1依据index.jsp我们首先制定了注册的功能，当点击注册button什么时候。超链接到注册页面。下面是一个注册jsp页
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<script type="text/javascript">
function changeImage(image){
image.src=image.src+"?time"+new Date().getTime();
}
</script>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body style="text-align: center">
<h1>我的站点_注冊</h1>
<font color="red">${msg }</font>
<form action="${pageContext.request.contextPath }/servlet/RegistServlet" method="post">
<table border="1" cellspacing="0" align="center">
<tr>
<td>用户名</td>
<td><input type="text" name="username" value="${param.username }"/></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password"/></td>
</tr>
<tr>
<td>确认密码</td>
<td><input type="password" name="password2"/></td>
</tr>
<tr>
<td>昵称</td>
<td><input type="text" name="nickname" value="${param.nickname }"/></td>
</tr>
<tr>
<td>邮箱</td>
<td><input type="text" name="email" value="${param.email }"/></td>
</tr>
<tr>
<td>验证码</td>
<td><input type="text" name="valistr" /></td>
</tr>
<tr>
<td><input type="submit" value="注冊" /></td>
<td><img src="${pageContext.request.contextPath }/servlet/ValiImage" style="cursor: pointer" onclick="changeImage(this)"/></td>
</tr>
</table>
</form>
</body>
</html>
执行界面示意图：
2.完毕验证码的功能建立ValiImage的servlet的类,把字符串保存到session域中，为了一会在RegistServlet中跟用户输入的验证码进行比較
package cn.itheima.web;
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 ValiImage extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//告知浏览器不缓存
response.setDateHeader("Expires", -1);
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");
int height=30;
int width=130;
//1.得到内存中的图片
BufferedImage image=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//2.得到画布
Graphics2D g = (Graphics2D) image.getGraphics();
//3.填充背景色
g.setColor(Color.LIGHT_GRAY);
g.fillRect(0, 0, width, height);
//4.画一个矩形
g.setColor(Color.black);
g.drawRect(0, 0, width-1, height-1);
//5.随机斜线
for(int i=0;i<4;i++){
g.setColor(Color.RED);
g.drawLine(randNum(0,width), randNum(0,height), randNum(0,width), randNum(0,height));
}
//6.随机写一个汉字
String base = "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";
StringBuffer buffer=new StringBuffer();
for(int i=0;i<4;i++){
g.setColor(Color.black);
int r=randNum(-45, 45);
g.rotate(1.0*r/180*Math.PI, 5+30*i, 21);//旋转ת
g.setFont(new Font("red", Font.BOLD, 15));
String s=base.charAt(randNum(0, base.length()-1))+"";
g.drawString(s, 5+30*i, 21);
buffer.append(s);
g.rotate(1.0*-r/180*Math.PI, 5+30*i, 21);//旋转的是画布，因此旋转完，要归位
}
request.getSession().setAttribute("valistr", buffer.toString());
System.out.println(buffer.toString());
//将指定格式的文件输出到response缓冲区
ImageIO.write(image, "jpg", response.getOutputStream());
}
//随机产生begin--end 之间的数字
public int randNum(int begin,int end){
Random rand=new Random();
return rand.nextInt(end-begin)+begin;//5-10 10-5=5 5+5=10
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
3.建立RegistServlet实现对应的功能
package cn.itheima.web;
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 cn.itheima.domain.User;
import cn.itheima.exception.MsgException;
import cn.itheima.service.UserSevice;
import com.sun.org.apache.commons.beanutils.BeanUtils;
public class RegistServlet extends HttpServlet {
UserSevice service = new UserSevice();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
// 1.验证验证码
String valistr = request.getParameter("valistr");
String valistr2 = (String) request.getSession().getAttribute(
"valistr");
if (valistr == null || valistr2 == null ||!valistr.equals(valistr2)) {
request.setAttribute("msg", "验证码不对");
request.getRequestDispatcher("/regist.jsp").forward(request,
response);
return;
}
// 2.封装数据校验数据
User user = new User();
BeanUtils.populate(user, request.getParameterMap());
user.check();
// 3.加入到数据库中
service.registUser(user);
request.getSession().setAttribute("user", user);//登陆
// 4.3秒后跳转到主页
response.getWriter().write("恭喜您注冊成功！三秒后跳转到主页");
response.setHeader("refresh", "3;url=" + request.getContextPath()
+ "/index.jsp");
} catch (MsgException e) {
request.setAttribute("msg", e.getMessage());
