org.apache.velocity

Class VelocityContext

public class VelocityContext extends AbstractContext implements Cloneable

General purpose implemention of the application Context interface for general application use. This class should be used in place of the original Context class. This implementation uses a HashMap (@see java.util.HashMap ) for data storage. This context implementation cannot be shared between threads without those threads synchronizing access between them, as the HashMap is not synchronized, nor are some of the fundamentals of AbstractContext. If you need to share a Context between threads with simultaneous access for some reason, please create your own and extend the interface Context

Version: $Id: VelocityContext.java,v 1.6.8.1 2004/03/03 22:27:36 geirm Exp $

Author: Geir Magnusson Jr. Jason van Zyl Fedor Karpelevitch Daniel Rall

See Also:

Field Summary
Mapcontext
Storage for key/value pairs.
Constructor Summary
VelocityContext()
Creates a new instance (with no inner context).
VelocityContext(Map context)
Creates a new instance with the provided storage (and no inner context).
VelocityContext(Context innerContext)
Chaining constructor, used when you want to wrap a context in another.
VelocityContext(Map context, Context innerContext)
Initializes internal storage (never to null), and inner context.
Method Summary
Objectclone()
Clones this context object.
booleaninternalContainsKey(Object key)
determines if there is a value for the given key
ObjectinternalGet(String key)
retrieves value for key from internal storage
Object[]internalGetKeys()
returns array of keys
ObjectinternalPut(String key, Object value)
stores the value for key to internal storage
ObjectinternalRemove(Object key)
remove a key/value pair from the internal storage

Field Detail

context

private Map context
Storage for key/value pairs.

Constructor Detail

VelocityContext

public VelocityContext()
Creates a new instance (with no inner context).

VelocityContext

public VelocityContext(Map context)
Creates a new instance with the provided storage (and no inner context).

VelocityContext

public VelocityContext(Context innerContext)
Chaining constructor, used when you want to wrap a context in another. The inner context will be 'read only' - put() calls to the wrapping context will only effect the outermost context

Parameters: innerContext The Context implementation to wrap.

VelocityContext

public VelocityContext(Map context, Context innerContext)
Initializes internal storage (never to null), and inner context.

Parameters: context Internal storage, or null to create default storage. innerContext Inner context.

Method Detail

clone

public Object clone()
Clones this context object.

Returns: A deep copy of this Context.

internalContainsKey

public boolean internalContainsKey(Object key)
determines if there is a value for the given key

Parameters: key name of value to check

Returns: true if non-null value in store

internalGet

public Object internalGet(String key)
retrieves value for key from internal storage

Parameters: key name of value to get

Returns: value as object

internalGetKeys

public Object[] internalGetKeys()
returns array of keys

Returns: keys as []

internalPut

public Object internalPut(String key, Object value)
stores the value for key to internal storage

Parameters: key name of value to store value value to store

Returns: previous value of key as Object

internalRemove

public Object internalRemove(Object key)
remove a key/value pair from the internal storage

Parameters: key name of value to remove

Returns: value removed

Copyright B) 2002 Apache Software Foundation. All Rights Reserved.