Using @Transactional

In addition to the XML-based declarative approach to transaction configuration, you can use an annotation-based approach. Declaring transaction semantics directly in the Java source code puts the declarations much closer to the affected code. There is not much danger of undue coupling, because code that is meant to be used transactionally is almost always deployed that way anyway.

The standard jakarta.transaction.Transactional annotation is also supported as a drop-in replacement to Spring’s own annotation. Please refer to the JTA documentation for more details.

The ease-of-use afforded by the use of the @Transactional annotation is best illustrated with an example, which is explained in the text that follows. Consider the following class definition:

  • Java

  • Kotlin

// the service class that we want to make transactional
@Transactional
public class DefaultFooService implements FooService {

	@Override
	public Foo getFoo(String fooName) {
		// ...
	}

	@Override
	public Foo getFoo(String fooName, String barName) {
		// ...
	}

	@Override
	public void insertFoo(Foo foo) {
		// ...
	}

	@Override
	public void updateFoo(Foo foo) {
		// ...
	}
}
// the service class that we want to make transactional
@Transactional
class DefaultFooService : FooService {

	override fun getFoo(fooName: String): Foo {
		// ...
	}

	override fun getFoo(fooName: String, barName: String): Foo {
		// ...
	}

	override fun insertFoo(foo: Foo) {
		// ...
	}

	override fun updateFoo(foo: Foo) {
		// ...
	}
}

Used at the class level as above, the annotation indicates a default for all methods of the declaring class (as well as its subclasses). Alternatively, each method can be annotated individually. See method visibility for further details on which methods Spring considers transactional. Note that a class-level annotation does not apply to ancestor classes up the class hierarchy; in such a scenario, inherited methods need to be locally redeclared in order to participate in a subclass-level annotation.

When a POJO class such as the one above is defined as a bean in a Spring context, you can make the bean instance transactional through an @EnableTransactionManagement annotation in a @Configuration class. See the javadoc for full details.

In XML configuration, the <tx:annotation-driven/> tag provides similar convenience:

<!-- from the file 'context.xml' -->
<?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">

	<!-- this is the service object that we want to make transactional -->
	<bean id="fooService" class="x.y.service.DefaultFooService"/>

	<!-- enable the configuration of transactional behavior based on annotations -->
	<!-- a TransactionManager is still required -->
	<tx:annotation-driven transaction-manager="txManager"/> (1)

	<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<!-- (this dependency is defined somewhere else) -->
		<property name="dataSource" ref="dataSource"/>
	</bean>

	<!-- other <bean/> definitions here -->

</beans>
1 The line that makes the bean instance transactional.
You can omit the transaction-manager attribute in the <tx:annotation-driven/> tag if the bean name of the TransactionManager that you want to wire in has the name transactionManager. If the TransactionManager bean that you want to dependency-inject has any other name, you have to use the transaction-manager attribute, as in the preceding example.

Reactive transactional methods use reactive return types in contrast to imperative programming arrangements as the following listing shows:

  • Java

  • Kotlin

// the reactive service class that we want to make transactional
@Transactional
public class DefaultFooService implements FooService {

	@Override
	public Publisher<Foo> getFoo(String fooName) {
		// ...
	}

	@Override
	public Mono<Foo> getFoo(String fooName, String barName) {
		// ...
	}

	@Override
	public Mono<Void> insertFoo(Foo foo) {
		// ...
	}

	@Override
	public Mono<Void> updateFoo(Foo foo) {
		// ...
	}
}
// the reactive service class that we want to make transactional
@Transactional
class DefaultFooService : FooService {

	override fun getFoo(fooName: String): Flow<Foo> {
		// ...
	}

	override fun getFoo(fooName: String, barName: String): Mono<Foo> {
		// ...
	}

	override fun insertFoo(foo: Foo): Mono<Void> {
		// ...
	}

	override fun updateFoo(foo: Foo): Mono<Void> {
		// ...
	}
}

Note that there are special considerations for the returned Publisher with regards to Reactive Streams cancellation signals. See the Cancel Signals section under "Using the TransactionalOperator" for more details.

Method visibility and @Transactional in proxy mode

The @Transactional annotation is typically used on methods with public visibility. As of 6.0, protected or package-visible methods can also be made transactional for class-based proxies by default. Note that transactional methods in interface-based proxies must always be public and defined in the proxied interface. For both kinds of proxies, only external method calls coming in through the proxy are intercepted.

If you prefer consistent treatment of method visibility across the different kinds of proxies (which was the default up until 5.3), consider specifying publicMethodsOnly:

/**
 * Register a custom AnnotationTransactionAttributeSource with the
 * publicMethodsOnly flag set to true to consistently ignore non-public methods.
 * @see ProxyTransactionManagementConfiguration#transactionAttributeSource()
 */
@Bean
TransactionAttributeSource transactionAttributeSource() {
	return new AnnotationTransactionAttributeSource(true);
}

The Spring TestContext Framework supports non-private @Transactional test methods by default as well. See Transaction Management in the testing chapter for examples.

