JavaWeb简单用户登录注册实例代码(有验证码)

JavaWeb简单用户登录注册实例代码(有验证码)

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

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

注册界面 register.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

成功界面 success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%--

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.DataAchttp://cessException;

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

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 java.io.IOException;

@WebServlet("/registerServlet")

public class RegisterServlet extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding("utf-8");

String username = request.getParameter("username");

String password = request.getParameter("password");

User registerUser = new User();

registerUser.setUsername(username);

registerUser.setPassword(password);

boolean flag = new UserDao().add(registerUser);

if(flag) {

request.setAttribute("register_success","注册成功");

request.getRequestDispatcher("/register.jsp").forward(request,response);

}else{

request.setAttribute("register_error","账号以被注册,注册失败");

request.getRequestDispatcher("/register.jsp").forward(request,response);

}

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

this.doPost(request,response);

}

}

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 <= 4; i++) {

int index = ran.nextInt(str.length());

//获取字符

char ch = str.charAt(index);

sb.append(ch);

//写验证码

g.drawString(ch+"",width/5*i,height/2);

}

String checkcode_session = sb.toString();

//将验证码存入session

request.getSession().setAttribute("checkcode_session",checkcode_session);

//画干扰线

g.setColor(Color.RED);

//随机生成坐标点

for (int i = 0 ;i<6;i++) {

int x1 = ran.nextInt(width);

int x2 = ran.nextInt(width);

int y1 = ran.nextInt(height);

int y2 = ran.nextInt(height);

g.drawLine(x1,y1,x2,y2);

}

//将图片输出到页面展示

ImageIO.write(image, "jpg", response.getOutputStream());

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

this.doPost(request, response);

}

}

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