java web之登录注册

作者: 猫不爱吃鱼 | 来源:发表于2017-08-11 20:24 被阅读254次

    本文实现一个简单的java web项目功能---登录注册,目的是对前一段做的学习做个总结,以后有需要的话也可以直接拿来改改就能用,仅此。


    版权声明:欢迎转载,转载请注明出处,谢谢!(如有侵权之处,也请联系修改或删除!)


    1.实现效果如下:

    1.1登录:

    登录.png

    1.2注册:

    注册.png

    2.Eclipse 项目结构:

    项目结构.png

    3.具体实现:

    3.1 数据库建表(user_info):

    表名为:user_info

    3.2 链接到数据库(JDBCUtil.java)

    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    
    public class JDBCUtil {
        static String username = "yourusername";
        static String password = "yourpassword";
        static String driver = "com.mysql.jdbc.Driver";
        static String url = "jdbc:mysql://localhost:3306/yoursqluame?useSSL=false";
        //获取链接
        public static Connection getConn(){
            Connection conn = null;
            try {
                Class.forName(driver);
                conn = DriverManager.getConnection(url,username, password);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return conn;
        }
        //释放链接
        public static void release(Statement stmt,Connection conn){
            if(stmt != null){
                try {
                    stmt.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(conn != null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
        //重载释放链接
        public static void release(ResultSet rs ,Statement stmt,Connection conn){
            if(rs != null){
                try {
                    rs.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(stmt != null){
                try {
                    stmt.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(conn != null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
    

    3.3 用户类(UserBean.java)

    • login.jsp
    package com.Bean;
    
    public class UserBean {
        private String userName;
        private String password;
        private String userEmail;
        
        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;
        }
        public String getUserEmail() {
            return userEmail;
        }
        public void setUserEmail(String userEmail) {
            this.userEmail = userEmail;
        }
        
        public UserBean(){
        }
        
        public UserBean(String userName,String password,String userEmail){
            this.userName = userName;
            this.password = password;
            this.userEmail = userEmail;
        }
        
    }
    

    3.4 Login与Register的jsp编写(login.jsp&&register.jsp)

    • login.jsp
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%
        String path = request.getContextPath();
    %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>登录</title>
    
    <script type="text/javascript">
    function login(){
        var th = document.form1;
        if(th.email.value==""){
            alert("Email Can't Be Bull");
            th.email.focus();
            return;
        }
        if(th.password.value==""){
            alert("Password Can't Be Null");
            th.password.focus();
            return;
        }
        th.action="<%=path%>/LoginServlet";
            th.submit();
        }
    </script>
    <script type="text/javascript">
        function change() {
            var img = document.getElementById("verify");
            img.src = "VerifyCodeServlet?a=" + new Date().getTime();
        }
    </script>
    
    </head>
    <body>
        <div align="center">
            <form name="form1" action="" method="post">
                <table>
                    <tr>
                        <td>邮箱:</td>
                        <td><input name="email"></td>
                    </tr>
                    <tr>
                        <td>密码:</td>
                        <td><input name="password" type="password"></td>
                    </tr>
                    <tr>
                        <td>验证码:</td>
                        <td><input type="text" name="verifycode"></td>
                        <td><a href="javascript:change()">![](VerifyCodeServlet)</a></td>
                    </tr>
                    <tr>
                        <td><input type="button" value="登录" onclick="login()"></td>
                        <td><input type="button" value="注册" onclick="javascript:location.href='register.jsp'">
                    </tr>
                    <tr>${msg}</tr>
    
                </table>
            </form>
        </div>
    </body>
    </html>
    
    • register.jsp
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    %>
    <!DOCTYPE html>
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Register</title>
    <script type="text/javascript">
    function register(){
        var th = document.form1;
        if(th.userName.value==""){
            alert("UserName Can't Be Null");
            th.userName.focus();
            return;
        }
        if(th.email.value==""){
            alert("Email Can't Be Null");
            th.email.focus();
            return;
        }
        if(th.password.value==""){
            alert("Password Can't Be Null");
            th.password.focus();
            return;
        }
        if(th.password.value != th.psw.value){
            alert("The Two Passwords Don't Match!");
            th.psw.focus();
            return;
        }
        th.action="<%=path%>/RegisterServlet";
        th.submit();
    }
    </script>
    </head>
    <body>
        <div align="center">
            <form name="form1" action="" method="post">
                <table>
                    <tr>
                        <td>UserName:</td>
                        <td><input name="userName"></td>
                    </tr>
                    <tr>
                        <td>Email:</td>
                        <td><input name="email"></td>
                    </tr>
                    <tr>
                        <td>Password:</td>
                        <td><input type="password" name="password"></td>
                    </tr>
                    <tr>
                        <td>ConfirmPassword:</td>
                        <td><input type="password" name="psw"></td>
                    </tr>
                    <tr>
                        <td><input type="button" value="注册" onclick="register()"></td>
                        <td><input type="button" value="返回"
                            onclick="javascript:location.href='login.jsp'">
                    </tr>
                    <tr>${msg}</tr>
                </table>
            </form>
        </div>
    </body>
    </html>
    
