    001    // Copyright 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.plastic;
    016
    017    /**
    018     * The result of a {@linkplain MethodHandle#invoke(Object, Object...) method invocation}, which
    019     * encapsulates the actual return value (if any), as well as any checked exception.
    020     */
    021    public interface MethodInvocationResult
    022    {
    023        /**
    024         * Returns the actual value returned from the method invocation, if any. This will be null
    025         * if the invocation threw a checked exception, or the method itself is void.
    026         */
    027        Object getReturnValue();
    028
    029        /**
    030         * If the invocation threw a checked exception, then this method throws that exception wrapped
    031         * as the cause of a new RuntimeException. Otherwise, this method does nothing.
    032         */
    033        void rethrow();
    034
    035        /** Returns true if the method invocation threw a checked exception. */
    036        boolean didThrowCheckedException();
    037
    038        /**
    039         * Retrieves the checked exception assignable to the indicated type, or null if
    040         * the invocation did not throw a checked exception or the thrown exception is not
    041         * assignable.
    042         */
    043        <T extends Throwable> T getCheckedException(Class<T> exceptionType);
    044    }