When Spring Boot is used, Bean definition of PlatformTransactionManager interface implementation class (DataSourceTransactionManager, JpaTransactionManager, JtaTransactionManager, etc ...) corresponding to the usage technology is automatically performed. Can it be used as default? It's a bit subtle, and I think there are some parameters that should be customized. That's it ... This time, I will introduce how to customize PlatformTransactionManager on Spring Boot.
Until Spring Boot 1.4, if you wanted to customize the PlatformTransactionManager, you had to do one of the following:
@Bean method without using the automatic definition of Spring Boot (direct attack method)@Bean
PlatformTransactionManager transactionManager(DataSource dataSource) {
DataSourceTransactionManager transactionManager = new DataSourceTransactionManager(dataSource);
transactionManager.setDefaultTimeout(30);
transactionManager.setRollbackOnCommitFailure(true);
// ...
return transactionManager;
}
@Autowired method@Autowired
void configureTransactionManager(AbstractPlatformTransactionManager transactionManager) { //Beans automatically set by Spring Boot are injected and customized
transactionManager.setDefaultTimeout(30);
transactionManager.setRollbackOnCommitFailure(true);
// ...
}
In addition to the above method, from Spring Boot 1.5, it will be possible to customize by registering the Bean of the implementation class of ʻorg.springframework.boot.autoconfigure.transaction.PlatformTransactionManagerCustomizer` in the DI container.
Excerpt from PlatformTransactionManagerCustomizer
public interface PlatformTransactionManagerCustomizer<T extends PlatformTransactionManager> {
void customize(T transactionManager);
}
I think this mechanism is useful when you want to share customization logic among multiple applications.
Actually ... Spring Boot provides a built-in class that implements the PlatformTransactionManagerCustomizer interface. The built-in implementation provided by Spring Boot allows you to customize the values of the following properties defined in ʻAbstractPlatformTransactionManager`. (gh-7561)
src/main/resources/application.properties
spring.transaction.default-timeout=30
spring.transaction.rollback-on-commit-failure=true
Note:
Regarding the handling of Spring transaction timeout value, "[MyBatis-Spring transaction timeout value is linked from Spring 1.3 !! (How is Spring transaction timeout value used?)](Http: // qiita. com / kazuki43zoo / items / 1ac208a49c1d6ceeb0b8 # spring% E3% 81% AE% E3% 83% 88% E3% 83% A9% E3% 83% B3% E3% 82% B6% E3% 82% AF% E3% 82% B7% E3% 83% A7% E3% 83% B3% E3% 82% BF% E3% 82% A4% E3% 83% A0% E3% 82% A2% E3% 82% A6% E3% 83% 88% E5% 80% A4% E3% 81% A3% E3% 81% A6% E3% 81% A9% E3% 81% 86% E4% BD% BF% E3% 82% 8F% E3% 82% 8C% E3% For the necessity of "82% 8B% E3% 81% AE% E3% 81% 8B)" and "flag for whether to perform rollback processing when an error occurs at commit time", "Spring DataSource TransactionManager If you use it, it may be committed in case of an error !? ".
If you want to share your customization logic with multiple applications, it's a good idea to create and customize an implementation class for PlatformTransactionManagerCustomizer. (Imagine providing it as if it were a common library)
@Component
public class MyPlatformTransactionManagerCustomizer
implements PlatformTransactionManagerCustomizer<AbstractPlatformTransactionManager> {
@Override
public void customize(AbstractPlatformTransactionManager transactionManager) {
// ...Implement customization logic
}
}
Note:
The
customizemethod is called only when thePlatformTransactionManagergenerated by Spring Boot can be assigned to the type specified in the generics of thePlatformTransactionManagerCustomizer.
For application-specific customizations, you can also ad hoc implement the customize method of PlatformTransactionManagerCustomizer using a Java SE 8 supported Lambda expression without creating a class like the one above.
@Bean
PlatformTransactionManagerCustomizer<AbstractPlatformTransactionManager> transactionManagerCustomizer() {
return transactionManager -> {
// ...Implement customization logic
};
}
~~Warning:~~
~~ If you use a Lambda expression ... The call control of the
customizemethod by the type specified in the generics ofPlatformTransactionManagerCustomizerdoes not work (= It is considered thatPlatformTransactionManageris specified in the generics). ...). ~~ ~~ Therefore, if thePlatformTransactionManagergenerated by Spring Boot cannot be assigned to the type specified in the generics ...CalssCastExceptionwill occur, so be careful! !! ~~** 12/30 15:40 added **
If a
ClassCastExceptionoccurs, it will be ignored, so it will behave the same as when the class was created! !! !!
Multiple PlatformTransactionManagerCustomizers can be applied, including the built-in Spring Boot implementation (TransactionProperties). The behavior when multiple PlatformTransactionManagerCustomizers are registered in the DI container is undefined by default. If you want to control the order ...
@ org.springframework.core.annotation.OrderIt can be achieved by doing this, but it seems that it cannot be done after the built-in implementation of Spring Boot (TransactionProperties). (At least ... I couldn't do it after the embedded implementation in my environment, but I don't think it's a problem.)
Although it has not been released yet, starting with Spring Boot 1.5, an interface (PlatformTransactionManagerCustomizer) that supports customizing PlatformTransactionManager has been added ~
That means ...
The following properties, which are likely to be customized frequently, can now be customized with ʻapplication.properties (or ʻapplication.yml) ~
I introduced that.
Spring Boot 1.5 is scheduled to be released in RC1 at the beginning of the year and the official version at the end of January. When RC1 comes out, I'll check the changes from Spring Boot 1.4 (I think).
I think this entry is probably the end of this year's Qiita. I'm thinking of posting as I like next year, so I hope it helps everyone a little. (Please comment if there is something strange or if you want to do more like this !!)
Well, there are only two days left this year ... Have a nice year ~: see_no_evil :: hear_no_evil:: speak_no_evil:
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