这篇文章主要介绍了JavaWeb简单用户登录注册实例代码，文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值，需要的朋友们下面随着小编来一起学习学习吧

需求

编写login登录界面(用户名，密码，验证码，登陆按钮，注册按钮)

设计关系数据库(编号，用户名，密码)

编写注册功能，将数据存储在数据库中。（姓名不能重复，设为主键，重复会注册失败）

编写登录功能。首先获取验证码，先判断验证码是否正确，不正确则显示验证码错误。验证码正确后再获取用户名和密码，进行数据库的搜索比对，若正确则重定向到成功的界面，并且将用户名显示。

jar包

技术选型

Servlet + JSP + MysqL + JDBCTemplate + Druid + BeanUtils + Tomcat

效果图

验证码或者用户名和密码错误

Navicat Premium 显示 MysqL 内容

登录成功

注册功能

源码

登录主界面 login.jsp

用户名

密码

验证码

${requestScope.login_error}

${requestScope.checkcode_error}

注册界面 register.jsp

Title

用户名

密码

${requestScope.register_success}

${requestScope.register_error}

成功界面 success.jsp

Title${requestScope.user},欢迎您 --%>

,欢迎您

先编辑好JDBCUtils工具类

package cn.code.util; import com.alibaba.druid.pool.DruidDataSourceFactory; import javax.sql.DataSource; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.sqlException; import java.util.Properties; /** * JDBC工具类使用Durid连接池 */ public class JDBCUtils { private static DataSource ds; static{ try { //加载配置文件 Properties pro = new Properties(); //使用ClassLoader加载配置文件，获取字节输入流 InputStream is = JDBCUtils.class.getClassLoader().getResourceAsstream("druid.properties"); pro.load(is); //初始化连接池对象 ds = DruidDataSourceFactory.createDataSource(pro); } catch (Exception e) { e.printstacktrace(); } } /** * 获取连接池对象 */ public static DataSource getDataSource(){ return ds; } /** * 获取连接connection对象 */ public static Connection getConnection() throws sqlException { return ds.getConnection(); } }

创建我们的用户类实体User

package cn.code.domain; /* 用户的实体类 */ public class User { private int id ; private String username; private String password; 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; } @Override public String toString() { return "User{" + "id=" + id + ", username='" + username + ''' + ", password='" + password + ''' + '}'; } }

编写Dao来操作数据库，里面有login和add两个方法 Userdao

package cn.code.dao; import cn.code.domain.User; import cn.code.util.JDBCUtils; import org.springframework.dao.DataAccessException; import org.springframework.jdbc.core.BeanPropertyRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import java.sql.Connection; import java.sql.sqlException; import java.sql.Statement; /** * 操作数据库中User表的类 */ public class UserDao { //声明JDBCTemplate对象，以便方法公用 private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource()); /** * 登录方法 * * @param loginUser 目前只有用户名和密码 * @return user包含用户全部数据 */ public User login(User loginUser) { //编写sql String sql = "select * from user where username = ? and password = ?"; //调用query方法 try { User user = template.queryForObject(sql, new BeanPropertyRowMapper(User.class), loginUser.getUsername(), loginUser.getpassword()); return user; } catch (DataAccessException e) { e.printstacktrace(); return null; } } /** * 注册方法 * * @param user 目前只包含用户名和密码 * @return 是否注册成功 */ public boolean add(User user){ //编写sql String sql = "insert into user (username,password) VALUES('" + user.getUsername() + "','" + user.getpassword() + "')"; boolean flag = false; int num = 0; try { //创建数据库连接 Connection conn = JDBCUtils.getConnection(); Statement state = null; flag = false; num = 0; state = conn.createStatement(); num = state.executeUpdate(sql); } catch (sqlException e) { e.printstacktrace(); } if(num >0) flag = true; return flag; } }

登录的Servlet

package cn.code.servlet; import cn.code.dao.UserDao; import cn.code.domain.User; 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 javax.servlet.http.HttpSession; import java.io.IOException; @WebServlet("/loginServlet") public class LoginServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws servletexception, IOException { //设置字符编码 request.setCharacterEncoding("utf-8"); //获取参数 String username = request.getParameter("username"); String password = request.getParameter("password"); String checkcode = request.getParameter("checkcode"); //获取生成的验证码 HttpSession session = request.getSession(); String checkcode_session =(String) session.getAttribute("checkcode_session"); //防止验证码存储删除Session中存储的验证码 session.removeAttribute("checkcode_session"); //判断验证码是否正确 if(checkcode_session != null && checkcode_session.equalsIgnoreCase(checkcode)){ //equalsIgnoreCase忽略大小写的比较 //验证码正确 User loginUser = new User(); loginUser.setUsername(username); loginUser.setPassword(password); User user = new UserDao().login(loginUser); if(user != null){ //用户名以及密码正确 //登录成功 //存储用户信息 session.setAttribute("user",username); //因为是两次请求，所以用Session //重定向到success.jsp response.sendRedirect(request.getcontextpath()+"/success.jsp"); }else{ //用户名及密码错误 //登录失败 //存储提示信息到request request.setAttribute("login_error","用户名或密码错误"); //转发到登录页面 request.getRequestdispatcher("/login.jsp").forward(request,response); } }else{ //验证码不正确 //存储提示信息到request request.setAttribute("checkcode_error","验证码错误"); //转发到登录页面 request.getRequestdispatcher("/login.jsp").forward(request,response); } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws servletexception, IOException { this.doPost(request, response); } }

注册的Servlet

在页面中画验证码（可点击更换）Servlet

package cn.code.checkcode; import javax.imageio.ImageIO; 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 java.awt.*; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; //简易验证码 @WebServlet("/checkCodeServlet") public class CheckCodeServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws servletexception, IOException { int width = 100; int height = 50; //创建一对象，在内存中代表图片（验证码图片对象） BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR); //美化图片 //填充背景色 Graphics g = image.getGraphics();//画笔对象 g.setColor(Color.ORANGE); g.fillRect(0,0,width,height); //画边框 g.setColor(Color.BLUE); g.drawRect(0,0,width-1,height-1); String str = "QWERTYUIOPASDFGHJKLZXCVBNM1234567890zxcvbnmlkjhgfdsaqwertyuiop"; //生成随机角标 StringBuilder sb = new StringBuilder(); Random ran = new Random(); for (int i = 1; i

JavaWeb简单用户登录注册实例代码(有验证码),欢迎您

,欢迎您

相关文章