org.apache.avalon.framework.component
Class DefaultComponentManager

java.lang.Object
  |
  +--org.apache.avalon.framework.component.DefaultComponentManager

All Implemented Interfaces:

ComponentManager

public class DefaultComponentManager

extends java.lang.Object

implements ComponentManager

This class is a static implementation of a ComponentManager. Allow ineritance and extension so you can generate a tree of ComponentManager each defining Component scope.

Author:

Federico Barbieri, Peter Donald

Constructor Summary

DefaultComponentManager()
Construct ComponentManager with no parent.

DefaultComponentManager(ComponentManager parent)
Construct ComponentManager with specified parent.

Method Summary

protected void	checkWriteable()
protected java.util.Map	getComponentMap() Helper method for subclasses to retrieve component map.
protected ComponentManager	getParent() Helper method for subclasses to retrieve parent.
boolean	hasComponent(java.lang.String role) Check to see if a Component exists for a role.
Component	lookup(java.lang.String role) Retrieve Component by role from ComponentManager.
void	makeReadOnly()
void	put(java.lang.String role, Component component) Place Component into ComponentManager.
void	release(Component component) Release component.
java.lang.String	toString() Build a human readable representation of ComponentManager.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultComponentManager

public DefaultComponentManager()

Construct ComponentManager with no parent.

DefaultComponentManager

public DefaultComponentManager(ComponentManager parent)

Construct ComponentManager with specified parent.

Parameters:

parent - the ComponentManagers parent

Method Detail

lookup

public Component lookup(java.lang.String role)
                 throws ComponentException

Retrieve Component by role from ComponentManager.

Specified by:

lookup in interface ComponentManager

Parameters:

role - the role

Returns:

the Component

Throws:

ComponentException - if an error occurs

hasComponent

public boolean hasComponent(java.lang.String role)

Description copied from interface: ComponentManager

Check to see if a Component exists for a role.

Specified by:

hasComponent in interface ComponentManager

Following copied from interface: org.apache.avalon.framework.component.ComponentManager

Parameters:

role - a string identifying the role to check.

Returns:

True if the component exists, False if it does not.

put

public void put(java.lang.String role,
                Component component)

Place Component into ComponentManager.

Parameters:

role - the components role

component - the component

release

public void release(Component component)

Release component.

Specified by:

release in interface ComponentManager

Parameters:

component - the component

toString

public java.lang.String toString()

Build a human readable representation of ComponentManager.

Overrides:

toString in class java.lang.Object

Returns:

the description of ComponentManager

getParent

protected final ComponentManager getParent()

Helper method for subclasses to retrieve parent.

Returns:

the parent ComponentManager

getComponentMap

protected final java.util.Map getComponentMap()

Helper method for subclasses to retrieve component map.

Returns:

the component map

makeReadOnly

public void makeReadOnly()

checkWriteable

protected final void checkWriteable()
                             throws java.lang.IllegalStateException