会话跟踪技术- 案例 - 登录注册
案例（登录注册）
用户登录
userMapper.java
public interface UserMapper {
/**
* 根据用户名和密码查询用户对象
* @param username
* @param password
* @return
*/
@Select("select * from tb_user where username = #{username} and password = #{password}")
User select(@Param("username") String username,@Param("password") String password);
/**
* 根据用户名查询用户对象
* @param username
* @return
*/
@Select("select * from tb_user where username = #{username}")
User selectByUsername(String username);
/**
* 添加用户
* @param user
*/
@Insert("insert into tb_user values(null,#{username},#{password})")
void add(User user);
}
User.java
public class User {
private Integer id;
private String username;
private String password;
public Integer getId() {
return id;
}
public void setId(Integer 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 + '\'' +
'}';
}
}
userMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.UserMapper">
</mapper>
UserService
public class UserService {
SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
/**
* 登录方法
* @param username
* @param password
* @return
*/
public User login(String username,String password){
//2. 获取SqlSession
SqlSession sqlSession = factory.openSession();
//3. 获取UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//4. 调用方法
User user = mapper.select(username, password);
//释放资源
sqlSession.close();
return user;
}
/**
* 注册方法
* @return
*/
public boolean register(User user){
//2. 获取SqlSession
SqlSession sqlSession = factory.openSession();
//3. 获取UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//4. 判断用户名是否存在
User u = mapper.selectByUsername(user.getUsername());
if(u == null){
// 用户名不存在，注册
mapper.add(user);
sqlSession.commit();
}
sqlSession.close();
return u == null;
}
}
login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>login</title>
<link href="css/login.css" rel="stylesheet">
</head>
<body>
<div id="loginDiv" style="height: 350px">
<form action="/brand-demo/loginServlet" method="post" id="form">
<h1 id="loginMsg">LOGIN IN</h1>
<div id="errorMsg">${login_msg} ${register_msg}</div>
<p>Username:<input id="username" name="username" value="${cookie.username.value}" type="text"></p>
<p>Password:<input id="password" name="password" value="${cookie.password.value}" type="password"></p>
<p>Remember:<input id="remember" name="remember" value="1" type="checkbox"></p>
<div id="subDiv">
<input type="submit" class="button" value="login up">
<input type="reset" class="button" value="reset">
<a href="register.jsp">没有账号？</a>
</div>
</form>
</div>
</body>
</html>
loginServlet
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
//获取复选框数据
String remember = request.getParameter("remember");
//2. 调用service查询
User user = service.login(username, password);
//3. 判断
if(user != null){
//登录成功，跳转到查询所有的BrandServlet
//判断用户是否勾选记住我
if("1".equals(remember)){
//勾选了，发送Cookie
//1. 创建Cookie对象
Cookie c_username = new Cookie("username",username);
Cookie c_password = new Cookie("password",password);
// 设置Cookie的存活时间
c_username.setMaxAge( 60 * 60 * 24 * 7);
c_password.setMaxAge( 60 * 60 * 24 * 7);
//2. 发送
response.addCookie(c_username);
response.addCookie(c_password);
}
//将登陆成功后的user对象，存储到session
HttpSession session = request.getSession();
session.setAttribute("user",user);
String contextPath = request.getContextPath();
response.sendRedirect(contextPath+"/selectAllServlet");
}else {
// 登录失败,
// 存储错误信息到request
request.setAttribute("login_msg","用户名或密码错误");
// 跳转到login.jsp
request.getRequestDispatcher("/login.jsp").forward(request,response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
selectAllServlet
@WebServlet("/selectAllServlet")
public class SelectAllServlet extends HttpServlet {
private BrandService service = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. 调用BrandService完成查询
List<Brand> brands = service.selectAll();
//2. 存入request域中
request.setAttribute("brands",brands);
