jieguacontroller.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;


public class jieguaController   extends Controller {
	 @SuppressWarnings("unchecked")
		public void doPost (HttpServletRequest req,
					HttpServletResponse res) throws ServletException, IOException {
			HttpSession session = req.getSession();
			//req.setCharacterEncoding("GB2312"); 
			
			String id =  new String(req.getParameter("readerid").getBytes("ISO-8859-1"),"GB2312");
			String passwd =  new String(req.getParameter("passwd").getBytes("ISO-8859-1"),"GB2312");
			session = req.getSession();
		
			boolean find = true;
			boolean find2 = true;
			boolean find3 = true;
			
			if(id.equals("")){
				    find = false;
			}
			try{
				String sql = "select * from guashi where readerid = '"+id+"'";
				DBConnection connection = DBConnection.Instance();
				ResultSet w = null;
			    w = connection.runQuery(sql);
			    if(!w.next()){
			    	find2 = false;
			    }
			    sql = "select password from reader where readerid = '"+id+"'";
			    w = connection.runQuery(sql);
			    while(w.next()){
			    	if(!passwd.equals(w.getString("password"))){
			    		find3 = false;
			    	}
			    }
			}catch(Exception e1){
				 sendErrorRedirect(req, res, e1);
			}
			try{
				if(find==false){
					res.sendRedirect("../admin/jiegua.jsp?jieguo=failed1");
				}else if(find2 == false){
					res.sendRedirect("../admin/jiegua.jsp?jieguo=failed2");
				}else if(find3 == false){
					res.sendRedirect("../admin/jiegua.jsp?jieguo=failed3");
				}else{
					String sql = "delete from guashi where readerid = '"+id+"'";
					  String url ="jdbc:mysql://localhost/library?user=root&password=linux&useUnicode=true&characterEncoding=GB2312" ;
					    Connection conn= DriverManager.getConnection(url); 
					    Statement stmt=conn.createStatement();
					    boolean rs=stmt.execute(sql);
					res.sendRedirect("../admin/jiegua.jsp?jieguo=success");
					//res.sendRedirect("../test.jsp?jieguo="+sql);
				}
				
			}catch(Exception e){
				 sendErrorRedirect(req, res, e);
			}
		 }
	}