io.opentracing.contrib.common

Class WrapperProxy

java.lang.Object

io.opentracing.contrib.common.WrapperProxy

public final class WrapperProxy
extends Object

Utility class for the creation of wrapper proxies.

Method Summary

Modifier and Type	Method and Description
static boolean	isWrapper(Object obj) Tests whether the specified object is a proxy of a wrapped object.
static <T> boolean	isWrapper(T obj, Class<? extends T> wrappedClass) Tests whether the specified object is a proxy of a wrapped instance type matching the provided wrappedClass.
static <T> T	wrap(T obj, T wrapper) Returns a proxy with type <T> of the specified obj wrapping the provided wrapper instance.

Methods inherited from class java.lang.Object

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

Method Detail

wrap

public static <T> T wrap(T obj,
                         T wrapper)

Returns a proxy with type <T> of the specified obj wrapping the provided wrapper instance. Method invocations on the proxy instance will be handled as such:

1. The wrapper instance will be invoked for methods that exist in the wrapper instance.
2. The obj instance will be invoked for methods that do not exist in the wrapper instance.

The type of the returned proxy will be the composition of all super-interfaces of the runtime type of the specified obj instance.

Note: The runtime type of the returned instance will not be of a concrete class, but rather a composition of all super-interfaces of the concrete class <T>. It is therefore not possible to cast the instance returned by this method to a concrete class, but rather any super-interface of the concrete class.

Type Parameters:

T - The type parameter of the specified arguments.

Parameters:

obj - The target object instance to wrap.

wrapper - The wrapping object.

Returns:

a proxy with type <T> of the specified obj wrapping the provided wrapper instance, or, wrapper if obj == wrapper, or if target or wrapper is null.

isWrapper

public static boolean isWrapper(Object obj)

Tests whether the specified object is a proxy of a wrapped object.

Parameters:

obj - The object to test.

Returns:

Whether the specified object is a proxy of a wrapped object.

Throws:

NullPointerException - If obj is null.

isWrapper

public static <T> boolean isWrapper(T obj,
                                    Class<? extends T> wrappedClass)

Tests whether the specified object is a proxy of a wrapped instance type matching the provided wrappedClass.

Type Parameters:

T - The common type of the proxy and wrapped instance.

Parameters:

obj - The object to test.

wrappedClass - The type of the instance wrapped by the specified obj.

Returns:

Whether the specified object is a proxy of a wrapped instance type matching the provided wrappedClass.

Throws:

NullPointerException - If obj or wrappedClass is null.