Class AbstractClientProxier<T>

java.lang.Object

org.microbean.reference.AbstractClientProxier<T>

Type Parameters:

T - the type of descriptor this implementation uses to represent (normally unloaded) generated classes

All Implemented Interfaces:

ClientProxier

Direct Known Subclasses:

ReflectiveClientProxier

public abstract class AbstractClientProxier<T>
extends Object
implements ClientProxier

A skeletal implementation of the ClientProxier interface.

Author:

Laird Nelson

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractClientProxier(Domain domain)	Creates a new AbstractClientProxier.

Method Summary

Modifier and Type	Method	Description
protected ClassLoader	classLoader(TypeElement e)	Given a TypeElement that is a declared type, returns a ClassLoader suitable for eventually transforming it into a Class.
final <R> R	clientProxy(Request<R> r, Supplier<? extends R> instanceSupplier)	Returns a contextual reference of type R, which is also a ClientProxy<R>, given a Supplier of contextual instances of the appropriate type.
protected Class<?>	clientProxyClass(T t, ClassLoader cl)	Called by the default implementation of the instantiate(ProxySpecification, Supplier) method, converts the supplied class definition into a Class, using the supplied ClassLoader, and returns it (optional operation).
protected final Domain	domain()	Returns the Domain supplied at construction time.
protected T	generate(ProxySpecification ps)	Called indirectly by the default implementation of the instantiate(ProxySpecification, Supplier) method, creates a generated class definition from the information present in the supplied ProxySpecification, and returns it for eventual supplying to an inovcation of the clientProxyClass(Object, ClassLoader) method (optional operation).
protected <R> ClientProxy<R>	instantiate(Class<?> clientProxyClass, Supplier<? extends R> instanceSupplier)	Called by the instantiate(ProxySpecification, Supplier) method, creates a new instance of the supplied clientProxyClass that proxies contextual instances supplied by the supplied instanceSupplier.
protected <R> ClientProxy<R>	instantiate(ProxySpecification ps, Supplier<? extends R> instanceSupplier)	Called indirectly by the clientProxy(Request, Supplier) method when a new ClientProxy<R> instance needs to be created, creates a new instance of a ClientProxy<R> that proxies contextual instances supplied by the supplied instanceSupplier, and returns it.
protected abstract MethodHandles.Lookup	lookup(Class<?> c)	Returns a MethodHandles.Lookup suitable for the supplied Class.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractClientProxier

protected AbstractClientProxier(Domain domain)

Creates a new AbstractClientProxier.

Parameters:

domain - a Domain; must not be null

Throws:

NullPointerException - if domain is null

Method Details

classLoader

protected ClassLoader classLoader(TypeElement e)

Given a TypeElement that is a declared type, returns a ClassLoader suitable for eventually transforming it into a Class.

The default implementation of this method returns the context classloader.

Parameters:

e - a TypeElement; must not be null; must be a declared type

Returns:

a non-null ClassLoader

Throws:

NullPointerException - if e is null

IllegalArgumentException - if e is not a declared type

clientProxy

public final <R> R clientProxy(Request<R> r,
 Supplier<? extends R> instanceSupplier)

Returns a contextual reference of type R, which is also a ClientProxy<R>, given a Supplier of contextual instances of the appropriate type.

This method never returns null.

Specified by:

clientProxy in interface ClientProxier

Type Parameters:

R - the type of the contextual reference

Parameters:

r - the Request necessitating this invocation; must not be null

instanceSupplier - a Supplier of contextual instances of type R; must not be null

Returns:

a contextual reference that is also a ClientProxy<R>; never null

Throws:

NullPointerException - if any argument is null, or if the instantiate(ProxySpecification, Supplier) method, invoked as part of the implementation of this method, returns null

IllegalArgumentException - if the supplied Request is not proxiable for any reason

ReferenceException - if the instantiate(ProxySpecification, Supplier) method throws a checked Exception

See Also:

• instantiate(ProxySpecification, Supplier)
• ClientProxy

clientProxyClass

protected Class<?> clientProxyClass(T t,
 ClassLoader cl)
                             throws ClassNotFoundException

Called by the default implementation of the instantiate(ProxySpecification, Supplier) method, converts the supplied class definition into a Class, using the supplied ClassLoader, and returns it (optional operation).

If an override of the instantiate(ProxySpecification, Supplier) method does something entirely different, this method may never be called.

