org.springframework.transaction.annotation.TransactionManagementConfigurer Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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
*
* https://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.transaction.annotation;
import org.springframework.transaction.PlatformTransactionManager;
/**
* Interface to be implemented by @{@link org.springframework.context.annotation.Configuration
* Configuration} classes annotated with @{@link EnableTransactionManagement} that wish to
* or need to explicitly specify the default {@link PlatformTransactionManager} bean to be
* used for annotation-driven transaction management, as opposed to the default approach
* of a by-type lookup. One reason this might be necessary is if there are two
* {@code PlatformTransactionManager} beans present in the container.
*
* See @{@link EnableTransactionManagement} for general examples and context;
* see {@link #annotationDrivenTransactionManager()} for detailed instructions.
*
*
Note that in by-type lookup disambiguation cases, an alternative approach to
* implementing this interface is to simply mark one of the offending
* {@code PlatformTransactionManager} {@code @Bean} methods as
* {@link org.springframework.context.annotation.Primary @Primary}.
* This is even generally preferred since it doesn't lead to early initialization
* of the {@code PlatformTransactionManager} bean.
*
* @author Chris Beams
* @since 3.1
* @see EnableTransactionManagement
* @see org.springframework.context.annotation.Primary
*/
public interface TransactionManagementConfigurer {
/**
* Return the default transaction manager bean to use for annotation-driven database
* transaction management, i.e. when processing {@code @Transactional} methods.
*
There are two basic approaches to implementing this method:
*
1. Implement the method and annotate it with {@code @Bean}
* In this case, the implementing {@code @Configuration} class implements this method,
* marks it with {@code @Bean} and configures and returns the transaction manager
* directly within the method body:
*
* @Bean
* @Override
* public PlatformTransactionManager annotationDrivenTransactionManager() {
* return new DataSourceTransactionManager(dataSource());
* }
* 2. Implement the method without {@code @Bean} and delegate to another existing
* {@code @Bean} method
*
* @Bean
* public PlatformTransactionManager txManager() {
* return new DataSourceTransactionManager(dataSource());
* }
*
* @Override
* public PlatformTransactionManager annotationDrivenTransactionManager() {
* return txManager(); // reference the existing {@code @Bean} method above
* }
* If taking approach #2, be sure that only one of the methods is marked
* with {@code @Bean}!
* In either scenario #1 or #2, it is important that the
* {@code PlatformTransactionManager} instance is managed as a Spring bean within the
* container as all {@code PlatformTransactionManager} implementations take advantage
* of Spring lifecycle callbacks such as {@code InitializingBean} and
* {@code BeanFactoryAware}.
*/
PlatformTransactionManager annotationDrivenTransactionManager();
}