001/* 002 * Copyright 2002-2014 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.cache.interceptor; 018 019import java.lang.reflect.Method; 020 021/** 022 * Simple key generator. Returns the parameter itself if a single non-null value 023 * is given, otherwise returns a {@link SimpleKey} of the parameters. 024 * 025 * <p>Unlike {@link DefaultKeyGenerator}, no collisions will occur with the keys 026 * generated by this class. The returned {@link SimpleKey} object can be safely 027 * used with a {@link org.springframework.cache.concurrent.ConcurrentMapCache}, 028 * however, might not be suitable for all {@link org.springframework.cache.Cache} 029 * implementations. 030 * 031 * @author Phillip Webb 032 * @author Juergen Hoeller 033 * @since 4.0 034 * @see SimpleKey 035 * @see DefaultKeyGenerator 036 * @see org.springframework.cache.annotation.CachingConfigurer 037 */ 038public class SimpleKeyGenerator implements KeyGenerator { 039 040 @Override 041 public Object generate(Object target, Method method, Object... params) { 042 return generateKey(params); 043 } 044 045 /** 046 * Generate a key based on the specified parameters. 047 */ 048 public static Object generateKey(Object... params) { 049 if (params.length == 0) { 050 return SimpleKey.EMPTY; 051 } 052 if (params.length == 1) { 053 Object param = params[0]; 054 if (param != null && !param.getClass().isArray()) { 055 return param; 056 } 057 } 058 return new SimpleKey(params); 059 } 060 061}