001/*
002 * Copyright 2002-2017 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.context.support;
018
019import java.util.Set;
020
021import org.springframework.beans.factory.FactoryBean;
022import org.springframework.beans.factory.InitializingBean;
023import org.springframework.core.convert.ConversionService;
024import org.springframework.core.convert.support.ConversionServiceFactory;
025import org.springframework.core.convert.support.DefaultConversionService;
026import org.springframework.core.convert.support.GenericConversionService;
027import org.springframework.lang.Nullable;
028
029/**
030 * A factory providing convenient access to a ConversionService configured with
031 * converters appropriate for most environments. Set the
032 * {@link #setConverters "converters"} property to supplement the default converters.
033 *
034 * <p>This implementation creates a {@link DefaultConversionService}.
035 * Subclasses may override {@link #createConversionService()} in order to return
036 * a {@link GenericConversionService} instance of their choosing.
037 *
038 * <p>Like all {@code FactoryBean} implementations, this class is suitable for
039 * use when configuring a Spring application context using Spring {@code <beans>}
040 * XML. When configuring the container with
041 * {@link org.springframework.context.annotation.Configuration @Configuration}
042 * classes, simply instantiate, configure and return the appropriate
043 * {@code ConversionService} object from a {@link
044 * org.springframework.context.annotation.Bean @Bean} method.
045 *
046 * @author Keith Donald
047 * @author Juergen Hoeller
048 * @author Chris Beams
049 * @since 3.0
050 */
051public class ConversionServiceFactoryBean implements FactoryBean<ConversionService>, InitializingBean {
052
053        @Nullable
054        private Set<?> converters;
055
056        @Nullable
057        private GenericConversionService conversionService;
058
059
060        /**
061         * Configure the set of custom converter objects that should be added:
062         * implementing {@link org.springframework.core.convert.converter.Converter},
063         * {@link org.springframework.core.convert.converter.ConverterFactory},
064         * or {@link org.springframework.core.convert.converter.GenericConverter}.
065         */
066        public void setConverters(Set<?> converters) {
067                this.converters = converters;
068        }
069
070        @Override
071        public void afterPropertiesSet() {
072                this.conversionService = createConversionService();
073                ConversionServiceFactory.registerConverters(this.converters, this.conversionService);
074        }
075
076        /**
077         * Create the ConversionService instance returned by this factory bean.
078         * <p>Creates a simple {@link GenericConversionService} instance by default.
079         * Subclasses may override to customize the ConversionService instance that
080         * gets created.
081         */
082        protected GenericConversionService createConversionService() {
083                return new DefaultConversionService();
084        }
085
086
087        // implementing FactoryBean
088
089        @Override
090        @Nullable
091        public ConversionService getObject() {
092                return this.conversionService;
093        }
094
095        @Override
096        public Class<? extends ConversionService> getObjectType() {
097                return GenericConversionService.class;
098        }
099
100        @Override
101        public boolean isSingleton() {
102                return true;
103        }
104
105}