taskservice.jsp

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<%@ page contentType="text/plain; charset=UTF-8"%>
<%@ page language="java"%>
<%@ page import="java.sql.*,ajax.db.DBUtils,org.json.simple.JSONObject,org.json.simple.JSONArray"%>
<%!
    String sessionKey = "_LOGIN_USER_";             //session内登录key

    //用户登录
    String login(String userName, String password, HttpSession session) {
        StringBuffer result = new StringBuffer();
        String sql = "select id, name, password from task_users where name = ?";//定义SQL语句
        Connection conn = null;                     //声明Connection对象
        PreparedStatement pstmt = null;             //声明PreparedStatement对象
        ResultSet rs = null;                        //声明ResultSet对象
        try {
            conn = DBUtils.getConnection();         //获取数据库连接
            pstmt = conn.prepareStatement(sql);     //根据sql创建PreparedStatement
            pstmt.setString(1, userName);           //设置参数
            rs = pstmt.executeQuery();              //执行查询，返回结果集
            if (rs.next()) {
                String dbPass = rs.getString("password");       //获取密码
                //根据密码匹配结果设置不同输出结果
                if (dbPass.equals(password)) {                  //登录成功
                    session.setAttribute(sessionKey, rs.getString("id")); //设置session值
                    result.append("1");                         //结果第一个字符设置为1
                    result.append("<div>欢迎用户 " + userName + " 登录系统。</div>");
                    result.append("<input type='button' value='退出' onclick='logout()'>");
                } else {                                        //登录失败
                    result.append("0");                         //结果第一个字符设置为0
                    result.append("密码错误。");
                }
            } else {                                            //登录失败
                result.append("0");                             //结果第一个字符设置为0
                result.append("该用户不存在。");
            }
        } catch (SQLException e) {
            System.out.println(e.toString());
        } finally {
            DBUtils.close(rs);                  //关闭结果集
            DBUtils.close(pstmt);               //关闭PreparedStatement
            DBUtils.close(conn);                //关闭连接
        }
        return result.toString();
    }

    //获取任务列表
    String getLists(String userId) {
        JSONArray array = new JSONArray();      //定义JSON数组
        StringBuffer result = new StringBuffer("[");
        String sql = "select id, listname from task_lists where userid = ? order by listname asc";   //定义SQL语句
        Connection conn = null;                 //声明Connection对象
        PreparedStatement pstmt = null;         //声明PreparedStatement对象
        ResultSet rs = null;                    //声明ResultSet对象
        try {
            conn = DBUtils.getConnection();     //获取数据库连接
            pstmt = conn.prepareStatement(sql); //根据sql创建PreparedStatement
            pstmt.setString(1, userId);         //设置参数
            rs = pstmt.executeQuery();
            //遍历结果集，给JSON数组中加入JSONObject
            while (rs.next()) {
                JSONObject obj = new JSONObject();
                obj.put("id", rs.getString(1));
                obj.put("name", rs.getString(2));
                array.add(obj);
            }
        } catch (SQLException e) {
            System.out.println(e.toString());
        } finally {
            DBUtils.close(rs);                  //关闭结果集
            DBUtils.close(pstmt);               //关闭PreparedStatement
            DBUtils.close(conn);                //关闭连接
        }
        return array.toString();
    }

    //获取任务
    String getTasks(String userId, String listId) {
        JSONArray array = new JSONArray();      //定义JSON数组
        String sql = "select id, taskname, status from task_tasks where userid = ? and listid = ? order by taskname asc";   //定义SQL语句
        Connection conn = null;                 //声明Connection对象
        PreparedStatement pstmt = null;         //声明PreparedStatement对象
        ResultSet rs = null;                    //声明ResultSet对象
        try {
            conn = DBUtils.getConnection();     //获取数据库连接
            pstmt = conn.prepareStatement(sql); //根据sql创建PreparedStatement
            pstmt.setString(1, userId);         //设置参数
            pstmt.setString(2, listId);         //设置参数
            rs = pstmt.executeQuery();
            //遍历结果集，给JSON数组中加入JSONObject
            while (rs.next()) {
                JSONObject obj = new JSONObject();
                obj.put("id", rs.getString(1));
                obj.put("name", rs.getString(2));
                obj.put("status", rs.getString(3));
                array.add(obj);
            }
        } catch (SQLException e) {
            System.out.println(e.toString());
        } finally {
            DBUtils.close(rs);                  //关闭结果集
            DBUtils.close(pstmt);               //关闭PreparedStatement
            DBUtils.close(conn);                //关闭连接
        }
        return array.toString();
    }

    //改变任务状态
    void changeTaskStatus(String userId, String taskId, String status) {
        String sql = "update task_tasks set status = ? where userid = ? and id = ?";   //定义SQL语句
        Connection conn = null;                 //声明Connection对象
        PreparedStatement pstmt = null;         //声明PreparedStatement对象
        try {
            conn = DBUtils.getConnection();     //获取数据库连接
            pstmt = conn.prepareStatement(sql); //根据sql创建PreparedStatement
            pstmt.setString(1, status);         //设置参数
            pstmt.setString(2, userId);         //设置参数
            pstmt.setString(3, taskId);         //设置参数
            pstmt.executeUpdate();              //执行更新
        } catch (SQLException e) {
            System.out.println(e.toString());
        } finally {
            DBUtils.close(pstmt);               //关闭PreparedStatement
            DBUtils.close(conn);                //关闭连接
        }
    }

    //添加任务列表
    void addList(String userId, String listName) {
        String sql = "insert into task_lists(userid, listname) values(?,?)";   //定义SQL语句
        Connection conn = null;                 //声明Connection对象
        PreparedStatement pstmt = null;         //声明PreparedStatement对象
        try {
            conn = DBUtils.getConnection();     //获取数据库连接
            pstmt = conn.prepareStatement(sql); //根据sql创建PreparedStatement
            pstmt.setString(1, userId);         //设置参数
            pstmt.setString(2, listName);       //设置参数
            pstmt.executeUpdate();              //执行插入
        } catch (SQLException e) {
            System.out.println(e.toString());
        } finally {
            DBUtils.close(pstmt);               //关闭PreparedStatement
            DBUtils.close(conn);                //关闭连接
        }
    }

    //删除任务列表
    void delList(String userId, String listId) {
        String sql1 = "delete from task_tasks where userid = ? and listid = ?"; //删除任务SQL
        String sql2 = "delete from task_lists where userid = ? and id = ?";     //删除列表SQL
        Connection conn = null;                 //声明Connection对象
        PreparedStatement pstmt = null;         //声明PreparedStatement对象
        try {