JavaWeb结合七牛云存储搭建个人相册

一、引言

1. 课程概述

相信很多人都知道网站一般会有很多图片，对于小型网站来说，图片放在网站服务器上不算什么，但当图片数量很大时，会造成服务器很臃肿，相应地对带宽要求也会提高，这就造成了成本的增加。其实现在已经流行云存储，我们可以把图片、大文件等放到第三方提供的云存储服务上，这会减少一部分成本。这门课程就介绍了JavaWeb结合七牛云存储来搭建个人相册服务。

2. 预备知识

掌握Servlet+JSP，能了解Bootstrap更好。

二、Just Do It!

项目开始前，你需要有一个七牛云存储的标准用户账号，新建一个Bucket，知道你自己的Access Key和Secret Key。

1. 创建数据库

这里我们使用MySQL数据库，创建名称为photo的数据库：

create database photo DEFAULT CHARSET=utf8;

CREATE TABLE `image` (  
`id` int(11) NOT NULL AUTO_INCREMENT,  
`name` varchar(16) DEFAULT NULL,  
`url` varchar(255) DEFAULT NULL,  
`date` datetime DEFAULT NULL,  
`user_id` int(11) DEFAULT NULL,  
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

CREATE TABLE `user` (  
`id` int(11) NOT NULL AUTO_INCREMENT,  
`username` varchar(16) DEFAULT NULL,  
`password` varchar(16) DEFAULT NULL,  
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

2. 创建JavaWeb项目

这里使用Eclipse创建一个名称为Photo的动态Web项目，加入Tomcat 7服务器，加入所需的jar包（源码中包含jar包），把Photo项目部署到Tomcat上。

3. 编写前端代码

前端使用Bootsrap，把css、fonts和js文件夹放到WebContent目录下。

创建index.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="zh-cn">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>实验楼个人相册</title>
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!--[if lt IE 9]>
      <script src="http://cdn.bootcss.com/html5shiv/3.7.2/html5shiv.min.js"></script>
      <script src="http://cdn.bootcss.com/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->
  </head>
  <body>
    <div class="container">
        <div class="row">
            <div class="col-xs-12 text-center">
                <h2>实验楼个人相册</h2>
            </div>
        </div>
        <div class="row">
            <div id="alert1"  class="alert alert-success fade in text-center col-xs-2 col-xs-offset-5 hide">
                <strong>注册成功</strong>
            </div>
        </div>
        <form id="form" class="form-horizontal" role="form" style="margin-top: 73px;">
          <div class="form-group"  >
            <label for="username" class="col-xs-2 control-label col-sm-offset-3" >用户名</label>
            <div class="col-xs-2">
              <input type="text" class="form-control" id="username" rel="tooltip"/>
            </div>
          </div>
          <div class="form-group">
            <label for="password" class="col-xs-2 control-label col-sm-offset-3">密码</label>
            <div class="col-xs-2">
              <input type="password" class="form-control" id="password"/>
            </div>
          </div>
          <div class="form-group">
            <div class="col-sm-offset-5 col-xs-1">
              <button type="button" class="btn btn-success" id="login">登录</button>
            </div>
            <div class="col-sm-1">
              <button type="button" class="btn btn-danger" data-toggle="modal" data-target="#myModal">注册</button>
            </div>
          </div>
        </form>
    </div>

    <!-- 注册对话框 begin -->
    <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
            <h4 class="modal-title" id="myModalLabel">用户注册</h4>
          </div>
          <div class="modal-body">
              <form class="form-horizontal" role="form">
              <div class="form-group"  >
                <label for="reg_username" class="col-xs-2 control-label" >用户名</label>
                <div class="col-xs-4">
                  <input type="text" class="form-control" id="reg_username"/>
                </div>
              </div>
              <div class="form-group">
                <label for="reg_password" class="col-xs-2 control-label">密码</label>
                <div class="col-xs-4">
                  <input type="password" class="form-control" id="reg_password"/>
                </div>
              </div>
              <div class="form-group">
                <label for="reg_repassword" class="col-xs-2 control-label">重复密码</label>
                <div class="col-xs-4">
                  <input type="password" class="form-control" id="reg_repassword"/>
                </div>
              </div>
            </form>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">取消</button>
            <button type="button" class="btn btn-primary" id="register">注册</button>
          </div>
        </div>
      </div>
    </div>
    <!-- 注册对话框 end -->

