Web實現數據庫鏈接的登錄注冊修改密碼功能

/**
 * Copyright (C), 2017-2017
 * FileName: User
 * Author:   ichimoku
 * Date:     2017/12/5 14:31
 * version:  7.9.0
 * <Author>          <Date>          <version>
 * 作者姓名          修改時間         版本號
 */
public class User {

    //登陸查詢  -----  括號內接收從網頁傳來的用戶輸入的參數
    public static Boolean CheckUser(String username,String password) {
        int count = 0;
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        // 1.加載驅動
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            System.out.println("加載驅動失敗");
        }
        // 2.建立連接
        try {
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/數據庫名", "用戶名", "密碼");
            /*System.out.println("建立連接成功！");*/

            String sql = "SELECT id FROM account WHERE name=? AND password=?";
            ps=conn.prepareStatement(sql);
            ps.setString(1,username);
            ps.setString(2,password);
            rs=ps.executeQuery();

            while (rs.next()){
                count++;
            }
            
        } catch (SQLException e) {
            System.out.println("建立連接失敗");
        } finally {
            // 3.關閉連接
            try {
                if (null != conn) {
                    conn.close();
                }
                if (null != ps) {
                    ps.close();
                }
                /*System.out.println("關閉連接成功!");*/
            } catch (SQLException e) {
                System.out.println("程序錯誤");
            }
        }
        return count>0 ? true:false;
    }


    //新增用戶   -----  括號內接收從網頁傳來的用戶輸入的參數
    public static void  AddUser(String username,String password) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        // 1.加載驅動
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            System.out.println("加載驅動失敗");
        }
        // 2.建立連接
        try {
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/數據庫名", "用戶名", "密碼");
            /*System.out.println("建立連接成功！");*/

            String sql = "INSERT INTO account SET (name,password) VALUE (?,?)";
            ps=conn.prepareStatement(sql);
            ps.setString(1,username);
            ps.setString(2,password);
            rs=ps.executeQuery();
        } catch (SQLException e) {
            System.out.println("建立連接失敗");
        } finally {
            // 3.關閉連接
            try {
                if (null != conn) {
                    conn.close();
                }
                if (null != ps) {
                    ps.close();
                }
                System.out.println("關閉連接成功!！！");
            } catch (SQLException e) {
                System.out.println("程序錯誤");
            }
        }
    }


    //修改密碼  ---  括號內接收從網頁傳來的用戶輸入的參數
    public static void  UpdateUser(String newpassword,String username,String password) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        // 1.加載驅動
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            System.out.println("加載驅動失敗");
        }
        // 2.建立連接
        try {
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/數據庫名", "用戶名", "密碼");
            /*System.out.println("建立連接成功！");*/

            String sql = "UPDATE account SET password=? WHERE name=? AND password=?";
            ps=conn.prepareStatement(sql);
            ps.setString(1,newpassword);
            ps.setString(2,username);
            ps.setString(3,password);
            rs=ps.executeQuery();

        } catch (SQLException e) {
            System.out.println("建立連接失敗");
        } finally {
            // 3.關閉連接
            try {
                if (null != conn) {
                    conn.close();
                }
                if (null != ps) {
                    ps.close();
                }
                System.out.println("關閉連接成功!");
            } catch (SQLException e) {
                System.out.println("程序錯誤");
            }
        }
    }
}

 

/**
 * Copyright (C), 2017-2017
 * FileName: Check
 * Author:   ichimoku
 * Date:     2017/12/5 14:40
 * version:  7.9.0
 * <Author>          <Date>          <version>
 * 作者姓名          修改時間         版本號
 */

@WebServlet(name="CheckUser",urlPatterns="/servlet/CheckUser")
public class CheckUser extends HttpServlet{
    private static final long serialVersionUID = 1L;

    public CheckUser(){
        super();
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //從網頁獲取輸入的用戶名和密碼
        String username = new String(req.getParameter("username").getBytes("iso-8859-1"), "utf-8");
        String password = req.getParameter("password");

        //在控制台打印從網頁獲取到的用戶名
        System.out.println(username);

        //判斷用戶名和密碼是否為空
        if (username!=null && password!=null){
            boolean flag= User.CheckUser(username,password);
            //通過flag返回值 為true就會執行if，false就會執行else
            if (flag){
                req.getRequestDispatcher("/pages/user/login_success.html").forward(req, resp);
            }else{
                //req.getRequestDispatcher("/pages/user//Welcome.jsp").forward(req, resp);
            }
        }else{
            System.out.println("用戶的輸入為空");
        }
    }
}

 

/**
 * Copyright (C), 2017-2017
 * FileName: Add
 * Author:   ichimoku
 * Date:     2017/12/5 16:01
 * version:  7.9.0
 * <Author>          <Date>          <version>
 * 作者姓名          修改時間         版本號
 */
@WebServlet(name="AddUser",urlPatterns="/servlet/AddUser")
public class AddUser extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public AddUser(){
        super();
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //從網頁獲取輸入的用戶名和密碼
        String username = new String(req.getParameter("username").getBytes("iso-8859-1"), "utf-8");
        String password = req.getParameter("password");

        //在控制台打印從網頁獲取到的用戶名
        System.out.println(username);

        //判斷用戶名和密碼是否為空
        if (username!=null && password!=null){
            boolean flag=User.CheckUser(username,password);
            //通過flag返回值 為true就會執行if，false就會執行else，因為我們要新增用戶，如果返回ture就說明
            //這個賬號已經有人使用，所以我們要提示注冊失敗，如果返回false,說明數據庫里沒有這個賬號，可以注冊
            //在else里運行AddUser的方法，成功數據庫在數據庫里新增注冊數據！
            if (flag){
                //req.getRequestDispatcher("/pages/user//Welcome.jsp").forward(req, resp);
            }else{
                //req.getRequestDispatcher("/pages/user//Welcome.jsp").forward(req, resp);
                User.AddUser(username,password);
                req.getRequestDispatcher("/pages/user/login_success.html").forward(req, resp);
            }
        }else{
            System.out.println("用戶的輸入為空");
        }
    }
}

 

/**
 * Copyright (C), 2017-2017
 * FileName: Update
 * Author:   ichimoku
 * Date:     2017/12/5 16:05
 * version:  7.9.0
 * <Author>          <Date>          <version>
 * 作者姓名          修改時間         版本號
 */

@WebServlet(name="UpdateUser",urlPatterns="/servlet/UpdateUser")
public class UpdateUser extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public UpdateUser(){
        super();
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //從網頁獲取輸入的用戶名和密碼
        String username = new String(req.getParameter("username").getBytes("iso-8859-1"), "utf-8");
        String password = req.getParameter("password");
        String newpassword = req.getParameter("newpassword");

        //在控制台打印從網頁獲取到的用戶名
        System.out.println(username);

        //判斷用戶名和密碼是否為空
        if (username!=null && password!=null){
            boolean flag=User.CheckUser(username,password);
            //通過flag返回值 為true就會執行if，false就會執行else，因為我們要修改密碼，所以當返回true，說明用戶輸入的賬號密碼
            // 和數據庫匹配成功！所以我們在if下面執行UpdateUser方法，修改數據庫數值！
            if (flag){
                User.UpdateUser(newpassword,username,password);
                req.getRequestDispatcher("/pages/user/login_success.html").forward(req, resp);
            }else{
                //req.getRequestDispatcher("/pages/user//Welcome.jsp").forward(req, resp);
            }
        }else {
            System.out.println("用戶的輸入為空");
        }
    }
}