request.getRequestDispatcher("/regist.jsp").forward(request, response);
return;
}catch (Exception e) {
e.printStackTrace();
throw new RuntimeException();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
假设抛出异常。就走catch中的代码块，将msg放到request域中，等到回到regist.jsp中进行友好的提示。假设成功注冊，那么就把用户放到session域中
执行界面：
4.依据index,jsp完毕注销的功能，LogoutServlet然后重定向到主页。
package cn.itheima.web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.PageContext;
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
if(request.getSession(false)!=null&&request.getSession().getAttribute("user")!=null){
request.getSession().invalidate();
}
response.sendRedirect(request.getContextPath()+"/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
执行结果示意图：
5.完毕登录功能建立login.jsp
<%@page import="java.net.URLDecoder"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://www.itheima.com/simple/mytag" prefix="s" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<div align="center">
<h1>我的站点_登陆</h1>
<font color="red">${msg }</font>
<hr>
<form action="${pageContext.request.contextPath}/servlet/LoginSevlet" method="post">
<table border="1">
<tr>
<td>username</td>
<td><input type="text" name="username" value='<s:decode encoding="utf-8" str="${cookie.remname.value}"/>'/></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password"/></td>
</tr>
<tr>
<td><input type="submit" value="登录"/></td>
<td><input type="checkbox" name="remname" value="OK" />记住username</td>
</tr>
</table>
</form>
</div>
</body>
</html>
执行界面示意图；
5.LoginSevlet
package cn.itheima.web;
import java.io.IOException;
import java.net.URLEncoder;
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 javax.servlet.jsp.PageContext;
import cn.itheima.domain.User;
import cn.itheima.service.UserSevice;
public class LoginSevlet extends HttpServlet {
UserSevice service=new UserSevice();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//1.得到username与password
String username = request.getParameter("username");
String password=request.getParameter("password");
String OK=request.getParameter("remname");
//2.跟数据库的惊醒比較推断
User user=service.isUser(username, password);
if(user==null){
//3.不匹配,就提醒
request.setAttribute("msg", "username或密码不对！");
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
}else{
//4.找到用户。重定向到index.jsp
request.getSession().setAttribute("user", user);
if("OK".equals(OK)){
//用户须要记住username
Cookie c=new Cookie("remname",URLEncoder.encode(user.getUsername(), "utf-8"));
c.setPath(request.getContextPath());
c.setMaxAge(3600*24*30);
response.addCookie(c);
}else{
//假设用户没有勾选记住username则删除记住username的cookie
Cookie c = new Cookie("remname","");
c.setPath(request.getContextPath());
c.setMaxAge(0);
response.addCookie(c);
}
}
response.sendRedirect(request.getContextPath()+"/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
Cookie是为了实现记住username的操作。
6.由于加入Cookie的时候有中文乱码的问题。因此须要url编码和解码的操作....自己定义标签完毕。
package cn.itheima.utils;
import java.io.IOException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.SimpleTagSupport;
public class SimpleURL extends SimpleTagSupport{
private String str;
private String encoding;
public void setStr(String str) {
this.str = str;
}
public void setEncoding(String encoding) {
this.encoding = encoding;
}
@Override
public void doTag() throws JspException, IOException {
String decode = URLDecoder.decode(str, encoding == null ? "UTF-8" : encoding);
getJspContext().getOut().write(decode);
}
}
tld文件：
<?xml version="1.0" encoding="UTF-8"?> <taglib version="2.0" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"> <tlib-version>1.0</tlib-version> <short-name>s</short-name> <uri>http://www.itheima.com/simple/mytag</uri> <tag> <name>decode</name> <tag-class>cn.itheima.utils.SimpleURL</tag-class> <body-content>empty</body-content> <attribute> <name>str</name> <required>true</required> <rtexprvalue>true</rtexprvalue> <type>java.lang.String</type> </attribute> <attribute> <name>encoding</name> <required>true</required> <rtexprvalue>true</rtexprvalue> <type>java.lang.String</type> </attribute> </tag> </taglib>