vote.java

这个是用jsp编写的投票系统代码

/*
 * Vote.java
 *
 * Created on 2008年6月5日, 下午5:29
 */

package myservlet;

import java.io.*;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.*;
import javax.servlet.http.*;
import mybean.DBBean;

/**
 *
 * @author Administrator
 * @version
 */
public class Vote extends HttpServlet {
    
    /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html;charset=gb2312");
        DBBean db=new DBBean();
        String id=request.getParameter("id");
        try {
            ResultSet rs=db.executeQuery("select count from vote where id="+id);
            int num=0;
            if(rs.next())  num=rs.getInt("count");
            num++;                   
            db.executeUpdate("update vote set count="+num+" where id="+id);
            rs.close();
            db.close();
            //RequestDispatcher rd=request.getRequestDispatcher("info.jsp");
            //rd.forward(request,response);
            response.sendRedirect("info.jsp");
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
        
    }
    
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Returns a short description of the servlet.
     */
    public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>
}