📄 votting.java

📁 一本jsp自学教材
💻 JAVA
字号:
package test;

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class Votting extends HttpServlet {
    DBConn conn=new DBConn();
    ResultSet rs1=null;
    ResultSet rs2=null;
    
    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {        
        response.setContentType("text/html;charset=GBK");
        PrintWriter out = response.getWriter();
        out.println("<html>");
        out.println("<head>");
	out.println("<title>投票失败</title>");
        out.println("</head>");
        out.println("<body bgcolor=\"white\">");
     try{
        String ip=request.getRemoteAddr();
        String topicid=request.getParameter("topicid");
        String pp=request.getParameter("p");
        int i=0;
        if(!HadVoted(ip))
          {
            String sql1="UPDATE votes SET result=result+1,ip=CONCAT(ip,'"+
                        ip+"','#') WHERE type>0 AND topicid="+topicid;
            conn.update(sql1);
            String sql3="UPDATE votes SET result=result+1 WHERE type=0 AND id="+pp;
            conn.update(sql3);
            response.sendRedirect("ListVotes");
          }
         else
          {
             out.print("<B>您已经投过票了！不能重复投票.</B><BR>"); 
             out.print("<B>IP:</B>"+ip); 
          }  
        }     
        catch(Exception e)
         {
             out.print(e.toString());
         }
        out.println("</body>");
        out.println("</html>");
    }
    public boolean HadVoted(String ip)
     {
       boolean flag=false;
       String sql2="SELECT * FROM votes WHERE ip REGEXP '#"+ip+"#'";
      try{
       rs2=conn.query(sql2);       
       if(rs2.next())
        flag=true;       
       rs2.close();      
      }
      catch(Exception ex)
       {
          System.out.print(ex.toString());
       }
       return flag;
     }
    public void doPost(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {  
      doGet(request,response);    
    }
   public void destroy()
    {
      conn=null;
      rs1=null;
      rs2=null;
    }
}
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