一：注册页面：regist.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
Insert title here
二：.验证码servlet：CheckCodeServlet.java
完成页面显示验证码的效果：
package com.itcode.view;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CheckCodeServlet extends HttpServlet {
// ctrl + shift +X 变大写 ----------- Y
private final int WIDTH = 120;
private final int HEIGHT = 30;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setHeader("cache-control", "no-cache");
response.setHeader("pragma", "no-cache");
response.setDateHeader("expires", -1);
// 1.在内存中构建出一张 图片
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics = (Graphics2D) image.getGraphics();
// 将 背景设置 为 白色 .
graphics.setColor(Color.WHITE);
graphics.fillRect(0, 0, WIDTH, HEIGHT);
// 状态机
// 画 矩形 . 之前 由于已经设置 过 颜色 ,就相当于 维护了 一个状态机, 所以 你需要 再次调用 setCorlor , 否则 就看不到 你 画 的矩形了 .
graphics.setColor(Color.BLUE);
graphics.drawRect(0, 0, WIDTH-1, HEIGHT-1);
// 准备好 要 使用的 汉字.
// String base ="ABCDEFGHIJKLMNOPQRST";
String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
Random rand = new Random();
// 设置颜色
graphics.setColor(Color.RED);
// 设置 字体
graphics.setFont(new Font("宋体",Font.BOLD,18));
StringBuilder sb = new StringBuilder();
int m =10;
// 在for循环中 将 汉字画上去
for (int i = 0; i < 4; i++) {
int index = rand.nextInt(base.length());
char charAt = base.charAt(index);
// -30 -- 30
int jiaodu = rand.nextInt(60) -30;
double theta = jiaodu*Math.PI/180;
graphics.rotate(theta, m, 15);
graphics.drawString(charAt +"", m, 20);
sb.append(charAt);
graphics.rotate(-theta, m, 15);
m+=25;
}
// 画 4 条线
graphics.setColor(Color.GREEN);
for (int i = 0; i < 4; i++) {
int x1 = rand.nextInt(WIDTH);
int x2 = rand.nextInt(WIDTH);
int y1 = rand.nextInt(HEIGHT);
int y2 = rand.nextInt(HEIGHT);
// 调用 该方法, 划线 两点 确定 一条直线 . 需要 4 个点
graphics.drawLine(x1, y1, x2, y2);
}
request.getSession().setAttribute("checkcode_session", sb.toString());
// 释放 graphics 对象, 调用 该方法之后 graphic 就不能再使用了 .
graphics.dispose();
// 通过该 imageIO 将 内存中构建好的 图片 与 response的流 给 关联起来.
ImageIO.write(image, "png", response.getOutputStream());
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
三：处理注册的servlet：RegistServlet.java
package com.itcode.controller;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.beanutils.BeanUtils;
import com.itcode.model.User;
import com.itcode.model.UserOperator;
public class RegistServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
response.getWriter().println("成功注册！");
User user = new User();
try {
BeanUtils.populate(user, request.getParameterMap());
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
UserOperator userOperator = new UserOperator();
int UserFeedBack = userOperator.regist(user);
switch (UserFeedBack) {
case UserOperator.USERNAME_EXIST:
request.setAttribute("message", "用户名已经在在！");
// response.sendRedirect("/regist.jsp");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
break;
case UserOperator.EMAIL_EXIST:
request.setAttribute("message", "邮箱已经被注册使用！");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
break;
case UserOperator.SUCCESS:
response.sendRedirect("/user/login.jsp");//注意此时的路径与上面的路径的区别！
break;
default:
break;
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
四：RegistServlet的所需要的类：
User类：
package com.itcode.model;
public class User {
private String username;
private String password;
private String email;
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 getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
UserOperator类：
package com.itcode.model;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
public class UserOperator {
public static final int USERNAME_EXIST=1;
public static final int EMAIL_EXIST=2;
public static final int SUCCESS =3;
/**
* 检验注册用户数据的合法性，并返回相应的状态码。
* @param user
* @return int userFeedBack
*/
public int regist(User user){
SAXReader saxReader = new SAXReader();
Document document =null;
try {
document = saxReader.read("d://users.xml");
} catch (DocumentException e) {
e.printStackTrace();
}
//1.得到文件的根标签:users
Element rootElement = document.getRootElement();