//3. 转发到brand.jsp
request.getRequestDispatcher("/brand.jsp").forward(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
brand.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>${user.username},欢迎您</h1>
<input type="button" value="新增" id="add"><br>
<hr>
<table border="1" cellspacing="0" width="80%">
<tr>
<th>序号</th>
<th>品牌名称</th>
<th>企业名称</th>
<th>排序</th>
<th>品牌介绍</th>
<th>状态</th>
<th>操作</th>
</tr>
<c:forEach items="${brands}" var="brand" varStatus="status">
<tr align="center">
<%--<td>${brand.id}</td>--%>
<td>${status.count}</td>
<td>${brand.brandName}</td>
<td>${brand.companyName}</td>
<td>${brand.ordered}</td>
<td>${brand.description}</td>
<c:if test="${brand.status == 1}">
<td>启用</td>
</c:if>
<c:if test="${brand.status != 1}">
<td>禁用</td>
</c:if>
<td><a href="/brand-demo/selectByIdServlet?id=${brand.id}">修改</a> <a href="#">删除</a></td>
</tr>
</c:forEach>
</table>
<script>
document.getElementById("add").onclick = function (){
location.href = "/brand-demo/addBrand.jsp";
}
</script>
</body>
</html>
记住用户--写Cookie
实例（loginServlet）
//获取复选框数据
String remember = request.getParameter("remember");
//2. 调用service查询
User user = service.login(username, password);
//3. 判断
if(user != null){
//登录成功，跳转到查询所有的BrandServlet
//判断用户是否勾选记住我
if("1".equals(remember)){
//勾选了，发送Cookie
//1. 创建Cookie对象
Cookie c_username = new Cookie("username",username);
Cookie c_password = new Cookie("password",password);
// 设置Cookie的存活时间
c_username.setMaxAge( 60 * 60 * 24 * 7);
c_password.setMaxAge( 60 * 60 * 24 * 7);
//2. 发送
response.addCookie(c_username);
response.addCookie(c_password);
}
记住用户--获取Cookie
实例（value部分）
<p>Username:<input id="username" name="username" value="${cookie.username.value}" type="text"></p>
<p>Password:<input id="password" name="password" value="${cookie.password.value}" type="password"></p>
注册案例
UserService（注册方法）
public class UserService {
SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
/**
* 登录方法
* @param username
* @param password
* @return
*/
public User login(String username,String password){
//2. 获取SqlSession
SqlSession sqlSession = factory.openSession();
//3. 获取UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//4. 调用方法
User user = mapper.select(username, password);
//释放资源
sqlSession.close();
return user;
}
/**
* 注册方法
* @return
*/
public boolean register(User user){
//2. 获取SqlSession
SqlSession sqlSession = factory.openSession();
//3. 获取UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//4. 判断用户名是否存在
User u = mapper.selectByUsername(user.getUsername());
if(u == null){
// 用户名不存在，注册
mapper.add(user);
sqlSession.commit();
}
sqlSession.close();
return u == null;
}
}
register.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>欢迎注册</title>
<link href="css/register.css" rel="stylesheet">
</head>
<body>
<div class="form-div">
<div class="reg-content">
<h1>欢迎注册</h1>
<span>已有帐号？</span> <a href="login.html">登录</a>
</div>
<form id="reg-form" action="/brand-demo/registerServlet" method="post">
<table>
<tr>
<td>用户名</td>
<td class="inputs">
<input name="username" type="text" id="username">
<br>
<span id="username_err" class="err_msg" >${register_msg}</span>
</td>
</tr>
<tr>
<td>密码</td>
<td class="inputs">
<input name="password" type="password" id="password">
<br>
<span id="password_err" class="err_msg" style="display: none">密码格式有误</span>
</td>
</tr>
<tr>
<td>验证码</td>
<td class="inputs">
<input name="checkCode" type="text" id="checkCode">
<img id="checkCodeImg" src="/brand-demo/checkCodeServlet">
<a href="#" id="changeImg" >看不清？</a>
</td>
</tr>
</table>
<div class="buttons">
<input value="注 册" type="submit" id="reg_btn">
</div>
<br class="clear">
</form>
</div>
<script>
document.getElementById("changeImg").onclick = function () {
document.getElementById("checkCodeImg").src = "/brand-demo/checkCodeServlet?"+new Date().getMilliseconds();
}
</script>
</body>
</html>
