checkinvidservlet.java

该系统具体分为2个部分：前台和后台。 1．前台主要用于用户进行浏览和搜索

package ynuServlet;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.sql.*;
import java.sql.SQLException;
import ynuBean.ConnectDataBase;

public class CheckInvidServlet extends HttpServlet{
	private static final String CONTENT_TYPE = "text/html; charset=GBK";
	
	public void init()throws ServletException
    {
    	
    }
    
    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
    	sendsql(request,response);
    }
    
    public void sendsql(HttpServletRequest request, HttpServletResponse response)
    throws ServletException,IOException
    {
    	HttpSession session = request.getSession();   	
    	
    	String userName = request.getParameter("username");
    	String password = request.getParameter("pwd");
        	
    	if(userName!=null&& !userName.equals(""))
    	{
    		userName = new String(userName.getBytes("ISO-8859-1"),"UTF-8");
    		executeSql(request,response,userName,password);
    	}
    	else
    	{
    		session.invalidate();
    	}

    }
	
    public void executeSql(HttpServletRequest request, HttpServletResponse response,String userName,String password)
                  throws ServletException,IOException 
    {
       String toJsp = "/adminindex.jsp";
       try{
       	    ConnectDataBase aConnect = new ConnectDataBase();
		    Connection con = aConnect.getconnection();
		    Statement sqlstatement = con.createStatement(); 
            String sql = "select * from login where username='"+userName+"'";
    	    sql += "and password='"+ password+"'";
    	    ResultSet rs=sqlstatement.executeQuery(sql);
    	    
    	    /*while(rs.next())
    	    {
    	    	userid = rs.getInt("UserId");
    	    }*/
    	    response.setContentType("text/html");
    	    HttpSession session = request.getSession();
    	    ServletContext servletContext = getServletContext();
    	    
    	    if(rs.next()){
    	    	String name = rs.getString("username");
    	    	String pwd = rs.getString("password");
    	    	String role = rs.getString("role");
    	    	
    	    	if(role.equals("admin"))
    	    	{
    	    		toJsp = "/adminindex.jsp";
    	    		session.setAttribute("username",name);
        	    	session.setAttribute("password",pwd);
    	    	}
    	    	else if(role.equals("user"))
    	    	{
    	    		toJsp = "/uindex.jsp";
    	    		session.setAttribute("username",name);
    	    		
    	    	}
    	    }
    	    else{
    	    	session.setAttribute("errInf","用户名与密码不匹配");
    		    toJsp="/index.jsp";
    	    }
    	    con.close(); 
    	}catch (SQLException e) {
      		System.out.println(e.toString());
    	}
    	catch (Exception e) {
    		System.out.println(e.toString());
    	} 
    	
    	RequestDispatcher dispatcher = request.getRequestDispatcher(toJsp);	
    	//dispatcher = request.getRequestDispatcher(toJsp);   	
    	response.setHeader("Refresh", "0.1; URL=/PesticideInfoManagement"+toJsp+"");
    	dispatcher.forward(request, response);
    }	
    
    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        doGet(request, response);
    }
}