idea 中web项目 用自带tomcat启动问题，

严重: Exception sending context initialized event to listener instance of class com.zenointel.logserver.util.WebAppContextListener
org.springframework.jdbc.UncategorizedSQLException: SqlMapClient operation; uncategorized SQLException for SQL []; SQL state [null]; error code [0];
--- The error occurred in com/zenointel/logserver/dao/configdb/ConfigDB.xml.
--- The error occurred while executing query.
--- Check the select * from ltsservice.serviceconfig where id>1 .
--- Check the SQL Statement (preparation failed).
--- Cause: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'; nested exception is com.ibatis.common.jdbc.exception.NestedSQLException:
--- The error occurred in com/zenointel/logserver/dao/configdb/ConfigDB.xml.
--- The error occurred while executing query.
--- Check the select * from ltsservice.serviceconfig where id>1 .
--- Check the SQL Statement (preparation failed).
--- Cause: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
at org.springframework.jdbc.support.SQLStateSQLExceptionTranslator.translate(SQLStateSQLExceptionTranslator.java:124)
at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.translate(SQLErrorCodeSQLExceptionTranslator.java:322)
at org.springframework.orm.ibatis.SqlMapClientTemplate.execute(SqlMapClientTemplate.java:212)
at org.springframework.orm.ibatis.SqlMapClientTemplate.executeWithListResult(SqlMapClientTemplate.java:249)
at org.springframework.orm.ibatis.SqlMapClientTemplate.queryForList(SqlMapClientTemplate.java:296)
at com.zenointel.logserver.dao.configdb.ConfigDBDaoImp.getServicesInfo(ConfigDBDaoImp.java:55)
at com.zenointel.logserver.dao.configdb.ConfigDBDaoImp.initDB(ConfigDBDaoImp.java:179)
at com.zenointel.logserver.util.WebAppContextListener.contextInitialized(WebAppContextListener.java:27)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4992)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5490)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1763)

Caused by: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'

原因：自己推测，用idea 启动web项目时，会生成 一个artifacts 文件，此文件中也有一个web.xml ,而idea会去部署这个artifacts,就会导致这个错误；

解决方法：删除artifacts 中的web.xml ,就解决了这个问题；