采用JSP+Servlet+JavaBean+JDBC方式开发一个Web登录程序

1. 目录

    

   DBConn.java

   login.jsp

   main.jsp

   error.jsp

   LoginServlet.java

   web.xml

   Login.java

   LoginDao.java

   ---

2. DBConn.java

   package org.db;
   import java.sql.*;
   public class DBConn {
   	public static Connection conn;//创建Connection连接对象conn
   	//已获取数据库连接
   	public static Connection getConn(){
   		try{
   			Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");//Class.forName方法加载注册SQL Server 2014的JDBC驱动
   			conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=MBOOK","sa","5678");//编写连接字符串conn,创建获取连接
   			return conn;
   		}catch(Exception e){
   			e.printStackTrace();
   			return null;
   		}
   	}
   	public static void CloseConn(){
   		try{
   			conn.close();//自带函数关闭连接
   		}catch(Exception e){
   			e.printStackTrace();
   		}
   	}
   }
   

    

3. login.jsp

   <%@page lanuage="java" pageEncoding="gb2312"%>
   
   
   
   
   
   	
   
   		
   用户登录
   		
   
   			
   登录名
   			
   
   		
   		
   
   			
   密码
   			
   		
   		
   	
   	
   

    

4. main.jsp

   <%@ page language="java" pageEncoding="gb2312" import="org.model.Login" %>
   
   
   	
   
   
   	<%
   		Login login=(Login)session.getAttribute("login");	//从会话中取出 Login 对象
   		String lgn=login.getName();							//通过 JavaBean 对象获取用户名
   	%>
   	<%=lgn%>，您好！欢迎使用图书管理系统。
   
   

    

5. error.jsp

   <%@ page language="java" pageEncoding="gb2312"%>
   
   
   	
   
   
   	登录失败！单击这里返回
   
   
   

    

6. LoginServlet.java

   /**
    * 
    */
   /**
    * @author 123
    *
    */
   package org.servlet;
   import java.io.*;
   import javax.servlet.*;
   import javax.servlet.http.*;
   import org.model.*;
   import org.dao.*;
   public class LoginServlet extends HttpServlet{
   	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
   		request.setCharacterEncoding("gb2312");
   		LoginDao loginDao = new LoginDao();
   		Login l= loginDao.checkLogin(request.getParameter("name"),request.getParameter("password"));
   		if(l!=null){
   			HttpSession session=request.getSession();
   			session.setAttribute("login", 1);
   			response.sendRedirect("main.jsp");
   		}else{
   			response.sendRedirect("error.jsp");
   		}
   	}
   	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
   		doGet(request,response);
   	}
   }

    

7. web.xml

   
   
     
     	loginServlet
     	org.servlet.LoginServlet
     
     
     	loginServlet
     	/loginServlet
     
   

    

8. Login.java

   /**
    * 
    */
   /**
    * @author 123
    *
    */
   package org.model;
   public class Login{
   	private Integer id;
   	private String name;
   	private String password;
   	private boolean role;
   	public Integer getId(){
   		return this.id;
   	}
   	public void setId(Integer id){
   		this.id=id;
   	}
   	public String getName(){
   		return this.name;
   	}
   	public void setName(String name){
   		this.name=name;
   	}
   	public String getPassword(){
   		return this.password;
   	}
   	public void setPassword(String password){
   		this.password=password;
   	}
   	public boolean getRole(){
   		return this.role;
   	}
   	public void setRole(boolean role){
   		this.role=role;
   	}
   }

    

9. LoginDao.java

   package org.dao;
   import java.sql.*;
   import org.model.*;
   import org.db.*;
   public class LoginDao{
   	Connection conn;
   	public Login checkLogin(String name, String password){
   		try{
   			conn=DBConn.getConn();
   			PreparedStatement pstmt = conn.prepareStatement("select * from [login] where name=?"+"and password=?");
   			pstmt.setString(1, name);
   			pstmt.setString(2, password);
   			ResultSet rs=pstmt.executeQuery();
   			if(rs.next()){
   				Login login=new Login();
   				login.setId(rs.getInt(1));
   				login.setName(rs.getString(2));//怎么分清这两个方法呢？
   				login.setPassword(rs.getString(3));
   				login.setRole(rs.getBoolean(4));
   				return login;
   			}
   			return null;
   		}catch(Exception e){
   			e.printStackTrace();
   			return null;
   		}finally{
   			DBConn.CloseConn();
   		}
   	}
   }