registerServlet
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. 获取用户名和密码数据
String username = request.getParameter("username");
String password = request.getParameter("password");
User user = new User();
user.setUsername(username);
user.setPassword(password);
// 获取用户输入的验证码
String checkCode = request.getParameter("checkCode");
// 程序生成的验证码，从Session获取
HttpSession session = request.getSession();
String checkCodeGen = (String) session.getAttribute("checkCodeGen");
// 比对
if(!checkCodeGen.equalsIgnoreCase(checkCode)){
request.setAttribute("register_msg","验证码错误");
request.getRequestDispatcher("/register.jsp").forward(request,response);
// 不允许注册
return;
}
//2. 调用service 注册
boolean flag = service.register(user);
//3. 判断注册成功与否
if(flag){
//注册功能，跳转登陆页面
request.setAttribute("register_msg","注册成功，请登录");
request.getRequestDispatcher("/login.jsp").forward(request,response);
}else {
//注册失败，跳转到注册页面
request.setAttribute("register_msg","用户名已存在");
request.getRequestDispatcher("/register.jsp").forward(request,response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
验证码功能 —— 展示验证码
CheckCodeUtil（生成验证码工具类）
/**
* 生成验证码工具类
*/
public class CheckCodeUtil {
public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
private static Random random = new Random();
public static void main(String[] args) throws IOException {
OutputStream fos = new FileOutputStream("d://a.jpg");
String checkCode = CheckCodeUtil.outputVerifyImage(100, 50, fos, 4);
System.out.println(checkCode);
}
/**
* 输出随机验证码图片流,并返回验证码值（一般传入输出流，响应response页面端，Web项目用的较多）
*
* @param width 图片宽度
* @param height 图片高度
* @param os 输出流
* @param verifySize 数据长度
* @return 验证码数据
* @throws IOException
*/
public static String outputVerifyImage(int width, int height, OutputStream os, int verifySize) throws IOException {
String verifyCode = generateVerifyCode(verifySize);
outputImage(width, height, os, verifyCode);
return verifyCode;
}
/**
* 使用系统默认字符源生成验证码
*
* @param verifySize 验证码长度
* @return
*/
public static String generateVerifyCode(int verifySize) {
return generateVerifyCode(verifySize, VERIFY_CODES);
}
/**
* 使用指定源生成验证码
*
* @param verifySize 验证码长度
* @param sources 验证码字符源
* @return
*/
public static String generateVerifyCode(int verifySize, String sources) {
// 未设定展示源的字码，赋默认值大写字母+数字
if (sources == null || sources.length() == 0) {
sources = VERIFY_CODES;
}
int codesLen = sources.length();
Random rand = new Random(System.currentTimeMillis());
StringBuilder verifyCode = new StringBuilder(verifySize);
for (int i = 0; i < verifySize; i++) {
verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
}
return verifyCode.toString();
}
/**
* 生成随机验证码文件,并返回验证码值 (生成图片形式，用的较少)
*
* @param w
* @param h
* @param outputFile
* @param verifySize
* @return
* @throws IOException
*/
public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
String verifyCode = generateVerifyCode(verifySize);
outputImage(w, h, outputFile, verifyCode);
return verifyCode;
}
/**
* 生成指定验证码图像文件
*
* @param w
* @param h
* @param outputFile
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
if (outputFile == null) {
return;
}
File dir = outputFile.getParentFile();
//文件不存在
if (!dir.exists()) {
//创建
dir.mkdirs();
}
try {
outputFile.createNewFile();
FileOutputStream fos = new FileOutputStream(outputFile);
outputImage(w, h, fos, code);
fos.close();
} catch (IOException e) {
throw e;
}
}
/**
* 输出指定验证码图片流
*
* @param w
* @param h
* @param os
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
int verifySize = code.length();
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Random rand = new Random();
Graphics2D g2 = image.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// 创建颜色集合，使用java.awt包下的类
Color[] colors = new Color[5];
Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,
Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
Color.PINK, Color.YELLOW};
float[] fractions = new float[colors.length];