    <script src="http://cdn.bootcss.com/jquery/1.11.1/jquery.min.js"></script>
    <script src="js/bootstrap.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {     
          //点击登录
            $('#login').click(function() {    
             //提交登录表单
                $.post('${pageContext.request.contextPath}' + '/UserAction?type=1',
                {
                    username: $('#username').val(),
                    password: $('#password').val()
                },     
                function(data, status) {   
                    if (data == '1') {
                        createPopOver('#username', 'right', '用户名不能为空', 'show');
                    } else if (data == '2') {
                        createPopOver('#password', 'right', '密码不能为空', 'show');
                    } else if (data == '3') {
                        createPopOver('#username', 'right', '用户名不存在', 'show');
                    } else if (data == '4') {
                        createPopOver('#password', 'right', '密码错误', 'show');
                    } else if (data == 5) {
                        location.href = '${pageContext.request.contextPath}' + '/home.jsp';
                    }
                });
            });         

            //点击注册按钮
            $('#register').click(function() {    
                //提交注册表单
                $.post('${pageContext.request.contextPath}' + '/UserAction?type=2',
                {
                    username: $('#reg_username').val(),
                    password: $('#reg_password').val(),
                    repassword: $('#reg_repassword').val()
                },  
                function(data, status) { 
                    if (data == '1') {
                        createPopOver('#reg_username', 'right', '不能为空', 'show');
                    } else if (data == '2') {
                        createPopOver('#reg_password', 'right', '不能为空', 'show');
                    } else if (data == '3') {
                        createPopOver('#reg_repassword', 'right', '不能为空', 'show');
                    } else if (data == '4') {
                        createPopOver('#reg_repassword', 'right', '密码不一致', 'show');
                    } else if (data == '5') {
                        createPopOver('#reg_username', 'right', '用户名已存在', 'show');
                    } else if (data == '6') {
                        $('#reg_username').val('');
                        $('#reg_password').val('');
                        $('#reg_repassword').val('');
                        $('#myModal').modal('hide');
                        $('#alert1').removeClass('hide');
                        $('#form').css('margin-top', '0px');
                    }
                });
            }); 

            //显示弹出框
            function createPopOver(id, placement, content, action) {
                $(id).popover({
                    placement: placement,
                    content: content
                });
                $(id).popover(action);
            } 

           //点击输入框时销毁弹出框
            $('#username').click(function() {
                $('#username').popover('destroy');
            });

            $('#password').click(function() {
                $('#password').popover('destroy');
            });

            $('#reg_username').click(function() {
                $('#reg_username').popover('destroy');
            });

            $('#reg_password').click(function() {
                $('#reg_password').popover('destroy');
            });

            $('#reg_repassword').click(function() {
                $('#reg_repassword').popover('destroy');
            });
        }); 
   </script>
  </body>
</html>

创建home.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<!DOCTYPE html>
<html lang="zh-cn">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>${user.username}的个人相册</title>
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!--[if lt IE 9]>
      <script src="http://cdn.bootcss.com/html5shiv/3.7.2/html5shiv.min.js"></script>
      <script src="http://cdn.bootcss.com/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->
  </head>
  <body>
    <div class="container">
        <!-- 首部 start -->
        <div class="row">
            <div class="col-xs-8 col-xs-offset-2">
                <h3 class="page-header">
                    ${user.username}&nbsp;&nbsp;&nbsp;<small>共<span class="badge">${imageList.size()}</span>张</small>
                    <div class="btn-group pull-right">
                      <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
                          操作<span class="caret"></span>
                      </button>
                      <ul class="dropdown-menu" role="menu">
                        <li><a href="#" data-toggle="modal" data-target="#myModa2">上传</a></li>
                        <li><a href="#" data-toggle="modal" data-target="#myModa3">删除</a></li>
                        <li><a href="#" data-toggle="modal" data-target="#myModa4">退出</a></li>
                      </ul>
                    </div>
                </h3>
            </div>
        </div>
        <!-- 首部 end -->

