附上日志：
DEBUG [main] - Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - Opening JDBC Connection
DEBUG [main] - Created connection 38544126.
DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@24c22fe]
DEBUG [main] - ==> Preparing: UPDATE N1 SET NAME=? WHERE ID=?
DEBUG [main] - ==> Parameters: xu(String), 1(Integer)
DEBUG [main] - <== Updates: 1
到这里就断了，什么原因？？？
尴尬，SqlSession忘记commit了