项目注册模块有个验证用户名是否存在，然后突然报错，下面是报错信息
Written [{"error_msg":"nested exception is org.apache.ibatis.exceptions.PersistenceException: \r\n### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Io 异常: The Network Adapter could not establish the connection)\r\n### The error may exist in com/neusoft/resume/userinfo/mapper/UserInfoMapper.xml\r\n### The error may involve com.neusoft.resume.userinfo.dao.IUserInfoDao.checkUsernameExist\r\n### The error occurred while executing a query\r\n### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Io 异常: The Network Adapter could not establish the connection)","error_num":1000}] as "application/json" using [org.springframework.http.converter.StringHttpMessageConverter@1ad6884]
数据库问题已自行解决
无法建立连接，UserInfoMapper.xml，这个配置文件没写对咯
UserInfoMapper.xml配置文件出问题或者om.neusoft.resume.userinfo.dao.IUserInfoDao.checkUsernameExist方法错了
这个怎么解决的 ？是数据库设置有问题 ？我遇到远程连数据库 出现这种问题