    • welcome.jsp
    <%@ 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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Welcome</title>
    </head>
    <body>
    Welcome ${userName}
    </body>
    </html>
    

    3.5 Servlet以及Dao层的实现

    -LoginServlet.java

    package com.Servlet;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import com.Dao.UserDao;
    
    
    /**
     * Servlet implementation class LoginServlet
     */
    @WebServlet("/LoginServlet")
    public class LoginServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public LoginServlet() {
            super();
            // TODO Auto-generated constructor stub
        }
    
        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            request.setCharacterEncoding("utf-8");
            response.setContentType("text/html;charset=utf-8");
            
            String email = request.getParameter("email");
            String password = request.getParameter("password");
            String verifyc  = request.getParameter("verifycode");
            String svc =(String) request.getSession().getAttribute("sessionverify");
            
            if(!svc.equalsIgnoreCase(verifyc)){
                request.setAttribute("msg", "验证码错误!");
                request.getRequestDispatcher("/login.jsp").forward(request, response);
                return;
            }
            
            String userName = new UserDao().login(email,password);
            
            if(userName == null){
                request.setAttribute("msg", "用户名或密码错误!");
                request.getRequestDispatcher("/login.jsp").forward(request, response);
                return;
            }else{
                request.setAttribute("userName", userName);
                request.getRequestDispatcher("/welcome.jsp").forward(request, response);
                return;
            }
            
        }
    
        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            doGet(request, response);
        }
    
    }
    

    -RegisterServlet.java

    package com.Servlet;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import com.Bean.UserBean;
    import com.Dao.UserDao;
    
    /**
     * Servlet implementation class RegisterServlet
     */
    @WebServlet("/RegisterServlet")
    public class RegisterServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public RegisterServlet() {
            super();
            // TODO Auto-generated constructor stub
        }
    
        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            request.setCharacterEncoding("utf-8");
            response.setContentType("text/html;charset=utf-8");
            
            String userName = request.getParameter("userName");
            String email = request.getParameter("email");
            String password = request.getParameter("password");
            
            boolean flag = new UserDao().checkEmail(email);
            
            if(flag){
                request.setAttribute("msg", "此邮箱已被注册!");
                request.getRequestDispatcher("register.jsp").forward(request, response);
                return;
            }else{
                new UserDao().register(userName,email,password);
                request.setAttribute("msg", "欢迎您"+userName+",注册成功!");
                request.getRequestDispatcher("login.jsp").forward(request, response);
                return;
            }
        }
    
        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            doGet(request, response);
        }
    
    }
    
    • UserDao.java
    package com.Dao;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import com.Bean.UserBean;
    import com.JDBCUtil.JDBCUtil;
    
    public class UserDao {
    //登录检测
        public String login(String email, String password) {
            // TODO Auto-generated method stub
            String username = null;
            Connection conn = null;
            PreparedStatement pstmt = null;
            ResultSet rs = null;
            
            try {
                conn =JDBCUtil.getConn();
                String sql = "select user_name from user_info where user_email=? and user_password=?;";
                pstmt = conn.prepareStatement(sql);
                pstmt.setString(1, email);
                pstmt.setString(2, password);
                rs = pstmt.executeQuery();
                
                while(rs.next()){
                    username = rs.getString("user_name");
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                JDBCUtil.release(rs, pstmt, conn);
            }
            
            return username;
        }
    //检测邮箱是否已使用
        public boolean checkEmail(String email) {
            // TODO Auto-generated method stub
            boolean flag = false;
            Connection conn = null;
            PreparedStatement pstmt = null;
            ResultSet rs = null;
            
            try {
                conn = JDBCUtil.getConn();
                String sql = "select * from user_info where user_email =?";
                pstmt = conn.prepareStatement(sql);
                pstmt.setString(1, email);
                rs = pstmt.executeQuery();
                
                while(rs.next()){
                    flag = true; 
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                JDBCUtil.release(rs, pstmt, conn);
            }
            
            return flag;
        }
    //注册用户
        public void register(String userName,String email,String password) {
            // TODO Auto-generated method stub
            Connection conn = null;
            PreparedStatement pstmt = null;
            
