log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:
The last packet successfully received from the server was 11,979 milliseconds ago. The last packet sent successfully to the server was 11,969 milliseconds ago.
The last packet successfully received from the server was 11,979 milliseconds ago. The last packet sent successfully to the server was 11,969 milliseconds ago.
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:149)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:76)
at test.MybatisTest.main(MybatisTest.java:29)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 11,979 milliseconds ago. The last packet sent successfully to the server was 11,969 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl
The error may exist in pojo/CustomerMapper.xml
The error may involve pojo.Customer.findCustomerById
The error occurred while executing a query
Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
看下提示的地方findCustomerById
你先测试一下数据库驱动，是否能和数据库建立连接
Communications link failure，数据库连接失败，请检查mysql是否正常启动。