login_1.java

在线判作业系统

package teachmanage.Servlets;

//import teachmanage.Student_management.Stu_management;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import teachmanage.DB_management.DBbean;
import javax.sql.*;
import java.sql.*;
import teachmanage.Student_management.Stu_management;

public class login_1 extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";

    //Initialize global variables
    public void init() throws ServletException {
    }

    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        DBbean myDB = new DBbean();
        String radio="";
        String user="";
        String pwd="";
        String name="";
        String sql="";
        String message="";
        ResultSet rs =null;
        String errorPage = response.encodeRedirectURL("error.jsp");
        radio = request.getParameter("RadioGroup1");
        System.out.println(radio);
        user = request.getParameter("user");
        request.getSession().setAttribute("user",user);
        pwd = request.getParameter("pwd");

        if(radio.equals("3"))
       {
           sql = "select * from Manager where Mno='" + user + "'and Mpwd='" + pwd+"'";
           try
           {
               rs = myDB.executeSelect(sql);
               if(rs.next())
               {
                   name = rs.getString("Mname");
               }
               System.out.println(name);
               request.setAttribute("name",name);
           }catch(SQLException e){
                   e.getStackTrace();
           }
           if(!rs.equals(null))
           {
               String url = response.encodeRedirectURL("manager.jsp");
               request.getRequestDispatcher(url).forward(request,response);
           }
           else {

               request.getRequestDispatcher(errorPage).forward(request,response);
           }
       }
       if(radio.equals("2"))
       {
           sql = "select * from Teacher where Tno = " + user + "and Tpwd=" +pwd;
           try
           {
               rs = myDB.executeSelect(sql);
               while(rs.next())
               {
                   name = rs.getString("Tname");
                   System.out.println(name);
               }
              request.setAttribute("name",name);
          }catch(SQLException e){
                  e.getStackTrace();
          }
           if(rs!=null)
           {
               String url = response.encodeRedirectURL("");
               request.getRequestDispatcher(url).forward(request,response);
           }
       }
       if(radio.equals("1"))
       {
           sql = "select * from Student where Sno = " + user + "and Spwd=" + pwd;
           try
           {
               rs = myDB.executeSelect(sql);
               if(rs.next())
               {
                   name = rs.getString("Sname");
               }
               request.setAttribute("name",name);
           }catch(SQLException e){
                   e.getStackTrace();
           }
          if(rs!=null)
          {

              String url = response.encodeRedirectURL("showstuinfo.jsp");
              request.getRequestDispatcher(url).forward(request,response);
          }
          else
              response.sendRedirect(errorPage);
       }
    }

    //Clean up resources
    public void destroy() {
    }
}