org.apache.logging.log4j.spi

Interface ReadOnlyThreadContextMap

public interface ReadOnlyThreadContextMap

Read-only view of the data structure that implements MDC behavior for ThreadContext.

ThreadContextMap implementations that also implement this interface can be accessed by applications via the ThreadContext.getThreadContextMap() method.

Since:

2.8

See Also:

ThreadContext.getThreadContextMap()

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the context.
boolean	containsKey(String key) Determines if the key is in the context.
String	get(String key) Gets the context identified by the key parameter.
Map<String,String>	getCopy() Gets a non-null mutable copy of current thread's context Map.
Map<String,String>	getImmutableMapOrNull() Returns an immutable view on the context Map or null if the context map is empty.
StringMap	getReadOnlyContextData() Returns the context data for reading.
boolean	isEmpty() Returns true if the Map is empty.

Method Detail

clear

void clear()

Clears the context.

containsKey

boolean containsKey(String key)

Determines if the key is in the context.

Parameters:

key - The key to locate.

Returns:

True if the key is in the context, false otherwise.

get

String get(String key)

Gets the context identified by the key parameter.

This method has no side effects.

Parameters:

key - The key to locate.

Returns:

The value associated with the key or null.

getCopy

Map<String,String> getCopy()

Gets a non-null mutable copy of current thread's context Map.

Returns:

a mutable copy of the context.

getImmutableMapOrNull

Map<String,String> getImmutableMapOrNull()

Returns an immutable view on the context Map or null if the context map is empty.

Returns:

an immutable context Map or null.

getReadOnlyContextData

StringMap getReadOnlyContextData()

Returns the context data for reading. Note that regardless of whether the returned context data has been frozen (made read-only) or not, callers should not attempt to modify the returned data structure.

Thread safety note:

If this ReadOnlyThreadContextMap implements CopyOnWrite, then the returned StringMap can safely be passed to another thread: future changes in the underlying context data will not be reflected in the returned StringMap.

Otherwise, if this ReadOnlyThreadContextMap does not implement CopyOnWrite, then it is not safe to pass the returned StringMap to another thread because changes in the underlying context may be reflected in the returned object. It is the responsibility of the caller to make a copy to pass to another thread.

Returns:

a StringMap containing context data key-value pairs

isEmpty

boolean isEmpty()

Returns true if the Map is empty.

Returns:

true if the Map is empty, false otherwise.