        <!-- 显示图片列表 -->
        <c:forEach items="${imageList}" varStatus="status" var="image">
            <c:choose>
                <c:when test="${status.first or status.index % 4 eq 0}">
                    <div class="row">
                        <div class="col-xs-2 col-xs-offset-2">
                          <a href="#" class="thumbnail text-center">
                            <img name="${image.name}" date="<fmt:formatDate value='${image.date}' pattern='yyyy-MM-dd HH:mm'/>" style="width: 140px; height: 130px;" src="http://shiyanlouphoto.qiniudn.com/${image.url}">
                            <input class="pull-left" type="checkbox" value="${image.id}" url="${image.url}"/>${image.name } 
                           </a>
                        </div>
                </c:when>
                <c:when test="${status.index % 4 eq 3 and not status.last }">
                        <div class="col-xs-2">
                          <a href="#" class="thumbnail text-center">
                            <img name="${image.name}" date="<fmt:formatDate value='${image.date}' pattern='yyyy-MM-dd HH:mm'/>" style="width: 140px; height: 130px;" src="http://shiyanlouphoto.qiniudn.com/${image.url}">
                            <input class="pull-left" type="checkbox" value="${image.id}" url="${image.url}" />${image.name } 
                          </a>
                        </div>
                    </div>
                </c:when>
                <c:otherwise>
                    <div class="col-xs-2">
                      <a href="#" class="thumbnail text-center">
                        <img name="${image.name}" date="<fmt:formatDate value='${image.date}' pattern='yyyy-MM-dd HH:mm'/>" style="width: 140px; height: 130px;" src="http://shiyanlouphoto.qiniudn.com/${image.url}">
                        <input class="pull-left" type="checkbox" value="${image.id}" url="${image.url}"/>${image.name } 
                      </a>
                    </div>
                </c:otherwise>
            </c:choose>
            <c:if test="${status.last}">
                </div>
            </c:if>
        </c:forEach>
        <!-- 显示图片列表 end -->
    </div>

    <!-- 显示图片对话框 start -->
    <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            <h4 class="modal-title" id="myModalLabel"></h4>
          </div>
          <div class="modal-body" id="modal-content">
          </div>
        </div>
      </div>
    </div>
    <!-- 显示图片对话框 end -->

    <!-- 上传图片对话框 start -->
    <div class="modal fade" id="myModa2" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h4 class="modal-title" id="myModalLabe2">图片上传</h4>
          </div>
          <div class="modal-body">
              <form class="form-horizontal" role="form" id="form">
                <div class="form-group"  >
                <label for="image_name" class="col-xs-2 control-label" >名称</label>
                <div class="col-xs-4">
                  <input type="text" class="form-control" id="image_name" name="image_name"/>
                </div>
              </div>
              <div class="form-group">
                <label for="image" class="col-xs-2 control-label">图片</label>
                <div class="col-xs-4">
                    <input type="file" id="image" name="image"/>
                </div>
              </div>
            </form>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">取消</button>
            <button type="button" class="btn btn-primary" id="upload">上传</button>
          </div>
        </div>
      </div>
    </div>
    <!-- 上传图片对话框 end -->

    <!-- 删除图片对话框 start -->
    <div class="modal fade" id="myModa3" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h4 class="modal-title" id="myModalLabe3">确定删除吗？</h4>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">取消</button>
            <button type="button" class="btn btn-danger" id="delete">确定</button>
          </div>
        </div>
      </div>
    </div>
    <!-- 删除图片对话框 end -->

    <!-- 退出对话框 start -->
    <div class="modal fade" id="myModa4" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h4 class="modal-title" id="myModalLabe4">确定退出吗？</h4>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">取消</button>
            <button type="button" class="btn btn-danger" id="exit">确定</button>
          </div>
        </div>
      </div>
    </div>
    <!-- 退出对话框 end -->

    <script src="http://cdn.bootcss.com/jquery/1.11.1/jquery.min.js"></script>
    <script src="js/bootstrap.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            //点击图片
            $('img').click(function() {
                $('#myModalLabel').html($(this).attr('name') + '&nbsp;&nbsp;&nbsp;<small>' + $(this).attr('date') + '</small>');
                $('#modal-content').html('<img class=\'img-responsive\' src=\'' + $(this).attr('src') + '\'/>');
                $('#myModal').modal('show');
            }); 

           //点击上传
            $('#upload').click(function() {                if ($('#image_name').val() == '' || $('#image').val() == '') {
                } else {
                    $('#form').attr('action', '${pageContext.request.contextPath}' + '/ImageAction?type=1');
                    $('#form').attr('enctype', 'multipart/form-data');
                    $('#form').attr('method', 'post');
                    $('#form').submit();
                }
            }); 
           
