Each proxy instance has an associated invocation handler. - * When a method is invoked on a proxy instance, the method - * invocation is encoded and dispatched to the {@code invoke} - * method of its invocation handler. - * - * @author Peter Jones - * @see Proxy - * @since 1.3 - */ -public interface InvocationHandler { - - /** - * Processes a method invocation on a proxy instance and returns - * the result. This method will be invoked on an invocation handler - * when a method is invoked on a proxy instance that it is - * associated with. - * - * @param proxy the proxy instance that the method was invoked on - * - * @param method the {@code Method} instance corresponding to - * the interface method invoked on the proxy instance. The declaring - * class of the {@code Method} object will be the interface that - * the method was declared in, which may be a superinterface of the - * proxy interface that the proxy class inherits the method through. - * - * @param args an array of objects containing the values of the - * arguments passed in the method invocation on the proxy instance, - * or {@code null} if interface method takes no arguments. - * Arguments of primitive types are wrapped in instances of the - * appropriate primitive wrapper class, such as - * {@code java.lang.Integer} or {@code java.lang.Boolean}. - * - * @return the value to return from the method invocation on the - * proxy instance. If the declared return type of the interface - * method is a primitive type, then the value returned by - * this method must be an instance of the corresponding primitive - * wrapper class; otherwise, it must be a type assignable to the - * declared return type. If the value returned by this method is - * {@code null} and the interface method's return type is - * primitive, then a {@code NullPointerException} will be - * thrown by the method invocation on the proxy instance. If the - * value returned by this method is otherwise not compatible with - * the interface method's declared return type as described above, - * a {@code ClassCastException} will be thrown by the method - * invocation on the proxy instance. - * - * @throws Throwable the exception to throw from the method - * invocation on the proxy instance. The exception's type must be - * assignable either to any of the exception types declared in the - * {@code throws} clause of the interface method or to the - * unchecked exception types {@code java.lang.RuntimeException} - * or {@code java.lang.Error}. If a checked exception is - * thrown by this method that is not assignable to any of the - * exception types declared in the {@code throws} clause of - * the interface method, then an - * {@link UndeclaredThrowableException} containing the - * exception that was thrown by this method will be thrown by the - * method invocation on the proxy instance. - * - * @see UndeclaredThrowableException - */ - public Object invoke(Object proxy, Method method, Object[] args) - throws Throwable; -}