The default implementation of this method throws an UnsupportedOperationException.

In general, implementations of this method should not call the instantiate(ProxySpecification, Supplier) method, or undefined behavior may result.

Parameters:

t - a class definition; must not be null

cl - a ClassLoader; must not be null

Returns:

a non-null Class

Throws:

NullPointerException - if any argument is null

UnsupportedOperationException - if class generation is not supported by this AbstractClientProxier

ClassNotFoundException - if an invocation of ClassLoader.loadClass(String) fails

See Also:

• instantiate(ProxySpecification, Supplier)

domain

protected final Domain domain()

Returns the Domain supplied at construction time.

Returns:

a non-null Domain

See Also:

• AbstractClientProxier(Domain)

generate

protected T generate(ProxySpecification ps)
              throws Throwable

Called indirectly by the default implementation of the instantiate(ProxySpecification, Supplier) method, creates a generated class definition from the information present in the supplied ProxySpecification, and returns it for eventual supplying to an inovcation of the clientProxyClass(Object, ClassLoader) method (optional operation).

If an override of the instantiate(ProxySpecification, Supplier) method does something entirely different, this method may never be called.

The default implementation of this method throws an UnsupportedOperationException.

Implementations of this method must not call the instantiate(ProxySpecification, Supplier) method, or undefined behavior may result.

Parameters:

ps - a ProxySpecification; must not be null

Returns:

a non-null generated class definition

Throws:

NullPointerException - if ps is null

UnsupportedOperationException - if class generation is unsupported by this AbstractClientProxier implementation

Throwable - if creation of the generated class definition fails

See Also:

• clientProxyClass(Object, ClassLoader)

instantiate

protected <R> ClientProxy<R> instantiate(ProxySpecification ps,
 Supplier<? extends R> instanceSupplier)
                                  throws Throwable

Called indirectly by the clientProxy(Request, Supplier) method when a new ClientProxy<R> instance needs to be created, creates a new instance of a ClientProxy<R> that proxies contextual instances supplied by the supplied instanceSupplier, and returns it.

The default implementation of this method eventually calls the instantiate(Class, Supplier) method with the return value of an indirect invocation of the clientProxyClass(Object, ClassLoader) method and the supplied Supplier and returns the result.

Overrides of this method that do something entirely different are not obligated to call the clientProxyClass(Object, ClassLoader) method or the instantiate(Class, Supplier) method. In such a case, those methods will be effectively orphaned.

Type Parameters:

R - the type of contextual instance being proxied

Parameters:

ps - a ProxySpecification; must not be null

instanceSupplier - a Supplier of contextual instances of the <R> type; must not be null

Returns:

a non-null ClientProxy<R>

Throws:

NullPointerException - if any argument is null

ReferenceException - if instantiation fails

Throwable - if instantiation fails

See Also:

• clientProxyClass(Object, ClassLoader)
• instantiate(Class, Supplier)

instantiate

protected <R> ClientProxy<R> instantiate(Class<?> clientProxyClass,
 Supplier<? extends R> instanceSupplier)
                                  throws Throwable

Called by the instantiate(ProxySpecification, Supplier) method, creates a new instance of the supplied clientProxyClass that proxies contextual instances supplied by the supplied instanceSupplier.

If a subclass overrides the instantiate(ProxySpecification, Supplier) method to do something entirely different, this method may not be called.

Overrides of this method must not call the instantiate(ProxySpecification, Supplier) method or undefined behavior may result.

Type Parameters:

R - the type of contextual instance being proxied

Parameters:

clientProxyClass - a Class assignable to ClientProxy.class and castable to the R type; must not be null

instanceSupplier - a Supplier of contextual instances of the R type; must not be null

Returns:

a non-null ClientProxy<R>

Throws:

NullPointerException - if any argument is null

ReferenceException - if instantiation fails

Throwable - if instantiation fails

See Also:

• instantiate(ProxySpecification, Supplier)

lookup

protected abstract MethodHandles.Lookup lookup(Class<?> c)

Returns a MethodHandles.Lookup suitable for the supplied Class.

Parameters:

c - a Class; must not be null

Returns:

a MethodHandles.Lookup; never null

Throws:

NullPointerException - if c is null

See Also:

• MethodHandles.lookup()
• MethodHandles.Lookup.in(Class)
• MethodHandles.privateLookupIn(Class, Lookup)