            //点击确定退出
            $('#exit').click(function() {
                $.get('${pageContext.request.contextPath}' + '/UserAction?type=3', function(data, status) {
                    location.href = '${pageContext.request.contextPath}' + '/index.jsp';
                });
            }); 

           //点击确定删除图片
            $('#delete').click(function() { 
               var ids = ""; 
               var urls = "";
                $('input[type=checkbox]:checked').each(function() {
                    ids += $(this).val() + ',';
                    urls += $(this).attr('url') + ',';
                }); 
                $.post('${pageContext.request.contextPath}' + '/ImageAction?type=2', {
                    ids: ids,
                    urls: urls
                },function(data, status) {
                    $('#myModa3').modal('hide');
                    location.href = '${pageContext.request.contextPath}' + '/home.jsp';
                });
            });
        }); 
    </script>
  </body>
</html>

4. 编写后台代码

创建User类：

 * 用户类
 * @author www.shiyanlou.com
 *
 */
@SuppressWarnings("serial")
public class User implements Serializable { 
    private int id;    //用户ID
    private String username;    //用户名
    private String password;    //密码
    private List<Image> images;    //图片列表

    public User() {
    } 
    public User(int id, String username, String password, List<Image> images) { 
       this.id = id; 
       this.username = username; 
       this.password = password; 
       this.images = images;
    } 
 
    public User(String username, String password) { 
       this.username = username; 
       this.password = password;
    } 
  
    public User(int id) { 
       this.id = id;
    } 

    public List<Image> getImages() { 
       return images;
    } 

    public void setImages(List<Image> images) { 
       this.images = images;
    } 

    public int getId() { 
       return id;
    } 

    public void setId(int id) { 
       this.id = id;
    } 

    public String getUsername() { 
       return username;
    } 

    public void setUsername(String username) { 
       this.username = username;
    } 

    public String getPassword() { 
       return password;
    } 

    public void setPassword(String password) { 
       this.password = password;
    }

}

创建Image类：

/**
 * 图片类
 * @author www.shiyanlou.com
 *
 */@SuppressWarnings("serial")
public class Image implements Serializable { 
    private int id;    //图片ID
    private String name;    //图片名
    private String url;    //图片URL
    private Date date;    //上传时间
    private User user;    //所属用户

    public int getId() { 
       return id;
    } 

    public void setId(int id) { 
       this.id = id;
    } 

    public String getName() { 
       return name;
    } 

    public void setName(String name) { 
       this.name = name;
    } 

    public String getUrl() { 
       return url;
    } 

    public void setUrl(String url) { 
       this.url = url;
    } 

    public Date getDate() { 
       return date;
    }  

    public void setDate(Date date) {  
       this.date = date;
    } 

    public User getUser() { 
       return user;
    } 

    public void setUser(User user) { 
       this.user = user;
    }
}

创建数据库工具类：

/**
 * 数据库工具类
 * @author www.shiyanlou.com
 *
 */public class DBUtils { 
    private static Connection connection = null; 
    private static PreparedStatement preparedStatement = null; 
    private static ResultSet resultSet = null; 

    //初始化
    static { 
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (Exception e) {
            e.printStackTrace();
        }
    } 
 
    /**
     * 获取连接
     * @return
     */
    private static Connection getConnection() { 
        try {
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/photo?useUnicode=true&characterEncoding=UTF-8", "root", "root");
        } catch (SQLException e) {
            e.printStackTrace();
        }        return connection;
    } 

    /**
     * 关闭连接、预处理语句和结果集
     * @param connection
     * @param preparedStatement
     * @param resultSet
     */
    private static void close(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet) { 
        try { 
            if (resultSet != null) {
                resultSet.close();
                resultSet = null;
            } 

            if (preparedStatement != null) {
                preparedStatement.close();
                preparedStatement = null;
            }  

            if (connection != null) {
                connection.close();
                connection = null;
            }            
        } catch (Exception e) {
            e.printStackTrace();
        }
    } 

