a04c5e1d2287001d146e9d053166f5f1

一个相对比较简单的留言簿！功能还比较齐全！

package com.pure35.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//import javax.swing.JOptionPane;


import com.pure35.database.Dao;
import com.pure35.database.User;
import com.pure35.database.Database;


public class LoginC extends HttpServlet {
	
	Connection con=null;
	ResultSet rs=null;
	Statement sm=null;
	public void doPost(HttpServletRequest req, HttpServletResponse res)
	throws ServletException, IOException {
	
		String u=req.getParameter("username");
		String p=req.getParameter("password");
		Database db=new Database();
		con=db.connect();
		try {
			sm=con.createStatement();
		String sql="select top 1* from user where username="+u+"password="+p+"";
			rs=sm.executeQuery(sql);
			String dbu=rs.getString("username");
			String dbp=rs.getString("password");
			if(dbu.equals(u)&&dbp.equals(p)){
			
				req.getRequestDispatcher("success.jsp").forward(req, res);
			}
				
			/*if(rs.next())
			{
				PrintWriter out=res.getWriter();
				out.print("aaa");
				req.getRequestDispatcher("success.jsp").forward(req, res);
			}*/
			else{
				
				req.setAttribute("result", "该用户不存在！");
				req.getRequestDispatcher("Login.jsp").forward(req, res);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		finally{
			try {
				if(rs!=null)
				{
				
						rs.close();
				}
				if(sm!=null)
				{
				
						sm.close();
				}
				if(con!=null)
				{
				
						con.close();
				}
				
				
					} catch (SQLException e) {
						e.printStackTrace();
				}
		}
	}
		
		/*	//String domethod=req.getParameter("domethod");
		String str="该用户不存在";
		//if(domethod.equals("login")){
		
			boolean isLogin=false;
			
				try {
					isLogin=this.login(req,res);
				} catch (ClassNotFoundException e) {
					e.printStackTrace();
				}
				
		 if(isLogin)
		   {
			   req.getRequestDispatcher("success.jsp").forward(req, res);
		   }
		 else
		 {
			 
			 req.setAttribute("result", str);
			 //JOptionPane.showMessageDialog(null, str);
			 req.getRequestDispatcher("Login.jsp").forward(req, res);
		 }
		 
	}
	/**
	 * 
	 * 登陆
	 * @param request
	 * @param response
	 * @return
	 */
	/*public boolean login(HttpServletRequest req, HttpServletResponse res) throws ClassNotFoundException {
		//从页面获取提交的数据
		String n=req.getParameter("username");
		String p=req.getParameter("password");
		Dao dao=new Dao();
		User user=new User();
		//通过set方法设置user的属性，把页面获取的数据赋给user
		user.setUsername(n);
		user.setPassword(p);
		
		boolean bool= false;
		bool=dao.login(user);
		
		return bool;
	}
*/
	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {

	}
	public void destroy() {
		super.destroy(); 
	}

}