC remove "k0", "k1", "k2", clear the set of tracked keys
     mdch.clear();
   }
 

The run(Runnable) and call(Callable) methods invoke the run/callable methods of objects passed as parameter in a try/finally block, and afterwards invoking clear() method from within finally.

    DCAmbit mdca = new MDCAmbit();
    Runnable runnable = ...;
    mdca.put("k0", "v0").run(runnable);
 

Since:

2.1.0

Constructor Summary

Constructors

Constructor	Description
MDCAmbit()

Method Summary

Modifier and Type	Method	Description
MDCAmbit	addKey(String key)	Keep track of a key for later removal by a call to clear().
MDCAmbit	addKeys(String... keys)	Keep track of several keys for later removal by a call to clear() .
<T> T	call(Callable<? extends T> callable)	Invoke the Callable.call() method of the callable object passed as parameter within a try/finally block.
void	clear()	Clear tracked keys by calling MDC.remove(java.lang.String) on each key.
MDCAmbit	put(String key, String value)	Put the key/value couple in the MDC and keep track of the key for later removal by a call to clear() }.
void	run(Runnable runnable)	Run the runnable object passed as parameter within a try/finally block.

Methods inherited from class java.lang.Object

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

Constructor Details

MDCAmbit

public MDCAmbit()

Method Details

put

public MDCAmbit put(String key,
 String value)

Put the key/value couple in the MDC and keep track of the key for later removal by a call to clear() }.

Parameters:

key -

value -

Returns:

this instance

addKey

public MDCAmbit addKey(String key)

Keep track of a key for later removal by a call to clear(). .

Parameters:

key -

Returns:

this instance

addKeys

public MDCAmbit addKeys(String... keys)

Keep track of several keys for later removal by a call to clear() .

Parameters:

keys -

Returns:

this instance

run

public void run(Runnable runnable)

Run the runnable object passed as parameter within a try/finally block.

Afterwards, the clear() method will be called within the `finally` block.

Parameters:

runnable -

call

public <T> T call(Callable<? extends T> callable)
           throws Exception

Invoke the Callable.call() method of the callable object passed as parameter within a try/finally block.

Afterwards, the clear() method will be invoked within the `finally` block.

Parameters:

callable -

Throws:

Exception

clear

public void clear()

Clear tracked keys by calling MDC.remove(java.lang.String) on each key.

In addition, the set of tracked keys is cleared.

This method is usually called from within finally statement of a try/catch/finally block