/* * Copyright 2002-2005 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.alibaba.spring.core.convert.support; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.beans.factory.config.ConfigurableBeanFactory; import org.springframework.beans.factory.config.SingletonBeanRegistry; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.core.convert.ConversionService; import org.springframework.format.support.DefaultFormattingConversionService; import static com.alibaba.spring.util.BeanUtils.getBeanIfAvailable; import static com.alibaba.spring.util.BeanUtils.isBeanPresent; import static java.lang.String.format; import static org.springframework.context.ConfigurableApplicationContext.CONVERSION_SERVICE_BEAN_NAME; /** * The class to resolve a singleton instance of {@link ConversionService} that may be retrieved from Spring * {@link ConfigurableApplicationContext#CONVERSION_SERVICE_BEAN_NAME built-in bean} or create a new one. * * @see ConversionService * @see ConfigurableApplicationContext#CONVERSION_SERVICE_BEAN_NAME * @see SingletonBeanRegistry#registerSingleton(String, Object) * @since 1.0.6 */ public class ConversionServiceResolver { /** * The bean name of a singleton instance of {@link ConversionService} has been resolved */ public static final String RESOLVED_CONVERSION_SERVICE_BEAN_NAME = "resolved-" + CONVERSION_SERVICE_BEAN_NAME; private final Log logger = LogFactory.getLog(getClass()); private final ConfigurableBeanFactory beanFactory; public ConversionServiceResolver(ConfigurableBeanFactory beanFactory) { this.beanFactory = beanFactory; } public ConversionService resolve() { return resolve(true); } public ConversionService resolve(boolean requireToRegister) { ConversionService conversionService = getResolvedBeanIfAvailable(); if (conversionService == null) { // If not resolved, try to get from ConfigurableBeanFactory conversionService = getFromBeanFactory(); } if (conversionService == null) { // If not found, try to get the bean from BeanFactory debug("The conversionService instance can't be found in Spring ConfigurableBeanFactory.getConversionService()"); conversionService = getIfAvailable(); } if (conversionService == null) { // If not found, will create an instance of ConversionService as default conversionService = createDefaultConversionService(); } if (!isBeanPresent(beanFactory, RESOLVED_CONVERSION_SERVICE_BEAN_NAME, ConversionService.class) && requireToRegister) { // To register a singleton into SingletonBeanRegistry(ConfigurableBeanFactory) beanFactory.registerSingleton(RESOLVED_CONVERSION_SERVICE_BEAN_NAME, conversionService); } return conversionService; } private ConversionService getResolvedBeanIfAvailable() { return getBeanIfAvailable(beanFactory, RESOLVED_CONVERSION_SERVICE_BEAN_NAME, ConversionService.class); } private ConversionService getFromBeanFactory() { return beanFactory.getConversionService(); } private ConversionService getIfAvailable() { return getBeanIfAvailable(beanFactory, CONVERSION_SERVICE_BEAN_NAME, ConversionService.class); } /** * Create the instance of {@link DefaultFormattingConversionService} as the default, * this method is allow to be override by the sub-class. * * @return non-null */ protected ConversionService createDefaultConversionService() { return new DefaultFormattingConversionService(); } private void debug(String message, Object... args) { if (logger.isDebugEnabled()) { logger.debug(format(message, args)); } } }