for (int i = 0; i < colors.length; i++) {
colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
fractions[i] = rand.nextFloat();
}
Arrays.sort(fractions);
// 设置边框色
g2.setColor(Color.GRAY);
g2.fillRect(0, 0, w, h);
Color c = getRandColor(200, 250);
// 设置背景色
g2.setColor(c);
g2.fillRect(0, 2, w, h - 4);
// 绘制干扰线
Random random = new Random();
// 设置线条的颜色
g2.setColor(getRandColor(160, 200));
for (int i = 0; i < 20; i++) {
int x = random.nextInt(w - 1);
int y = random.nextInt(h - 1);
int xl = random.nextInt(6) + 1;
int yl = random.nextInt(12) + 1;
g2.drawLine(x, y, x + xl + 40, y + yl + 20);
}
// 添加噪点
// 噪声率
float yawpRate = 0.05f;
int area = (int) (yawpRate * w * h);
for (int i = 0; i < area; i++) {
int x = random.nextInt(w);
int y = random.nextInt(h);
// 获取随机颜色
int rgb = getRandomIntColor();
image.setRGB(x, y, rgb);
}
// 添加图片扭曲
shear(g2, w, h, c);
g2.setColor(getRandColor(100, 160));
int fontSize = h - 4;
Font font = new Font("Algerian", Font.ITALIC, fontSize);
g2.setFont(font);
char[] chars = code.toCharArray();
for (int i = 0; i < verifySize; i++) {
AffineTransform affine = new AffineTransform();
affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
g2.setTransform(affine);
g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
}
g2.dispose();
ImageIO.write(image, "jpg", os);
}
/**
* 随机颜色
*
* @param fc
* @param bc
* @return
*/
private static Color getRandColor(int fc, int bc) {
if (fc > 255) {
fc = 255;
}
if (bc > 255) {
bc = 255;
}
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
private static int getRandomIntColor() {
int[] rgb = getRandomRgb();
int color = 0;
for (int c : rgb) {
color = color << 8;
color = color | c;
}
return color;
}
private static int[] getRandomRgb() {
int[] rgb = new int[3];
for (int i = 0; i < 3; i++) {
rgb[i] = random.nextInt(255);
}
return rgb;
}
private static void shear(Graphics g, int w1, int h1, Color color) {
shearX(g, w1, h1, color);
shearY(g, w1, h1, color);
}
private static void shearX(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(2);
boolean borderGap = true;
int frames = 1;
int phase = random.nextInt(2);
for (int i = 0; i < h1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(0, i, w1, 1, (int) d, 0);
if (borderGap) {
g.setColor(color);
g.drawLine((int) d, i, 0, i);
g.drawLine((int) d + w1, i, w1, i);
}
}
}
private static void shearY(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(40) + 10; // 50;
boolean borderGap = true;
int frames = 20;
int phase = 7;
for (int i = 0; i < w1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(i, 0, 1, h1, 0, (int) d);
if (borderGap) {
g.setColor(color);
g.drawLine(i, (int) d, i, 0);
g.drawLine(i, (int) d + h1, i, h1);
}
}
}
}
register.jsp（展示验证码）
<img id="checkCodeImg" src="/brand-demo/checkCodeServlet">
checkCodeServlet（生成验证码）
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 生成验证码
ServletOutputStream os = response.getOutputStream();
String checkCode = CheckCodeUtil.outputVerifyImage(100, 50, os, 4);
// 存入Session
HttpSession session = request.getSession();
session.setAttribute("checkCodeGen",checkCode);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
register.jsp（验证码“看不清”）（重置验证码）
<script>
document.getElementById("changeImg").onclick = function () {
document.getElementById("checkCodeImg").src = "/brand-demo/checkCodeServlet?"+new Date().getMilliseconds();
}
</script>
注册案例--校验验证码
registerServlet（校验验证码）
// 获取用户输入的验证码
String checkCode = request.getParameter("checkCode");
// 程序生成的验证码，从Session获取
HttpSession session = request.getSession();
String checkCodeGen = (String) session.getAttribute("checkCodeGen");
// 比对
if(!checkCodeGen.equalsIgnoreCase(checkCode)){
request.setAttribute("register_msg","验证码错误");
request.getRequestDispatcher("/register.jsp").forward(request,response);
// 不允许注册
return;
}
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