You can apply the @Transactional annotation to an interface definition, a method on an interface, a class definition, or a method on a class. However, the mere presence of the @Transactional annotation is not enough to activate the transactional behavior. The @Transactional annotation is merely metadata that can be consumed by corresponding runtime infrastructure which uses that metadata to configure the appropriate beans with transactional behavior. In the preceding example, the <tx:annotation-driven/> element switches on actual transaction management at runtime.

The Spring team recommends that you annotate methods of concrete classes with the @Transactional annotation, rather than relying on annotated methods in interfaces, even if the latter does work for interface-based and target-class proxies as of 5.0. Since Java annotations are not inherited from interfaces, interface-declared annotations are still not recognized by the weaving infrastructure when using AspectJ mode, so the aspect does not get applied. As a consequence, your transaction annotations may be silently ignored: Your code might appear to "work" until you test a rollback scenario.
In proxy mode (which is the default), only external method calls coming in through the proxy are intercepted. This means that self-invocation (in effect, a method within the target object calling another method of the target object) does not lead to an actual transaction at runtime even if the invoked method is marked with @Transactional. Also, the proxy must be fully initialized to provide the expected behavior, so you should not rely on this feature in your initialization code — e.g. in a @PostConstruct method.

Consider using AspectJ mode (see the mode attribute in the following table) if you expect self-invocations to be wrapped with transactions as well. In this case, there is no proxy in the first place. Instead, the target class is woven (that is, its byte code is modified) to support @Transactional runtime behavior on any kind of method.

Table 1. Annotation driven transaction settings
XML Attribute Annotation Attribute Default Description

transaction-manager

N/A (see TransactionManagementConfigurer javadoc)

transactionManager

Name of the transaction manager to use. Required only if the name of the transaction manager is not transactionManager, as in the preceding example.

mode

mode

proxy

The default mode (proxy) processes annotated beans to be proxied by using Spring’s AOP framework (following proxy semantics, as discussed earlier, applying to method calls coming in through the proxy only). The alternative mode (aspectj) instead weaves the affected classes with Spring’s AspectJ transaction aspect, modifying the target class byte code to apply to any kind of method call. AspectJ weaving requires spring-aspects.jar in the classpath as well as having load-time weaving (or compile-time weaving) enabled. (See Spring configuration for details on how to set up load-time weaving.)

proxy-target-class

proxyTargetClass

false

Applies to proxy mode only. Controls what type of transactional proxies are created for classes annotated with the @Transactional annotation. If the proxy-target-class attribute is set to true, class-based proxies are created. If proxy-target-class is false or if the attribute is omitted, then standard JDK interface-based proxies are created. (See Proxying Mechanisms for a detailed examination of the different proxy types.)

order

order

Ordered.LOWEST_PRECEDENCE

Defines the order of the transaction advice that is applied to beans annotated with @Transactional. (For more information about the rules related to ordering of AOP advice, see Advice Ordering.) No specified ordering means that the AOP subsystem determines the order of the advice.

The default advice mode for processing @Transactional annotations is proxy, which allows for interception of calls through the proxy only. Local calls within the same class cannot get intercepted that way. For a more advanced mode of interception, consider switching to aspectj mode in combination with compile-time or load-time weaving.
The proxy-target-class attribute controls what type of transactional proxies are created for classes annotated with the @Transactional annotation. If proxy-target-class is set to true, class-based proxies are created. If proxy-target-class is false or if the attribute is omitted, standard JDK interface-based proxies are created. (See Proxying Mechanisms for a discussion of the different proxy types.)
@EnableTransactionManagement and <tx:annotation-driven/> look for @Transactional only on beans in the same application context in which they are defined. This means that, if you put annotation-driven configuration in a WebApplicationContext for a DispatcherServlet, it checks for @Transactional beans only in your controllers and not in your services. See MVC for more information.

The most derived location takes precedence when evaluating the transactional settings for a method. In the case of the following example, the DefaultFooService class is annotated at the class level with the settings for a read-only transaction, but the @Transactional annotation on the updateFoo(Foo) method in the same class takes precedence over the transactional settings defined at the class level.

  • Java

  • Kotlin

@Transactional(readOnly = true)
public class DefaultFooService implements FooService {

	public Foo getFoo(String fooName) {
		// ...
	}

	// these settings have precedence for this method
	@Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
	public void updateFoo(Foo foo) {
		// ...
	}
}
@Transactional(readOnly = true)
class DefaultFooService : FooService {

	override fun getFoo(fooName: String): Foo {
		// ...
	}

	// these settings have precedence for this method
	@Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
	override fun updateFoo(foo: Foo) {
		// ...
	}
}

@Transactional Settings

The @Transactional annotation is metadata that specifies that an interface, class, or method must have transactional semantics (for example, "start a brand new read-only transaction when this method is invoked, suspending any existing transaction"). The default @Transactional settings are as follows:

  • The propagation setting is PROPAGATION_REQUIRED.

  • The isolation level is ISOLATION_DEFAULT.

  • The transaction is read-write.

  • The transaction timeout defaults to the default timeout of the underlying transaction system, or to none if timeouts are not supported.

  • Any RuntimeException or Error triggers rollback, and any checked Exception does not.

