mysql错误之一

iBatis org.apache.ibatis.transaction.TransactionException – Error configuring AutoCommit

最近发现用mybatis实现的登录功能，偶尔会爆出如下异常：

<pre class="brush:java prettyprint linenums">

1. org.apache.ibatis.exceptions.PersistenceException:

2. Error opening session. Cause: org.apache.ibatis.transaction.TransactionException: Error configuring AutoCommit.

3. Your driver may not support getAutoCommit() or setAutoCommit(). Requested setting: false.
4. Cause: com.mysql.jdbc.CommunicationsException:
5. Communications link failure due to underlying exception... ...

</pre>

多试几次以后，就又正常了，这个异常不是一直存在。不得其解，google 之，得到一种解决方案，不过他遇到的情况发生在mysql重启之时。

源地址： http://burtsev.net/en/2012/01/12/100

解决此问题，需要在mybatis(iBatis)的配置文件中加入两个属性：poolPingQuery 和 poolPingEnabled。具体如下：

<pre class="brush:xml prettyprint linenums">

1. <?xml version="1.0" encoding="UTF-8" ?>

2. <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">

3. <configuration>

4. <typeAliases>

5. ...

6. </typeAliases>

7. <environments default="development">

8. <environment id="development">

9. <transactionManager type="JDBC" />

10. <dataSource type="POOLED">

11. <property name="driver" value="${db.driver}" />

12. <property name="url" value="${db.url}" />

13. <property name="username" value="${db.user}" />

14. <property name="password" value="${db.password}" />

15. <property name="poolPingQuery" value="SELECT id FROM user WHERE id = 1" />

16. <property name="poolPingEnabled" value="true" />

17. </dataSource>

18. </environment>

19. </environments>

20. </configuration>

</pre>

其中SELECT id FROM user WHERE id = 1是查询配置中的数据库的某个表，这里是user表，推测这里可以配置成任意一个可以执行的sql语句，当然越简单越好。

http://cssor.com/ibatis-org-apache-ibatis-transaction-transactionexception-error-configuring-autocommit.html