一、login.jsp登陆界面实现
解压bootmetro-master.zip，然后将\bootmetro-master\src\下的assets目录复制到project里。
bootmetro下载地址：https://github.com/aozora/bootmetro，使用说明：http://www.guoxiaoming.com/bootmetro/
创建head.jsp文件。用于将一些药固定引用的css、js文件放到这里。作为公共调用文件。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head> <link rel="stylesheet" type="text/css" href="assets/css/bootmetro.css">
<link rel="stylesheet" type="text/css" href="assets/css/bootmetro-responsive.css">
<link rel="stylesheet" type="text/css" href="assets/css/bootmetro-icons.css">
<link rel="stylesheet" type="text/css" href="assets/css/bootmetro-ui-light.css">
<link rel="stylesheet" type="text/css" href="assets/css/datepicker.css"> <!-- these two css are to use only for documentation -->
<link rel="stylesheet" type="text/css" href="assets/css/site.css"> <!-- Le fav and touch icons -->
<link rel="shortcut icon" href="assets/ico/favicon.ico">
<link rel="apple-touch-icon-precomposed" sizes="144x144" href="assets/ico/apple-touch-icon-144-precomposed.png">
<link rel="apple-touch-icon-precomposed" sizes="114x114" href="assets/ico/apple-touch-icon-114-precomposed.png">
<link rel="apple-touch-icon-precomposed" sizes="72x72" href="assets/ico/apple-touch-icon-72-precomposed.png">
<link rel="apple-touch-icon-precomposed" href="assets/ico/apple-touch-icon-57-precomposed.png"> <!-- All JavaScript at the bottom, except for Modernizr and Respond.
Modernizr enables HTML5 elements & feature detects; Respond is a polyfill for min/max-width CSS3 Media Queries
For optimal performance, use a custom Modernizr build: www.modernizr.com/download/ -->
<script src="assets/js/modernizr-2.6.2.min.js"></script> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title>
</head> </html>
创建login.jsp文件：
<%@ include file="head.jsp"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%> <body style="text-align:center;margin-bottom:100px;">
<div class="navbar" >
<div class="navbar-inner">
<a class="brand" href="#" style="margin-left:200px;">网盘</a> </div>
</div>
<div style="text-align:left;margin:0px auto;margin-top:50px; width:1200px;height:500px;">
<div style="float:left;width:800px; height:100%;background:#009900"></div>
<div style="float:left;width:400px; height:100%; background:#00CC33">
<fieldset>
<form action="LoginServlet" method="post" class="form-horizontal" style="margin-top:150px;margin-left:100px;"> 用户 <input type="text" id="inputEmail" name="username" >
<br><br>
密码 <input type="password" id="inputPassword" name="password">
<br><br>
<button type="submit" class="btn">登陆</button>
<button type="submit" class="btn">注冊</button> </form>
</fieldset>
</div> </div> </body>
启动tomcatserver測试效果，想要很多其它绚丽的小姑。大家能够自己去实现。（这里还无法实现登陆）
二、连接数据库
（1）将mysql-connector-java-commercial-5.1.25.jar拷贝到/WEB-INF/lib文件夹下。
（2）创建user表和加入数据
打开navicat for mysql 软件。连接hadoop数据库并创建user表，然后向表里加入3个数据。
三、创建操作数据库的model文件
（1）ConnDB.java
package com.model; import java.sql.Connection;
import java.sql.DriverManager; public class ConnDB {
private Connection ct = null;
public Connection getConn(){ try {
//载入驱动
Class.forName("com.mysql.jdbc.Driver"); //得到连接
ct = DriverManager.getConnection("jdbc:mysql://localhost:3306/hadoop?user=root&password=");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} return ct;
}
}
（2）UserBean.java
package com.model;
public class UserBean {
String id;
String username;
String email;
String password;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
（3）UserBeanCl.java
package com.model; import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement; public class UserBeanCl {
private Statement sm = null;
private Connection ct = null;
private ResultSet rs = null; public void close(){
try { if(sm != null){
sm.close();
sm = null;
} if(ct != null){
ct.close();
ct = null;
} if(rs != null){
rs.close();
rs = null;
} }
catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} //检查登录用户是否合法
public boolean checkUser(String user, String password){
boolean b = false;
try { //获得连接
ct = new ConnDB().getConn();
//创建statement
sm = ct.createStatement(); rs = sm.executeQuery("select * from user where username=\""+user+"\""); if(rs.next()){
//说明用户存在
String pwd = rs.getString(3);
if(password.equals(pwd)){
//说明密码正确
b = true;
}else{
b = false;
} }else{
b = false;
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
this.close();
} return b;
} }
（3）创建LoginServlet文件处理登陆的用户
package com.controller; import java.io.IOException; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession; import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.mapred.JobConf; import com.model.*; /**
* Servlet implementation class ListServlet
*/
public class LoginServlet extends HttpServlet { /**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
} /**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username");
String password = request.getParameter("password"); UserBeanCl ubc = new UserBeanCl();
if(ubc.checkUser(username, password)){
//用户合法。跳转到界面
HttpSession session = request.getSession();
session.setAttribute("username", username); JobConf conf = HdfsDAO.config();
HdfsDAO hdfs = new HdfsDAO(conf);
FileStatus[] list = hdfs.ls("/"+username);
request.setAttribute("list",list);
request.getRequestDispatcher("index.jsp").forward(request, response);
}else{
//用户不合法。调回登录界面，并提示错误信息
request.getRequestDispatcher("login.jsp").forward(request, response);
} } }
（4）重新启动tomcatserver測试，这次就能够实现用户登陆页面跳转了（从login.jsp跳转到index.jsp）