@Transactional如何在Spring项目中使用

@Target({ElementType.METHOD, ElementType.TYPE}) 
@Retention(RetentionPolicy.RUNTIME) 
@Inherited 
@Documented 
public @interface Transactional { 
 
  /** 
   * A qualifier value for the specified transaction. 
   * 
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}. 
   * 
This just serves as a hint for the actual transaction subsystem; 
   * it will not necessarily cause failure of write access attempts. 
   * A transaction manager which cannot interpret the read-only hint will 
   * not 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. 
   * 
This is the preferred way to construct a rollback rule, matching the 
   * exception class and subclasses. 
   * 
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. 
   * 
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. 
   * 
NB: 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. 
   * 
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 not 
   * cause a transaction rollback. 
   * 
This is the preferred way to construct a rollback rule, matching the 
   * exception class and subclasses. 
   * 
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 not 
   * cause a transaction rollback. 
   * 
See the description of {@link #rollbackForClassName()} for more info on how 
   * the specified names are treated. 
   * 
Similar to {@link org.springframework.transaction.interceptor.NoRollbackRuleAttribute#NoRollbackRuleAttribute(String exceptionName)} 
   */ 
  String[] noRollbackForClassName() default {}; 
 
} 

  PROPAGATION_REQUIRES_NEW : uses a completely independent transaction for
 each affected transaction scope. In that case, the underlying physical 
transactions are different and hence can commit or roll back independently, 
with an outer transaction not affected by an inner transaction's rollback status.

 ROPAGATION_NESTED : uses a single physical transaction with multiple 
savepoints that it can roll back to. Such partial rollbacks allow an
 inner transaction scope to trigger a rollback for its scope, with the outer 
transaction being able to continue the physical transaction despite some operations 
having been rolled back. This setting is typically mapped onto JDBC savepoints, so will 
only work with JDBC resource transactions.