Package org.perfectable.introspection.proxy

Class LazyInitialization

java.lang.Object

org.perfectable.introspection.proxy.LazyInitialization

public final class LazyInitialization
extends Object

Helper class to create proxy which delegate invocation to lazily-initialized instance.

Proxies are created by createProxy(java.lang.Class<T>, org.perfectable.introspection.proxy.LazyInitialization.Initializer<? extends T>).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	LazyInitialization.Initializer<T>	Provider interface for proxy delegation target.
static interface	LazyInitialization.Proxy<T>	Additional interface that all proxies created by createProxy(java.lang.Class<T>, org.perfectable.introspection.proxy.LazyInitialization.Initializer<? extends T>) will implement.

Method Summary

Modifier and Type	Method	Description
static <T> T	createProxy(Class<T> resultClass, LazyInitialization.Initializer<? extends T> initializer)	Creates a proxy that forwards invocations to lazily initialized instance.

Methods inherited from class java.lang.Object

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

Method Detail

createProxy

public static <T> T createProxy(Class<T> resultClass,
                                LazyInitialization.Initializer<? extends T> initializer)

Creates a proxy that forwards invocations to lazily initialized instance.

On any method call on resulting proxy it will either initialize instance and cache it, or use existing instance, and delegate the call to it, returning the result or rethrowing exception of the call. There are two exceptions of this rule:

• Object.finalize() is always ignored when called on proxy
• Methods from LazyInitialization.Proxy interface are treated specially and handled with separate route. They won't necessarily initialize the proxy and won't be forwarded to the target.

Proxies will have resultClass as a superclass/superinterface. Additionally, proxy class will implement LazyInitialization.Proxy interface. This wont be reflected in the compile-time type, but it can be checked by instanceof and it can be casted to it.

Type Parameters:

T - type of proxy

Parameters:

resultClass - class or interface that proxy has to implement. This is also a superclass/superinterface of initialized instance

initializer - method of initializing actual delegation target

Returns:

proxy object