//2.由根标签得到所有的用户标签：user
List UserElements = rootElement.elements("user");
//3.遍历每个user,以便确保新注册的username,email是未使用过的
for (Element element : UserElements) {
if(element.elementText("username").equals(user.getUsername()))
return USERNAME_EXIST;
if(element.elementText("email").equals(user.getEmail()))
return EMAIL_EXIST;
}
//4.到此说明用户名，邮箱都是未使用过的，就将其加入文件，
//4.1创建用户根标签：user
Element userEle = DocumentHelper.createElement("user");
//4.2创建username标签,并赋值
Element usernameEle = DocumentHelper.createElement("username");
usernameEle.setText(user.getUsername());
//4.3创建password标签,并赋值
Element passwordEle = DocumentHelper.createElement("password");
passwordEle.setText(user.getPassword());
//4.3创建email标签,并赋值
Element emailEle = DocumentHelper.createElement("email");
emailEle.setText(user.getEmail());
//4.4将创建的各个标签加入到user根标签中
userEle.add(usernameEle);
userEle.add(passwordEle);
userEle.add(emailEle);
//4.5将创建的user标签加入到根标签users中：
rootElement.add(userEle);
//5.将上述内存中的文件写回到原文件中：
XMLWriter xmlWriter =null;
OutputFormat format = OutputFormat.createPrettyPrint();
try {
xmlWriter = new XMLWriter(new FileOutputStream("d:\\users.xml"),format);
xmlWriter.write(document);
xmlWriter.close();
}catch (Exception e) {
e.printStackTrace();
}
return SUCCESS;
}
public User login(User user) {
SAXReader saxReader = new SAXReader();
Document document = null;
try {
document = saxReader.read("d://users.xml");
} catch (Exception e) {
e.printStackTrace();
}
Element rootElement = document.getRootElement();
List elements = rootElement.elements("user");
for (Element element : elements) {//如果存在,将此用户，如果不存在，返回空，
if(element.elementText("username").equals(user.getUsername()) &&
element.elementText("password").equals(user.getPassword())){
return user;
}
}
return null;
}
}
五：登陆页面：login.jsp:
提供让用户填写登陆信息的页面
将用户填写的信息发给LoginServlet：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
Insert title here
${message }
<%="fuck you, plealse login!" %>
六：LoginServlet,查看用户登陆时所填写的信息是否与数据库文件中的相应数据符合，
若符合，则显示登陆成功，若不符合，则请求转发到登陆页面：
package com.itcode.controller;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.beanutils.BeanUtils;
import com.itcode.model.User;
import com.itcode.model.UserOperator;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
User user = new User();
try {
BeanUtils.populate(user, request.getParameterMap());
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
UserOperator userOperator = new UserOperator();
User existUser = userOperator.login(user);
if(existUser == null){
response.getWriter().println("用户名或密码不正确，请重新输入！");
request.getRequestDispatcher("/login.jsp").forward(request, response);
}else{//登陆成功后，跳转到首页。在首 页要判断用户是否已经登陆
request.getSession().setAttribute("existUser",existUser);
if("on".equals(request.getParameter("remember"))){
//1.将用户名写进cookie
// Cookie usernameCookie = new Cookie("username",request.getParameter("username"));
Cookie usernameCookie = new Cookie("username",existUser.getUsername());
usernameCookie.setMaxAge(60*12);
usernameCookie.setPath("/");
response.addCookie(usernameCookie);
System.out.println("-----------22----------------");
//2.将密码写进cookie
// Cookie passwordCookie = new Cookie("password",request.getParameter("password"));
Cookie passwordCookie = new Cookie("password",existUser.getPassword());
passwordCookie.setMaxAge(60*12);
passwordCookie.setPath("/");
response.addCookie(passwordCookie);
System.out.println("-----------44----------------");
}
response.sendRedirect("/user/index.jsp");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
七：注销成功的实现：
在登录成功后的页面写个注销的超链接，链接到注销Servlet，LogoutServlet.java
package com.itcode.controller;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// request.getSession().removeAttribute("existUser");
request.getSession().invalidate();
response.getWriter().println("fuck you have logout!");
response.sendRedirect("/user/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
八：为了显示效果，写个首页：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
Insert title here
这是首页
你好，你还没有登陆！
去登陆
去注册
${existUser.username },你好，你已经成功登陆！
去注销
