Rollback in MyBatis using JDBC (no Spring, no containers) - mysql

Question

I've seen all sorts of posts on using Spring and MyBatis with transactions, but I'm facing a problem with rollbacks not working with plain old JDBC.
My ( test / throwaway) code is pretty simple : I open a session, insert a rec, throw an error on purpose and rollback the transaction. However, it always commits.
public static void main (String[] args){
//-- omitted for brevity
try {
org.apache.ibatis.logging.LogFactory.useSlf4jLogging();
inputStream = Resources.getResourceAsStream("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
sess = sqlSessionFactory.openSession(false);
BillsMapper mapper = sess.getMapper(BillsMapper.class);
BillState billState = new BillState();
billState.setBillId(-1);
billState.setLastName("TESTER");
billState.setFirstName("TESTER");
mapper.insert(billState);
logger.info("Post insert: key = {}", billState.getBillId());
if(1 == 1)
throw new RuntimeException("Error Thrown on purpose...testing rollback ");
sess.commit();
}catch(Exception e){
logger.error("Error: {}", e);
sess.rollback();
}finally{
sess.close();
logger.info("Finito!");
}
}
The logs show:
DEBUG | (BaseJdbcLogger.java:145) - ==> Preparing: insert into bills (users_userId, refId, firstName, ...
DEBUG | (BaseJdbcLogger.java:145) - ==> Parameters: 67(Integer), 67-120530180328(String), TESTER(String), ...
DEBUG | (BaseJdbcLogger.java:145) - <== Updates: 1
INFO | (TestAction.java:50) - Post insert: key = 2478
ERROR | (TestAction.java:56) - Error: {} java.lang.RuntimeException: Error Thrown on purpose...testing rollback at com.s2stest.TestAction.main(TestAction.java:53)
DEBUG | (JdbcTransaction.java:79) - Rolling back JDBC Connection [com.mysql.jdbc.JDBC4Connection#371e88fb]
DEBUG | (JdbcTransaction.java:122) - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection#371e88fb]
DEBUG | (JdbcTransaction.java:90) - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection#371e88fb]
DEBUG | (PooledDataSource.java:344) - Returned connection 924748027 to pool.
Note the resetting of autocommit before closing the connection.... Would resetting autcommit before closing the SqlSession cause my rolled-back transaction to be committed? If so, is this a bug? Has anyone gotten JDBC working with transactions? I need it for testing, and I'd value some help. Right now, no transactions can be rolled back.
I've looked at the MyBatis source, and it indeed calls resetAutocommit before closing the connection. I'm using MySQL 5.6 and mysql-connector-java-5.1.36.jar for the driver if someone has a workaround that they've found.
--- UPDATE ---
mybatis-config.xml is as follows:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="logImpl" value="SLF4J" />
</settings>
<typeAliases>
<package name="com.ship2storage.domain" />
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mytestDb?zeroDateTimeBehavior=convertToNull" />
<property name="username" value="--shhh!!--" />
<property name="password" value="--shhh!!--" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/ship2storage/db/maps/BillsMapper.xml" />
</mappers>
</configuration>

Answer 1

OK, I've found the answer by digging deeper into my setup. It seems that the MySQL storage engine I installed for my test DB is ISAM. ISAM does not support transactions. I switched to InnoDB using the following SQL tidbit, and transactions now work with JDBC:
ALTER TABLE bills ENGINE=InnoDB;
I haven't tried this, but it looks like you can also do this temporarily too:
SET default_storage_engine=InnoDB;
Hopefully this will help someone. The code/config posted above works.