Java基本知识之二

1.  系统登录报错： connection holder is null

try(Connection connection= getConnection()){ 

 try(PreparedStatement psts = connection.prepareStatement("SELECT F01 FROM S71.T7101 WHERE F02 = ?)")){
                 psts.setInt(1, 111);
                 try(ResultSet resultSet = psts.executeQuery()){
                     if(resultSet.next()){
                        
                     }
            }      
            }

}

数据源切换到C3P0

Connection  PreparedStatement   ResultSet 加try