            
            try {
                conn = JDBCUtil.getConn();
                String sql = "insert into user_info values("+userName+","+email+","+password+");";
                pstmt = conn.prepareStatement(sql);
                pstmt.executeUpdate(sql);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                JDBCUtil.release(pstmt, conn);
            }
            
            
        }
    
    }
    
    • VerifyCodeServlet.java
    package com.Servlet;
    
    import java.awt.image.BufferedImage;
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import com.Dao.VerifyCode;
    
    /**
     * Servlet implementation class VerifyCodeServlet
     */
    @WebServlet("/VerifyCodeServlet")
    public class VerifyCodeServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public VerifyCodeServlet() {
            super();
            // TODO Auto-generated constructor stub
        }
    
        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            VerifyCode vc = new VerifyCode();  
            BufferedImage image = vc.getImage(85,23); 
            request.getSession().setAttribute("sessionverify", vc.getText());
            VerifyCode.output(image, response.getOutputStream()); 
        }
    
        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            doGet(request, response);
        }
    
    }
    
    • VerifyCode.java
    package com.Dao;
    
    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.util.Random;
    
    import javax.imageio.ImageIO;
    
    public class VerifyCode {
    
        public static final char[] CHARS = { '2', '3', '4', '5', '6', '7', '8',  
                '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',  
                'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };  
      
        public static Random random = new Random();  
      
        public String getRandomString() {  
            StringBuffer buffer = new StringBuffer();  
            for (int i = 0; i < 4; i++) {  
                buffer.append(CHARS[random.nextInt(CHARS.length)]);  
            }  
            return buffer.toString();  
        }  
      
        public  Color getRandomColor() {  
            return new Color(random.nextInt(255), random.nextInt(255), random  
                    .nextInt(255));  
        }  
      
        public  Color getReverseColor(Color c) {  
            return new Color(255 - c.getRed(), 255 - c.getGreen(), 255 - c  
                    .getBlue());  
        }  
        String text = getRandomString();  
        public String getText() {  
            return text;  
        }  
      
        public BufferedImage getImage(int width,int height ){  
            Color color = getRandomColor();  
            Color reverse = getReverseColor(color);  
      
            BufferedImage bi = new BufferedImage(width, height,  
                    BufferedImage.TYPE_INT_RGB);  
            Graphics2D g = bi.createGraphics();  
            g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));  
            g.setColor(color);  
            g.fillRect(0, 0, width, height);  
            g.setColor(reverse);  
            g.drawString(text, 10, 22);  
            for (int i = 0, n = random.nextInt(80); i < n; i++) {  
                g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);  
            }  
            return bi;  
              
        }  
        public static void output(BufferedImage image, OutputStream out) throws IOException{  
            ImageIO.write(image, "JPEG", out);  
        }
    }
    

    3.6 web.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
      <display-name>Blog_Demo</display-name>
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
    </web-app>
    

    *说明:

    1.数据库链接需要导入对应的jar包--mysql-connector-java-5.1.43-bin.jar。
    2.直接粘贴复制,若出现中文变为乱码的情况,请转换项目字符格式或手动更改即可。


    (* 第一次写文章,排版有可能不是很好理解,有什么建议欢迎指出!谢谢!)

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      网友评论

      • 夜晚雨:有想学习java编程的,可以咨询我微信2683002850
      • 夜晚雨:有想学习java编程的,可以咨询我微信2683002850
      • 摆渡人_0c3b:很好,请问,都需要哪些jar包?
        猫不爱吃鱼:mysql-connector-java-5.1.43-bin.jar这个是链接数据库用的。这个功能比较简单,只用到了这一个。(不好意思,之前没有看到,希望对你有所帮助)
      • usiantein:谢谢了最近正好需要用到这些
        猫不爱吃鱼: @檀箫风笙 有用就好,不足之处还请多多指教
      • 纪信:很棒呀
        猫不爱吃鱼: @纪信 哇,感谢!

      本文标题:java web之登录注册

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