引言： 在Spring中@Transactional提供一种控制事务管理的快捷手段，但是很多人都只是@Transactional简单使用，并未深入了解，其各个配置项的使用方法，本文将深入讲解各个配置项的使用。
1. @Transactional的定义
Spring中的@Transactional基于动态代理的机制，提供了一种透明的事务管理机制，方便快捷解决在开发中碰到的问题。在现实中，实际的问题往往比我们预期的要复杂很多，这就要求对@Transactional有深入的了解，以来应对复杂问题。
首先我们来看看@Transactional的代码定义：
@Target({ElementType.METHOD, ElementType.TYPE})@Retention(RetentionPolicy.RUNTIME)@Inherited@Documentedpublic @interface Transactional {/** * A qualifier value for the specified transaction. * <p>May be used to determine the target transaction manager, * matching the qualifier value (or the bean name) of a specific * {@link org.springframework.transaction.PlatformTransactionManager} * bean definition. */String value() default "";/** * The transaction propagation type. * Defaults to {@link Propagation#REQUIRED}. * @see org.springframework.transaction.interceptor.TransactionAttribute#getPropagationBehavior() */Propagation propagation() default Propagation.REQUIRED;/** * The transaction isolation level. * Defaults to {@link Isolation#DEFAULT}. * @see org.springframework.transaction.interceptor.TransactionAttribute#getIsolationLevel() */Isolation isolation() default Isolation.DEFAULT;/** * The timeout for this transaction. * Defaults to the default timeout of the underlying transaction system. * @see org.springframework.transaction.interceptor.TransactionAttribute#getTimeout() */int timeout() default TransactionDefinition.TIMEOUT_DEFAULT;/** * {@code true} if the transaction is read-only. * Defaults to {@code false}. * <p>This just serves as a hint for the actual transaction subsystem; * it will <i>not necessarily</i> cause failure of write access attempts. * A transaction manager which cannot interpret the read-only hint will * <i>not</i> throw an exception when asked for a read-only transaction. * @see org.springframework.transaction.interceptor.TransactionAttribute#isReadOnly() */boolean readOnly() default false;/** * Defines zero (0) or more exception {@link Class classes}, which must be a * subclass of {@link Throwable}, indicating which exception types must cause * a transaction rollback. * <p>This is the preferred way to construct a rollback rule, matching the * exception class and subclasses. * <p>Similar to {@link org.springframework.transaction.interceptor.RollbackRuleAttribute#RollbackRuleAttribute(Class clazz)} */Class<? extends Throwable>[] rollbackFor() default {};/** * Defines zero (0) or more exception names (for exceptions which must be a * subclass of {@link Throwable}), indicating which exception types must cause * a transaction rollback. * <p>This can be a substring, with no wildcard support at present. * A value of "ServletException" would match * {@link javax.servlet.ServletException} and subclasses, for example. * <p><b>NB: </b>Consider carefully how specific the pattern is, and whether * to include package information (which isn't mandatory). For example, * "Exception" will match nearly anything, and will probably hide other rules. * "java.lang.Exception" would be correct if "Exception" was meant to define * a rule for all checked exceptions. With more unusual {@link Exception} * names such as "BaseBusinessException" there is no need to use a FQN. * <p>Similar to {@link org.springframework.transaction.interceptor.RollbackRuleAttribute#RollbackRuleAttribute(String exceptionName)} */String[] rollbackForClassName() default {};/** * Defines zero (0) or more exception {@link Class Classes}, which must be a * subclass of {@link Throwable}, indicating which exception types must <b>not</b> * cause a transaction rollback. * <p>This is the preferred way to construct a rollback rule, matching the * exception class and subclasses. * <p>Similar to {@link org.springframework.transaction.interceptor.NoRollbackRuleAttribute#NoRollbackRuleAttribute(Class clazz)} */Class<? extends Throwable>[] noRollbackFor() default {};/** * Defines zero (0) or more exception names (for exceptions which must be a * subclass of {@link Throwable}) indicating which exception types must <b>not</b> * cause a transaction rollback. * <p>See the description of {@link #rollbackForClassName()} for more info on how * the specified names are treated. * <p>Similar to {@link org.springframework.transaction.interceptor.NoRollbackRuleAttribute#NoRollbackRuleAttribute(String exceptionName)} */String[] noRollbackForClassName() default {};} 基于源代码，我们可以发现在@Transactional，原来有这么多的属性可以进行配置，从而达到复杂应用控制的目的。具体各个属性的用法和作用，将在本文的后面逐一进行讲解和说明。
2. 使用@Transactional的Spring配置
若不给自己设限，则人生中就没有限制你发挥的藩篱。
