org.codehaus.plexus.context
Class DefaultContext

java.lang.Object
  org.codehaus.plexus.context.DefaultContext

All Implemented Interfaces:

Context

public class DefaultContext
extends java.lang.Object
implements Context

Default implementation of Context. This implementation is a static hierarchial store. It has the normal get() and put methods. The hide method will hide a property. When a property has been hidden the containerContext will not search in the parent containerContext for the value.

Version:

$Id: DefaultContext.java 7797 2008-10-28 17:41:43Z dain $

Author:

Avalon Development Team

Constructor Summary

DefaultContext()
Create an empty Context.

DefaultContext(java.util.Map<java.lang.Object,java.lang.Object> contextData)
Create a Context with specified data.

Method Summary

protected void	checkWriteable() Utility method to check if containerContext is writeable and if not throw exception.
boolean	contains(java.lang.Object key) Returns true if this context contains a value for the specified key.
java.lang.Object	get(java.lang.Object key) Returns the value of the key.
java.util.Map	getContextData() Utility method to retrieve containerContext data
void	hide(java.lang.Object key) Hides the item in the containerContext.
void	makeReadOnly() Make the containerContext read-only.
void	put(java.lang.Object key, java.lang.Object value) Adds the item to the containerContext.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultContext

public DefaultContext()

Create an empty Context.

DefaultContext

public DefaultContext(java.util.Map<java.lang.Object,java.lang.Object> contextData)

Create a Context with specified data. The specified data is copied into the context so any subsequent updates to supplied map are not reflected in this context. Additionally, changes to this context are not reflected in the specified map.

Parameters:

contextData - the containerContext data

Method Detail

contains

public boolean contains(java.lang.Object key)

Description copied from interface: Context

Returns true if this context contains a value for the specified key.

Specified by:

contains in interface Context

Parameters:

key - the key to search

Returns:

true if the key was found; false otherwise

get

public java.lang.Object get(java.lang.Object key)
                     throws ContextException

Description copied from interface: Context

Returns the value of the key. If the key can't be found it will throw a exception.

Specified by:

get in interface Context

Parameters:

key - the key of the value to look up.

Returns:

returns the value associated with the key

Throws:

ContextException - if the key doesn't exist

put

public void put(java.lang.Object key,
                java.lang.Object value)
         throws java.lang.IllegalStateException

Description copied from interface: Context

Adds the item to the containerContext.

Specified by:

put in interface Context

Parameters:

key - the key of the item

value - the item

Throws:

java.lang.IllegalStateException - if this context is read-only

hide

public void hide(java.lang.Object key)
          throws java.lang.IllegalStateException

Description copied from interface: Context

Hides the item in the containerContext. After remove(key) has been called, a get(key) will always fail, even if the parent containerContext has such a mapping.

Specified by:

hide in interface Context

Parameters:

key - the items key

Throws:

java.lang.IllegalStateException - if this context is read-only

getContextData

public java.util.Map getContextData()

Utility method to retrieve containerContext data

Specified by:

getContextData in interface Context

Returns:

the containerContext data

makeReadOnly

public void makeReadOnly()

Make the containerContext read-only. Any attempt to write to the containerContext via put() will result in an IllegalStateException.

Specified by:

makeReadOnly in interface Context

checkWriteable

protected void checkWriteable()
                       throws java.lang.IllegalStateException

Utility method to check if containerContext is writeable and if not throw exception.

Throws:

java.lang.IllegalStateException - if containerContext is read only