    /**
     * 查询数据库
     * @param sql SQL语句
     * @param parameters 参数
     * @return
     */
    public static ArrayList<Object[]> query(String sql, String[] parameters) {
        ArrayList<Object[]> list = new ArrayList<Object[]>(); 
        try {
            connection = getConnection();
            preparedStatement = connection.prepareStatement(sql); 
            for (int i = 0; i < parameters.length; i++) {
                preparedStatement.setString(i + 1, parameters[i]);
            }
            resultSet = preparedStatement.executeQuery(); 
            int columnCount = resultSet.getMetaData().getColumnCount(); 
            while (resultSet.next()) {
                Object[] objects = new Object[columnCount];  
                for (int i = 0; i < columnCount; i++) {
                    objects[i] = resultSet.getObject(i + 1);
                }
                list.add(objects);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            close(connection, preparedStatement, resultSet);
        } 
        return list;
    } 

    /**
     * 更新数据库
     * @param sqls SQL语句数组
     * @param parameters 参数数组
     */
    public static void updates(String[] sqls, String[][] parameters) { 
        try {
            connection = getConnection();
            connection.setAutoCommit(false); 
            for (int i = 0; i < sqls.length; i++) {
                preparedStatement = connection.prepareStatement(sqls[i]); 
                for (int j = 0; j < parameters[i].length; j++) {
                    preparedStatement.setString(j + 1, parameters[i][j]);
                }
                preparedStatement.executeUpdate();
            }
            connection.commit();
        } catch (Exception e) { 
            try {
                connection.rollback();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            e.printStackTrace();
        } finally {
            close(connection, preparedStatement, resultSet);
        }
    }
}

创建文件工具类（使用了七牛云存储服务）：

/**
 * 图片工具类（使用七牛云存储服务）
 * @author www.shiyanlou.com
 *
 */
public class FileUtils { 
    private static final String ACCESS_KEY = "你自己的Access Key"; 
    private static final String SECRET_KEY = "你自己的Secret Key"; 
    private static final String BUCKET_NAME = "创建的Bucket的名称"; 

    /**
     * 上传图片到七牛云存储
     * @param reader
     * @param fileName
     */
    public static void upload(InputStream reader, String fileName) {
        String uptoken; 
        try {
            Mac mac = new Mac(ACCESS_KEY, SECRET_KEY);
            PutPolicy putPolicy = new PutPolicy(BUCKET_NAME);
            uptoken = putPolicy.token(mac);
            IoApi.Put(uptoken, fileName, reader, null);
        } catch (AuthException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }    /**
     * 删除七牛云存储上的图片
     * @param key
     */
    public static void delete( String key) {
        Mac mac = new Mac(ACCESS_KEY, SECRET_KEY);
        RSClient client = new RSClient(mac);
        client.delete(BUCKET_NAME, key);
    }
}

创建用户服务类：

/**
 * 用户服务类
 * @author www.shiyanlou.com
 *
 */
public class UserService { 
    /**
     * 通过用户名获取用户
     * @param username 用户名
     * @return 用户
     */
    public User getUserByUsername(String username) {
        String sql = "select id, username, password from user where username = ?";
        String[] parameters = {username};
        List<Object[]> users = DBUtils.query(sql, parameters); 
        if (users.size() == 0) { 
            return null;
        } else {
            Object[] objects = users.get(0); 
            return objects == null ? null : new User(Integer.parseInt(objects[0].toString()), objects[1].toString(), objects[2].toString(), null);
        }
    } 

    /**
     * 添加用户
     * @param user 用户
     */
    public void addUser(User user) {
        String[] sqls = {"insert into user(username, password) values(?, ?)"};
        String[][] parameters = {{user.getUsername(), user.getPassword()}};
        DBUtils.updates(sqls, parameters);
    }
}

创建图片服务类：

/**
 * 图片服务类
 * @author www.shiyanlou.com
 *
 */
public class ImageService { 
    /**
     * 通过用户ID获取图片列表
     * @param userId 用户ID
     * @return 图片列表
     */
    public ArrayList<Image> getByUserId(int userId) {
        ArrayList<Image> images = new ArrayList<Image>();
        String sql = "select id, name, url, date, user_id from image where user_id = ? order by date desc";
        String[] parameters = {userId + ""};
        List<Object[]> imageList = DBUtils.query(sql, parameters); 
        for (Object[] objects : imageList) {
            Image image = new Image();
            image.setId(Integer.parseInt(objects[0].toString()));
            image.setName(objects[1].toString());
            image.setUrl(objects[2].toString());
            image.setDate((Date) objects[3]);
            image.setUser(new User(Integer.parseInt(objects[4].toString())));
            images.add(image);
        } 
        return images;
    } 
 
