bg_message.java

用J2EE开发的网站,可以应用到图书馆,图书超市

package ksnb;
import java.sql.*;
import java.util.*;
import javax.servlet.http.*;
import java.text.*;
public class BG_Message {

    private conn c = null;
    private Connection con = null;
    private Statement stm = null;
    private ResultSet rs = null;
    private Collection ret = null;
    private String strSql=null;
    private int id=0 ;

    public BG_Message() {
        try {
            c = new conn();
            con = c.getConncetion();

        } catch (Exception e) {
            System.out.println(e.toString());
        }
        ret=new ArrayList();

    }
    private static String convert( String str )
   {
       try
       {
           byte[] bytesStr=str.getBytes( "ISO-8859-1" ) ;
           return new String( bytesStr, "gb2312" ) ;
       }
       catch( Exception ex)
       {
           return str ;
       }
   }

   public void Query(HttpServletRequest request)
   {
       id=Integer.parseInt((String)request.getParameter("Id"));
       System.out.println(id);
       strSql = "select * from Shop_Gbook_info where Product_id= '" + id +
                     "' order by Date_time desc";
            System.out.println(strSql);
       try {
            stm = con.createStatement();
            rs = stm.executeQuery(strSql);
            String Content = null;
            String Author = null;
            java.sql.Date date = null;
            int Book=0;
            int Id=0;


             while(rs.next())
               {
                   Id=rs.getInt("Id");
                   Book=rs.getInt("Product_id");
                   Content=rs.getString("Content");
                   Author=rs.getString("Author");
                   date=rs.getDate("Date_time");

                   MessageBean message=new MessageBean();
                   message.setId(Id);
                   message.setBook(Book);
                   message.setContent(Content);
                   message.setAuthor(Author);
                   message.setDatetime(date);

                   ret.add(message);

              }
              request.setAttribute("ret",ret);
              rs.close();
              stm.close();

        } catch(Exception e){System.out.println(e);}

   }
   public void Delete(HttpServletRequest request)
   {
       int Id=Integer.parseInt((String)request.getParameter("cmd1"));
       strSql="delete from Shop_Gbook_info where Id="+Id;
       System.out.println(strSql);
       try {
           stm = con.createStatement();
           stm.executeUpdate(strSql);
           stm.close();
       }
       catch(Exception e)
       {
           System.out.println(e.toString());
       }

   }




}