001/*
002 * Copyright 2002-2013 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.expression;
018
019/**
020 * MethodExecutors are built by the resolvers and can be cached by the infrastructure to
021 * repeat an operation quickly without going back to the resolvers. For example, the
022 * particular method to run on an object may be discovered by the reflection method
023 * resolver - it will then build a MethodExecutor that executes that method and the
024 * MethodExecutor can be reused without needing to go back to the resolver to discover
025 * the method again.
026 *
027 * <p>They can become stale, and in that case should throw an AccessException:
028 * This will cause the infrastructure to go back to the resolvers to ask for a new one.
029 *
030 * @author Andy Clement
031 * @since 3.0
032 */
033public interface MethodExecutor {
034
035        /**
036         * Execute a command using the specified arguments, and using the specified expression state.
037         * @param context the evaluation context in which the command is being executed
038         * @param target the target object of the call - null for static methods
039         * @param arguments the arguments to the executor, should match (in terms of number
040         * and type) whatever the command will need to run
041         * @return the value returned from execution
042         * @throws AccessException if there is a problem executing the command or the
043         * MethodExecutor is no longer valid
044         */
045        TypedValue execute(EvaluationContext context, Object target, Object... arguments) throws AccessException;
046
047}