Explicit notes on class/method-level semantics in class hierarchies
Issue: SPR-17445
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@@ -27,7 +27,12 @@ import org.springframework.core.annotation.AliasFor;
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import org.springframework.transaction.TransactionDefinition;
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/**
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* Describes transaction attributes on a method or class.
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* Describes a transaction attribute on an individual method or on a class.
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*
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* <p>At the class level, this annotation applies as a default to all methods of
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* the declaring class and its subclasses. Note that it does not apply to ancestor
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* classes up the class hierarchy; methods need to be locally redeclared in order
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* to participate in a subclass-level annotation.
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*
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* <p>This annotation type is generally directly comparable to Spring's
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* {@link org.springframework.transaction.interceptor.RuleBasedTransactionAttribute}
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@@ -1100,8 +1100,19 @@ Consider the following class definition:
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----
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====
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When the preceding POJO is defined as a bean in a Spring IoC container, you can make the bean instance
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transactional by adding only one line of XML configuration:
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Used at the class level as above, the annotation indicates a default for all methods
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of the declaring class (as well as its subclasses). Alternatively, each method can
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get annotated individually. Note that a class-level annotation does not apply to
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ancestor classes up the class hierarchy; in such a scenario, methods need to be
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locally redeclared in order to participate in a subclass-level annotation.
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When a POJO class such as the one above is defined as a bean in a Spring context,
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you can make the bean instance transactional through an `@EnableTransactionManagement`
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annotation in a `@Configuration` class. See the
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{api-spring-framework}/transaction/annotation/EnableTransactionManagement.html[javadoc]
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for full details.
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In XML configuration, the `<tx:annotation-driven/>` tag provides similar convenience:
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====
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[source,xml,indent=0]
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@@ -1126,6 +1137,7 @@ transactional by adding only one line of XML configuration:
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<!-- enable the configuration of transactional behavior based on annotations -->
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<tx:annotation-driven transaction-manager="txManager"/><!-- a PlatformTransactionManager is still required --> <1>
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<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
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<!-- (this dependency is defined somewhere else) -->
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<property name="dataSource" ref="dataSource"/>
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@@ -1144,11 +1156,6 @@ if the bean name of the `PlatformTransactionManager` that you want to wire in ha
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dependency-inject has any other name, you have to use the `transaction-manager` attribute,
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as in the preceding example.
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NOTE: If you use Java-based configuration, the `@EnableTransactionManagement` annotation
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provides equivalent support . You can add the annotation to a `@Configuration` class.
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See the {api-spring-framework}/transaction/annotation/EnableTransactionManagement.html[javadoc]
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for full details.
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.Method visibility and `@Transactional`
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****
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When you use proxies, you should apply the `@Transactional` annotation only to methods
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@@ -1158,13 +1165,13 @@ method does not exhibit the configured transactional settings. If you need to an
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non-public methods, consider using AspectJ (described later).
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****
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You can place the `@Transactional` annotation before an interface definition, a method
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You can apply the `@Transactional` annotation to an interface definition, a method
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on an interface, a class definition, or a public method on a class. However, the
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mere presence of the `@Transactional` annotation is not enough to activate the
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transactional behavior. The `@Transactional` annotation is merely metadata that can be
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consumed by some runtime infrastructure that is `@Transactional`-aware and that can use
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the metadata to configure the appropriate beans with transactional behavior. In the
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preceding example, the `<tx:annotation-driven/>` element switches on the
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transactional behavior. The `@Transactional` annotation is merely metadata that can
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be consumed by some runtime infrastructure that is `@Transactional`-aware and that
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can use the metadata to configure the appropriate beans with transactional behavior.
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In the preceding example, the `<tx:annotation-driven/>` element switches on the
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transactional behavior.
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TIP: The Spring team recommends that you annotate only concrete classes (and methods of
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@@ -1173,9 +1180,8 @@ You certainly can place the `@Transactional` annotation on an interface (or an i
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method), but this works only as you would expect it to if you use interface-based
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proxies. The fact that Java annotations are not inherited from interfaces means that,
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if you use class-based proxies (`proxy-target-class="true"`) or the weaving-based
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aspect (`mode="aspectj"`), the transaction settings are not recognized by the
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proxying and weaving infrastructure, and the object is not wrapped in a
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transactional proxy, which would be decidedly bad.
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aspect (`mode="aspectj"`), the transaction settings are not recognized by the proxying
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and weaving infrastructure, and the object is not wrapped in a transactional proxy.
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NOTE: In proxy mode (which is the default), only external method calls coming in through
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the proxy are intercepted. This means that self-invocation (in effect, a method within
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