使用ImportBeanDefinitionRegistrar动

ImportBeanDefinitionRegistrar用法大体和BeanDefinitionRegistryPostProcessor相同，但是值得注意的是ImportBeanDefinitionRegistrar只能通过由其它类import的方式来加载，通常是主启动类类或者注解。
BeanDefinitionRegistryPostProcessor用法如下：
BeanDefinitionRegistryPostProcessor
接口定义如下：

/*
 * Copyright 2002-2013 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 org.springframework.context.annotation;

import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
import org.springframework.core.type.AnnotationMetadata;

/**
 * Interface to be implemented by types that register additional bean definitions when
 * processing @{@link Configuration} classes. Useful when operating at the bean definition
 * level (as opposed to {@code @Bean} method/instance level) is desired or necessary.
 *
 * <p>Along with {@code @Configuration} and {@link ImportSelector}, classes of this type
 * may be provided to the @{@link Import} annotation (or may also be returned from an
 * {@code ImportSelector}).
 *
 * <p>An {@link ImportBeanDefinitionRegistrar} may implement any of the following
 * {@link org.springframework.beans.factory.Aware Aware} interfaces, and their respective
 * methods will be called prior to {@link #registerBeanDefinitions}:
 * <ul>
 * <li>{@link org.springframework.context.EnvironmentAware EnvironmentAware}</li>
 * <li>{@link org.springframework.beans.factory.BeanFactoryAware BeanFactoryAware}
 * <li>{@link org.springframework.beans.factory.BeanClassLoaderAware BeanClassLoaderAware}
 * <li>{@link org.springframework.context.ResourceLoaderAware ResourceLoaderAware}
 * </ul>
 *
 * <p>See implementations and associated unit tests for usage examples.
 *
 * @author Chris Beams
 * @since 3.1
 * @see Import
 * @see ImportSelector
 * @see Configuration
 */
public interface ImportBeanDefinitionRegistrar {

    /**
     * Register bean definitions as necessary based on the given annotation metadata of
     * the importing {@code @Configuration} class.
     * <p>Note that {@link BeanDefinitionRegistryPostProcessor} types may <em>not</em> be
     * registered here, due to lifecycle constraints related to {@code @Configuration}
     * class processing.
     * @param importingClassMetadata annotation metadata of the importing class
     * @param registry current bean definition registry
     */
    public void registerBeanDefinitions(
            AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry);

}

使用示例如下：

@SpringBootApplication
@ComponentScan
@RestController
@EnableConfigurationProperties(RedisProp.class)
@Import(DataConfig2.class)
public class TestApplication

public class DataConfig2 implements ImportBeanDefinitionRegistrar {
    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        BeanDefinition beanDe = BeanDefinitionBuilder.rootBeanDefinition(Datasoure.class)
                .addConstructorArgValue("datasoure2").getBeanDefinition();
        registry.registerBeanDefinition("soure2", beanDe);
    }
}