    /**
     * 上传图片
     * @param image 图片
     * @param inputStream 输入流
     */
    public void addImage(Image image, InputStream inputStream) {
        FileUtils.upload(inputStream, image.getUrl());
        String[] sqls = {"insert into image(name, url, date, user_id) values(?, ?, ?, ?)"};
        String[][] parameters = {{image.getName(), image.getUrl(), new SimpleDateFormat("yyyy-MM-dd HH:mm").format(image.getDate()), image.getUser().getId() + ""}};
        DBUtils.updates(sqls, parameters);
    } 

    /**
     * 通过图片ID数组和图片URL数组删除图片
     * @param ids 图片ID数组
     * @param urls 图片URL数组
     */
    public void delByIdsAndUrls(String ids, String urls) {
        String[] idArray = ids.split(",");
        String[] urlArray = urls.split(","); 
        if (!"".equals(idArray[0]) && !"".equals(urlArray[0])) {
            String[] sqls = new String[idArray.length];
            String[][] parameters = new String[idArray.length][1];            for (int i = 0; i < idArray.length; i++) {
                FileUtils.delete(urlArray[i]);
                sqls[i] = "delete from image where id = ?";
                parameters[i][0] = idArray[i];
            }
            DBUtils.updates(sqls, parameters);
        }
    }
}

创建用户控制器类：

/**
 * 用户控制器
 * @author www.shiyanlou.com
 *
 */
@WebServlet(value = "/UserAction")
public class UserAction extends HttpServlet { 
    private static final long serialVersionUID = 1L; 
 
    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("Utf-8");
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        UserService userService = new UserService();
        ImageService imageService = new ImageService();

        Integer type = Integer.valueOf(request.getParameter("type")); 
        if (type == 1) {    //用户登录
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            String result = null;
            User user = null; 
            //验证用户是否有效
            if (username.isEmpty()) {
                result = "1";
            } else if (password.isEmpty()) {
                result = "2";
            } else if ((user = userService.getUserByUsername(username)) == null) {
                result = "3";
            } else { 
                if (!user.getPassword().equals(password)) {
                    result = "4";
                } else {
                    request.getSession().setAttribute("user", user);
                    request.getSession().setAttribute("imageList", imageService.getByUserId(user.getId()));
                    result = "5";
                }
            }
            out.print(result);
        } else if (type == 2) {    //用户注册
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            String repassword = request.getParameter("repassword");
            String result = null; 
            //验证有效性
            if (username.isEmpty()) {
                result = "1";
            } else if (password.isEmpty()) {
                result = "2";
            } else if (repassword.isEmpty()) {
                result = "3";
            } else if (!repassword.equals(password)) {
                result = "4";
            } else if (userService.getUserByUsername(username) != null) {
                result = "5";
            } else {
                User user = new User(username, password); 
                //添加用户
                userService.addUser(user);
                result = "6";
            }
            out.print(result);
        } else if (type == 3) {    //用户退出
            request.getSession().invalidate();
        }
    } 

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
        this.doGet(request, response);
    }

}

创建图片控制器类：

/**
 * 图片控制器
 * @author www.shiyanlou.com
 *
 */
@WebServlet(value = "/ImageAction")
@MultipartConfig
public class ImageAction extends HttpServlet { 
    private static final long serialVersionUID = 1L; 
 
    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        Integer type = Integer.valueOf(request.getParameter("type"));
        ImageService imageService = new ImageService(); 
        if (type == 1) {    //上传图片
            String imageName = request.getParameter("image_name");
            Part image = request.getPart("image");
            Image img = new Image();
            img.setDate(new Date());
            img.setName(imageName);
            img.setUser((User) request.getSession().getAttribute("user"));
            img.setUrl(img.getUser().getUsername() + "/" + UUID.randomUUID());
            imageService.addImage(img, image.getInputStream());
            request.getSession().setAttribute("imageList", imageService.getByUserId(img.getUser().getId()));
            response.sendRedirect(request.getContextPath() + "/home.jsp");
        } else if (type == 2) {    //删除图片
            String ids = request.getParameter("ids");
            String urls = request.getParameter("urls");
            imageService.delByIdsAndUrls(ids, urls);
            request.getSession().setAttribute("imageList", imageService.getByUserId(((User) request.getSession().getAttribute("user")).getId()));
        }
    } 

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
        this.doGet(request, response);
    }

}