org.apache.log

Class ContextMap

java.lang.Object

org.apache.log.ContextMap

All Implemented Interfaces:

Serializable

public final class ContextMap
extends Object
implements Serializable

The ContextMap contains non-hierarchical context information relevant to a particular LogEvent. It may include information such as;

• user ->fred
• hostname ->helm.realityforge.org
• ipaddress ->1.2.3.4
• interface ->127.0.0.1
• caller ??? ???->com.biz.MyCaller.method(MyCaller.java:18)
• source ??? ???->1.6.3.2:33

The context is bound to a thread (and inherited by sub-threads) but it can also be added to by LogTargets.

Author:

Avalon Development Team, Peter Donald

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static ThreadLocal	c_localContext
private Hashtable	m_map
private ContextMap	m_parent
private boolean	m_readOnly

Constructor Summary

Constructors

Constructor and Description
ContextMap() Default constructor.
ContextMap(ContextMap parent) Constructor that sets parent contextMap.

Method Summary

Methods

Modifier and Type	Method and Description
static void	bind(ContextMap context) Bind a particular ContextMap to current thread.
private void	checkReadable() Utility method to verify that Context is read-only.
void	clear() Empty the context map.
Object	get(String key) Get an entry from the context.
Object	get(String key, Object defaultObject) Get an entry from the context.
static ContextMap	getCurrentContext() Get the Current ContextMap.
static ContextMap	getCurrentContext(boolean autocreate) Get the Current ContextMap.
int	getSize() Get the number of contexts in map.
boolean	isReadOnly() Determine if context is read-only.
void	makeReadOnly() Make the context read-only.
private Object	readResolve() Helper method that sets context to read-only after de-serialization.
void	set(String key, Object value) Set a value in context

Methods inherited from class java.lang.Object

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

Field Detail

c_localContext

private static final ThreadLocal c_localContext

m_parent

private final ContextMap m_parent

m_map

private Hashtable m_map

m_readOnly

private transient boolean m_readOnly

Constructor Detail

ContextMap

public ContextMap()

Default constructor.

ContextMap

public ContextMap(ContextMap parent)

Constructor that sets parent contextMap.

Parameters:

parent - the parent ContextMap

Method Detail

getCurrentContext

public static final ContextMap getCurrentContext()

Get the Current ContextMap. This method returns a ContextMap associated with current thread. If the thread doesn't have a ContextMap associated with it then a new ContextMap is created.

Returns:

the current ContextMap

getCurrentContext

public static final ContextMap getCurrentContext(boolean autocreate)

Get the Current ContextMap. This method returns a ContextMap associated with current thread. If the thread doesn't have a ContextMap associated with it and autocreate is true then a new ContextMap is created.

Parameters:

autocreate - true if a ContextMap is to be created if it doesn't exist

Returns:

the current ContextMap

bind

public static final void bind(ContextMap context)

Bind a particular ContextMap to current thread.

Parameters:

context - the context map (may be null)

makeReadOnly

public void makeReadOnly()

Make the context read-only. This makes it safe to allow untrusted code reference to ContextMap.

isReadOnly

public boolean isReadOnly()

Determine if context is read-only.

Returns:

true if Context is read only, false otherwise

clear

public void clear()

Empty the context map.

get

public Object get(String key,
         Object defaultObject)

Get an entry from the context.

Parameters:

key - the key to map

defaultObject - a default object to return if key does not exist

Returns:

the object in context

get

public Object get(String key)

Get an entry from the context.

Parameters:

key - the key to map

Returns:

the object in context or null if none with specified key

set

public void set(String key,
       Object value)

Set a value in context

Parameters:

key - the key

value - the value (may be null)

getSize

public int getSize()

Get the number of contexts in map.

Returns:

the number of contexts in map

readResolve

private Object readResolve()

Helper method that sets context to read-only after de-serialization.

Returns:

the corrected object version

checkReadable

private void checkReadable()

Utility method to verify that Context is read-only.