org.springframework.transaction.annotation

## Interface TransactionManagementConfigurer

-     public interface TransactionManagementConfigurer

  Interface to be implemented by @`Configuration` classes annotated with @`EnableTransactionManagement` that wish or need to specify explicitly the `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 `PlatformTransactionManager` beans present in the container.

  See @`EnableTransactionManagement` for general examples and context; see `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 `PlatformTransactionManager` `@Bean` methods as @`Primary`.

  Since:
    3.1
  Author:
    Chris Beams
  See Also:
    `EnableTransactionManagement`, `Primary`

- - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `PlatformTransactionManager` | `annotationDrivenTransactionManager()` Return the transaction manager bean to use for annotation-driven database transaction management, i.e.

- - ### Method Detail

    - #### annotationDrivenTransactionManager

          PlatformTransactionManager annotationDrivenTransactionManager()

      Return the transaction manager bean to use for annotation-driven database transaction management, i.e. when processing `@Transactional` methods.

      There are two basic approaches to implementing this method:

      ### 1. Implement the method and annotate it with `@Bean`

      In this case, the implementing `@Configuration` class implements this method, marks it with `@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 `@Bean` and delegate to another existing `@Bean` method

           @Bean
           public PlatformTransactionManager txManager() {
               return new DataSourceTransactionManager(dataSource());
           }

           @Override
           public PlatformTransactionManager annotationDrivenTransactionManager() {
               return txManager(); // reference the existing @Bean method above
           }

      If taking approach #2, be sure that only one of the methods is marked with `@Bean`!

      In either scenario #1 or #2, it is important that the `PlatformTransactionManager` instance is managed as a Spring bean within the container as all `PlatformTransactionManager` implementations take advantage of Spring lifecycle callbacks such as `InitializingBean` and `BeanFactoryAware`.