</frameset>

      <frameset rows="*,119" cols="*" framespacing="0" frameborder="yes">

      <frame src="leave.jsp" frameborder="1" scrolling="no" noresize="noresize">

      </frameset>

</frameset>

　　教师还可将自己知道的一些好的网站添加到网站里，把友情链接的网名和网址添加进去，学生会在页面上看见添加进的网站名字，用户可以点网站名进入相应的网站。

　　为了方便管理和安全，将所有的sql语句都封装在一个Sql类中，并且每条语句都定义成public static final类的，这样就不允许有别的语句继承它们。具体的代码如下：

public final class Sql {

      //用户登录

      public static final String login_tb_user = "select count(*) from tb_user where user_name=? and user_password=?";

      //用户注册向数库数中增加数据

      public static final String registAdd_tb_user ="insert into tb_user (user_name,user_password,realname,email)" +"values(    ?,          ?,           ?,         ?  )";

//    public static final String queryId_tb_user ="select user_id from tb_user where user_name=?";

      public static final String registCheck_tb_user="select count(*) from tb_user where user_name=?";

      public static final String add_tb_articleType="insert into tb_articleType (typeName,description) values(?,?)";

      public static final String query_tb_articleType="select * from tb_articleType";

      public static final String del_tb_articleType="delete from tb_articleType where type_id=?";

      public static final String add_tb_article="insert into tb_article (title,type_id,content,phTime,number) values(?,?,?,?,?)";

      public static final String del_tb_article="delete from tb_article where article_id=?";

      public static final String query_Article="select * from tb_article";

      public static final String show_Article="select tb_article.*,tb_articleType.* from tb_article,tb_articleType where (tb_article.type_id=tb_articleType.type_id and tb_article.type_id=? and article_id=?)";

      public static final String xin="select tb_article.*,typeName,description  from tb_article left join tb_articleType on (tb_article.type_id=tb_articleType.type_id)";

      public static final String add_tb_note="insert into tb_note (note_title,note_content,note_time) values(?,?,?)";

    public static final String query_tb_note="select * from tb_note";

public static final String del_tb_note="delete from tb_note where note_id=?";

      public static final String show_tb_note="select * from tb_note where note_id=?";

      public static final String update_tb_note="update tb_note set note_content=? ,note_time=? where note_id=?";

      public static final String update_tb_article= "update tb_article set content=? ,phTime=? where article_id=?";

      public static final String query_tb_user = "select user_id,user_name,realname,email from tb_user";

public static final String del_tb_user = "delete from tb_user where user_id=?";

public static final String query_tb_message = "select *  from tb_message order by mes_id";

public static final String delone_tb_message = "delete from tb_message where mes_id=?";

public static final String delall_tb_message = "delete from tb_message";

public static final String reply_tb_message = "insert into tb_message (mes_content,mes_sender,mes_sendTime,to_whom) values(?,?,?,?,?)";

public static final String add_tb_link = "insert into tb_link (link_name,link_add) values (?,?)";

      public static final String del_tb_link = "delete from tb_link where link_id=?";

      public static final String query_tb_link = "select link_id,link_name,link_add from tb_link";

      //     public static final String part_Article = "select article_id,title,content,phTime,number from tb_article order by article_id desc";

      public static final String part_Article = "select article_id,title,content,phTime,number,typeName from tb_article left join tb_articleType on (tb_article.type_id=tb_articleType.type_id) order by article_id desc";

public static final String show_link = "select * from tb_link ";

      public static final String show_note = "select * from tb_note order by note_id desc";

public static final String add_tb_video = "insert into tb