为MySql的数据库读取文件，可设数据库用户名及密码，默认为用户：root,密码:sa.可从ResultSet或statment开始读取-MySql database to read documents can be installed database user name and password, the default for users : root, Password : sa. ResultSet or from the statement reads

Connection的代理类，Statement的代理类，ResultSet的代理类.-Connection agent category, Statement of Acting categories, ResultSet agent category.

HashTable实例 public class HashTable_msg { public HashTable_msg() { String sum_sql="select mobilenum,count(*) from SJSJ_Msg where (left(in_date,6)=(select left(CONVERT(varchar(12) , getdate(), 112 ),6)))group by mobilenum" Hashtable<