readerlogincontroller.java

学习jsp时做的一个书馆

 import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import library.DBConnection;
import library.Reader;
@SuppressWarnings("serial")
public class ReaderLoginController  extends Controller {
	 public void doPost (HttpServletRequest req,
				HttpServletResponse res) throws ServletException, IOException {
		
		String pass=null, uname=null;

		HttpSession session = req.getSession();
		
		pass = req.getParameter("rdpasswd");
		uname = req.getParameter("readerID");
		
		session.invalidate();
		
		session = req.getSession();
		
	    boolean islogin = true;
	    boolean isgs =true;
	    boolean isqianfei = true;
	    boolean isguoqi = true;
		try {

    	    DBConnection myConnection = DBConnection.Instance();
    		String sqlQuery ="select * from reader where ReaderID='" + uname +"' and password = '"+pass+ "'";
    		ResultSet r = null;
    		
    		r = myConnection.runQuery( sqlQuery );
    		if (r.next()){
              islogin = false;
    		}
    		 sqlQuery = "select findid,redata,TO_DAYS(NOW())-TO_DAYS(redata) as sum from bookhavebr where TO_DAYS(redata)-TO_DAYS(NOW())<0 and readerid ='"+uname+"'";
    		 r = myConnection.runQuery( sqlQuery );
    		 if(r.next()){
    			 isqianfei=false;
    		 }
    		 sqlQuery = "select * from guashi where readerid = '"+uname+"'";
    		 r = myConnection.runQuery( sqlQuery );
    		 if(r.next()){
    			isgs=false;
    		 }
    		 
    		 sqlQuery = "select TO_DAYS(NOW())-TO_DAYS(usedata) as sum from reader where readerid = '"+uname+"'";
    		 r = myConnection.runQuery( sqlQuery );
    		 int  day = 0;
    		 while(r.next()){
    			 day = Integer.parseInt(r.getString("sum"));
    		 }
    		 
    		 if(day>0){
    			 isguoqi = false;
    		 }
		} catch (Exception e) {
			sendErrorRedirect(req, res, e);
		}
		
		
		/*
			sql = "select findid,redata,TO_DAYS(NOW())-TO_DAYS(redata) as sum from bookhavebr where TO_DAYS(redata)-TO_DAYS(NOW())<0 and readerid ='"+uname+"'";
			
			while(w.next()){
				String findid = w.getString("findid");
				String redata = w.getString("redata");
				double fakuan = Integer.parseInt(w.getString("sum"))*0.1;
				
				ResultSet v = null;
				sql  = "insert into fakuan (findid,readerid,days,fakuan) values " +
						"('"+findid+"','"+uname+"',"+Integer.parseInt(w.getString("sum"))+","+fakuan+")";
				//res.sendRedirect("../test.jsp?jieguo="+sql);
			    boolean rs=stmt.execute(sql);
			}*/
		try {
			if(islogin==true){
				 res.sendRedirect("../readerlogin.jsp?errMsg=cuowu");
			}else if(isqianfei==false&&isgs == true){
				DBConnection myConnection = DBConnection.Instance();
				String sql = "select findid,redata,TO_DAYS(NOW())-TO_DAYS(redata) as sum from bookhavebr where TO_DAYS(redata)-TO_DAYS(NOW())<0 and readerid ='"+uname+"'";
				ResultSet v = null;
				v =  myConnection.runQuery(sql);
			    String url ="jdbc:mysql://localhost/library?user=root&password=linux&useUnicode=true&characterEncoding=GB2312" ;
				Connection conn= DriverManager.getConnection(url); 
				Statement stmt=conn.createStatement();
				if(v.next()){
					String st="delete from fakuan where readerid= '"+uname+"'";
					boolean r = stmt.execute("delete from fakuan where readerid= '"+uname+"'");
				}
				v =  myConnection.runQuery(sql);
				while(v.next()){
					String findid = v.getString("findid");
					String redata = v.getString("redata");
					double fakuan = Integer.parseInt(v.getString("sum"))*0.1;
					
					String sql1  = "insert into fakuan (findid,readerid,days,fakuan) values " +
							"('"+findid+"','"+uname+"',"+Integer.parseInt(v.getString("sum"))+","+fakuan+")";
				    boolean rs=stmt.execute(sql1);
				}
				
				String st3 = "update bookhavebr set xujie = 0 where readerid = '"+uname+"'";
				boolean rs1 = stmt.execute(st3);
				session.setAttribute("rdlogin", "yes");
			    session.setAttribute("readerno", uname);
			    res.sendRedirect("../welcome.jsp");
			    
	     	}else if(isguoqi == false){	
			   res.sendRedirect("../readerlogin.jsp?errMsg=guoqi");
		    } else if(isgs == false){	
			   res.sendRedirect("../readerlogin.jsp?errMsg=guashi");
		    }else if (islogin == false) {
			    session.setAttribute("rdlogin", "yes");
			    session.setAttribute("readerno", uname);
			    res.sendRedirect("../welcome.jsp");
		    } 
		} catch (Exception e2) {
		    sendErrorRedirect(req, res, e2);
		}
	    }
}