jfun.yan
Class DecoratingComponent

java.lang.Object
  jfun.yan.Component
      jfun.yan.DelegatingComponent
          jfun.yan.DecoratingComponent

All Implemented Interfaces:

java.io.Serializable, Creator, Stateful, Typeful, Verifiable

public abstract class DecoratingComponent
extends DelegatingComponent

Base class for component decorators that do not change the result returned from the target component it decorates and causes no side-effect by itself other than those caused by the target component.

Some decorator classes of Component may want to forward calls to singleton(), guard(), proxy() to the Component that it delegates and then re-decorate the result.

This class provides the basic facility for this logic. Implement the decorate() method and this class will forward and re-decorate for you.

Use it with caution because it could cause infinite loop if used inappropriately

Codehaus.org.

Author:

Ben Yu

See Also:

Serialized Form

Constructor Summary

DecoratingComponent(Component cc)
Create a new DeleratingComponent object.

Method Summary

protected abstract Component	decorate(Component c) Decorate a Component object.
Component	guard() Decorate this Component so that the new Component object guards against infinite dependency loop.
boolean	isSingleton() Determines if the component always return the same instance and has no side-effect that causes difference when called the second time.
Component	proxy() Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy.
Component	proxy(java.lang.Class itf) Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy.
Component	proxy(java.lang.Class[] itfs) Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy.
Component	singleton() Create a new Component that utilizes singleton pattern when creating instance.
Component	singleton(Pool scope) Create a new Component that utilizes singleton pattern within a scope specified by the provided Pool object when creating instance.

Methods inherited from class jfun.yan.DelegatingComponent

create, equals, getDelegateTarget, getState, getType, hashCode, isConcrete, toString, verify

Methods inherited from class jfun.yan.Component

bean, bean, bean, bind, bind, bindArgument, bindArguments, bindProperties, bindProperty, cast, factory, factory, factory, factory, factory, field, field, field, followedBy, followedBy, followedBy, fromArguments, fromProperties, getter, getter, ifelse, ignoreProperty, incomplete, label, label, map, method, method, method, method, method, mutate, option, optional, optionalParameter, optionalParameters, optionalProperties, optionalProperty, recover, repeat, seal, seq, setter, setter, subsume, synchronize, withArgument, withArgument, withArguments, withArguments, withDefaultArgument, withDefaultProperty, withProperties, withProperties, withProperties, withProperty, withProperty, withState

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DecoratingComponent

public DecoratingComponent(Component cc)

Create a new DeleratingComponent object.

Parameters:

cc - the Component object to decorate.

Method Detail

decorate

protected abstract Component decorate(Component c)

Decorate a Component object.

Parameters:

c - the Component to decorate.

Returns:

the decorated Component.

singleton

public Component singleton()

Description copied from class: Component

Create a new Component that utilizes singleton pattern when creating instance. This new component will still use whatever the creation strategy "this" has, But it guarantees that the result is properly cached so that next time create() is called, the same instance will be returned.

Overrides:

singleton in class Component

Returns:

the new Component.

singleton

public Component singleton(Pool scope)

Description copied from class: Component

Create a new Component that utilizes singleton pattern within a scope specified by the provided Pool object when creating instance.
This new component will still use whatever the creation strategy "this" has, But it guarantees that the result is properly cached so that next time create() is called, the same instance will be returned.

Overrides:

singleton in class Component

Parameters:

scope - the scope of the singleton pattern.

Returns:

the new Component.

guard

public Component guard()

Description copied from class: Component

Decorate this Component so that the new Component object guards against infinite dependency loop.

Overrides:

guard in class Component

Returns:

the new Component object.

proxy

public Component proxy()

Description copied from class: Component

Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy. The dynamic proxy will implement all the public interfaces that the type of "this" component implements.

Overrides:

proxy in class Component

Returns:

the new Component object.

proxy

public Component proxy(java.lang.Class itf)

Description copied from class: Component

Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy.

Overrides:

proxy in class Component

Parameters:

itf - the interface to proxy to.

Returns:

the new Component object.

proxy

public Component proxy(java.lang.Class[] itfs)

Description copied from class: Component

Create a new Component object that uses dynamic proxy to transform the return value 'this' Component creates to a dynamic proxy.

Overrides:

proxy in class Component

Parameters:

itfs - the interfaces to proxy to.

Returns:

the new Component object.

isSingleton

public boolean isSingleton()

Description copied from interface: Creator

Determines if the component always return the same instance and has no side-effect that causes difference when called the second time.

This information may be useful to certain optimizations.

Specified by:

isSingleton in interface Creator

Overrides:

isSingleton in class DelegatingComponent

Returns:

true if it always return the same instance. False if not singleton or non-determinable.