為不同 Bean 設定不同的交易語意

考慮以下情境:您有許多服務層物件,並且想要對它們中的每一個套用完全不同的交易組態。您可以通過定義不同的 <aop:advisor/> 元素,並使用不同的 pointcutadvice-ref 屬性值來實現這一點。

作為比較點,首先假設您的所有服務層類別都定義在根 x.y.service 套件中。為了使在該套件(或子套件)中定義的類別的實例,且名稱以 Service 結尾的所有 Bean 都具有預設交易組態,您可以編寫以下內容:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		https://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/tx
		https://www.springframework.org/schema/tx/spring-tx.xsd
		http://www.springframework.org/schema/aop
		https://www.springframework.org/schema/aop/spring-aop.xsd">

	<aop:config>

		<aop:pointcut id="serviceOperation"
				expression="execution(* x.y.service..*Service.*(..))"/>

		<aop:advisor pointcut-ref="serviceOperation" advice-ref="txAdvice"/>

	</aop:config>

	<!-- these two beans will be transactional... -->
	<bean id="fooService" class="x.y.service.DefaultFooService"/>
	<bean id="barService" class="x.y.service.extras.SimpleBarService"/>

	<!-- ... and these two beans won't -->
	<bean id="anotherService" class="org.xyz.SomeService"/> <!-- (not in the right package) -->
	<bean id="barManager" class="x.y.service.SimpleBarManager"/> <!-- (doesn't end in 'Service') -->

	<tx:advice id="txAdvice">
		<tx:attributes>
			<tx:method name="get*" read-only="true"/>
			<tx:method name="*"/>
		</tx:attributes>
	</tx:advice>

	<!-- other transaction infrastructure beans such as a TransactionManager omitted... -->

</beans>

以下範例示範如何使用完全不同的交易設定來組態兩個不同的 Bean。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		https://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/tx
		https://www.springframework.org/schema/tx/spring-tx.xsd
		http://www.springframework.org/schema/aop
		https://www.springframework.org/schema/aop/spring-aop.xsd">

	<aop:config>

		<aop:pointcut id="defaultServiceOperation"
				expression="execution(* x.y.service.*Service.*(..))"/>

		<aop:pointcut id="noTxServiceOperation"
				expression="execution(* x.y.service.ddl.DefaultDdlManager.*(..))"/>

		<aop:advisor pointcut-ref="defaultServiceOperation" advice-ref="defaultTxAdvice"/>

		<aop:advisor pointcut-ref="noTxServiceOperation" advice-ref="noTxAdvice"/>

	</aop:config>

	<!-- this bean will be transactional (see the 'defaultServiceOperation' pointcut) -->
	<bean id="fooService" class="x.y.service.DefaultFooService"/>

	<!-- this bean will also be transactional, but with totally different transactional settings -->
	<bean id="anotherFooService" class="x.y.service.ddl.DefaultDdlManager"/>

	<tx:advice id="defaultTxAdvice">
		<tx:attributes>
			<tx:method name="get*" read-only="true"/>
			<tx:method name="*"/>
		</tx:attributes>
	</tx:advice>

	<tx:advice id="noTxAdvice">
		<tx:attributes>
			<tx:method name="*" propagation="NEVER"/>
		</tx:attributes>
	</tx:advice>

	<!-- other transaction infrastructure beans such as a TransactionManager omitted... -->

</beans>