No transactional EntityManager available; nested exception is javax.persistence.TransactionRequiredException: No transactional EntityManager available

参考地址:
http://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/config/EnableJpaRepositories.html#enableDefaultTransactions--
public abstract boolean enableDefaultTransactions

Configures whether to enable default transactions for Spring Data JPA repositories. Defaults to true. If disabled, repositories must be used behind a facade that's configuring transactions (e.g. using Spring's annotation driven transaction facilities) or repository methods have to be used to demarcate transactions.

Returns:

whether to enable default transactions, defaults to true.

Default:

true

原来是在spring配置文件中关闭了jpa默认的事务管理机制

<jpa:repositories base-package="com.xx.order"
		enable-default-transactions="false" />

　需要手动开启，所以，用spring的annotation在方法或类里面开启------------------(用@Transactional)