Package org.apache.avalon.framework.context

Class DefaultContext

java.lang.Object
org.apache.avalon.framework.context.DefaultContext
All Implemented Interfaces:
Context
public class DefaultContext extends Object implements Context
Default implementation of Context. This implementation is a static hierarchial store.
Version:
CVS $Revision: 1.27 $ $Date: 2004/02/11 14:34:26 $
Author:
Avalon Development Team

  • Constructor Details

    • DefaultContext

      public DefaultContext(Map contextData, Context parent)
      Create a Context with specified data and parent.
      Parameters:
      contextData - the context data
      parent - the parent Context (may be null)

    • DefaultContext

      public DefaultContext(Map contextData)
      Create a Context with specified data.
      Parameters:
      contextData - the context data

    • DefaultContext

      public DefaultContext(Context parent)
      Create a Context with specified parent.
      Parameters:
      parent - the parent Context (may be null)

    • DefaultContext

      public DefaultContext()
      Create a Context with no parent.

  • Method Details

    • get

      public Object get(Object key) throws ContextException
      Retrieve an item from the Context.
      Specified by:
      get in interface Context
      Parameters:
      key - the key of item
      Returns:
      the item stored in context
      Throws:
      ContextException - if item not present

    • put

      public void put(Object key, Object value) throws IllegalStateException
      Helper method fo adding items to Context.
      Parameters:
      key - the items key
      value - the item
      Throws:
      IllegalStateException - if context is read only

    • hide

      public void hide(Object key) throws IllegalStateException
      Hides the item in the context. After remove(key) has been called, a get(key) will always fail, even if the parent context has such a mapping.
      Parameters:
      key - the items key
      Throws:
      IllegalStateException - if context is read only

    • getContextData

      protected final Map getContextData()
      Utility method to retrieve context data.
      Returns:
      the context data

    • getParent

      protected final Context getParent()
      Get parent context if any.
      Returns:
      the parent Context (may be null)

    • makeReadOnly

      public void makeReadOnly()
      Make the context read-only. Any attempt to write to the context via put() will result in an IllegalStateException.

    • checkWriteable

      protected final void checkWriteable() throws IllegalStateException
      Utility method to check if context is writeable and if not throw exception.
      Throws:
      IllegalStateException - if context is read only