You can change these default settings. The following table summarizes the various properties of the @Transactional annotation:

Table 2. @Transactional Settings
Property Type Description

value

String

Optional qualifier that specifies the transaction manager to be used.

transactionManager

String

Alias for value.

label

Array of String labels to add an expressive description to the transaction.

Labels may be evaluated by transaction managers to associate implementation-specific behavior with the actual transaction.

propagation

enum: Propagation

Optional propagation setting.

isolation

enum: Isolation

Optional isolation level. Applies only to propagation values of REQUIRED or REQUIRES_NEW.

timeout

int (in seconds of granularity)

Optional transaction timeout. Applies only to propagation values of REQUIRED or REQUIRES_NEW.

timeoutString

String (in seconds of granularity)

Alternative for specifying the timeout in seconds as a String value — for example, as a placeholder.

readOnly

boolean

Read-write versus read-only transaction. Only applicable to values of REQUIRED or REQUIRES_NEW.

rollbackFor

Array of Class objects, which must be derived from Throwable.

Optional array of exception types that must cause rollback.

rollbackForClassName

Array of exception name patterns.

Optional array of exception name patterns that must cause rollback.

noRollbackFor

Array of Class objects, which must be derived from Throwable.

Optional array of exception types that must not cause rollback.

noRollbackForClassName

Array of exception name patterns.

Optional array of exception name patterns that must not cause rollback.

See Rollback rules for further details on rollback rule semantics, patterns, and warnings regarding possible unintentional matches for pattern-based rollback rules.

Currently, you cannot have explicit control over the name of a transaction, where 'name' means the transaction name that appears in a transaction monitor and in logging output. For declarative transactions, the transaction name is always the fully-qualified class name + . + the method name of the transactionally advised class. For example, if the handlePayment(..) method of the BusinessService class started a transaction, the name of the transaction would be: com.example.BusinessService.handlePayment.

Multiple Transaction Managers with @Transactional

Most Spring applications need only a single transaction manager, but there may be situations where you want multiple independent transaction managers in a single application. You can use the value or transactionManager attribute of the @Transactional annotation to optionally specify the identity of the TransactionManager to be used. This can either be the bean name or the qualifier value of the transaction manager bean. For example, using the qualifier notation, you can combine the following Java code with the following transaction manager bean declarations in the application context:

  • Java

  • Kotlin

public class TransactionalService {

	@Transactional("order")
	public void setSomething(String name) { ... }

	@Transactional("account")
	public void doSomething() { ... }

	@Transactional("reactive-account")
	public Mono<Void> doSomethingReactive() { ... }
}
class TransactionalService {

	@Transactional("order")
	fun setSomething(name: String) {
		// ...
	}

	@Transactional("account")
	fun doSomething() {
		// ...
	}

	@Transactional("reactive-account")
	fun doSomethingReactive(): Mono<Void> {
		// ...
	}
}

The following listing shows the bean declarations:

<tx:annotation-driven/>

	<bean id="transactionManager1" class="org.springframework.jdbc.support.JdbcTransactionManager">
		...
		<qualifier value="order"/>
	</bean>

	<bean id="transactionManager2" class="org.springframework.jdbc.support.JdbcTransactionManager">
		...
		<qualifier value="account"/>
	</bean>

	<bean id="transactionManager3" class="org.springframework.data.r2dbc.connection.R2dbcTransactionManager">
		...
		<qualifier value="reactive-account"/>
	</bean>

In this case, the individual methods on TransactionalService run under separate transaction managers, differentiated by the order, account, and reactive-account qualifiers. The default <tx:annotation-driven> target bean name, transactionManager, is still used if no specifically qualified TransactionManager bean is found.

Custom Composed Annotations

If you find you repeatedly use the same attributes with @Transactional on many different methods, Spring’s meta-annotation support lets you define custom composed annotations for your specific use cases. For example, consider the following annotation definitions:

  • Java

  • Kotlin

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Transactional(transactionManager = "order", label = "causal-consistency")
public @interface OrderTx {
}

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Transactional(transactionManager = "account", label = "retryable")
public @interface AccountTx {
}
@Target(AnnotationTarget.FUNCTION, AnnotationTarget.TYPE)
@Retention(AnnotationRetention.RUNTIME)
@Transactional(transactionManager = "order", label = ["causal-consistency"])
annotation class OrderTx

@Target(AnnotationTarget.FUNCTION, AnnotationTarget.TYPE)
@Retention(AnnotationRetention.RUNTIME)
@Transactional(transactionManager = "account", label = ["retryable"])
annotation class AccountTx

The preceding annotations let us write the example from the previous section as follows:

  • Java

  • Kotlin

public class TransactionalService {

	@OrderTx
	public void setSomething(String name) {
		// ...
	}

	@AccountTx
	public void doSomething() {
		// ...
	}
}
class TransactionalService {

	@OrderTx
	fun setSomething(name: String) {
		// ...
	}

	@AccountTx
	fun doSomething() {
		// ...
	}
}

In the preceding example, we used the syntax to define the transaction manager qualifier and transactional labels, but we could also have included propagation behavior, rollback rules, timeouts, and other features.