1.学到的东西：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>login</title>
<script>
window.onload = function(){
document.getElementById("img").onclick = function(){
this.src="/day16/checkCodeServlet?time="+new Date().getTime();
}
}
</script>
<style>
div{
color: red;
}
</style>
</head>
<body>
<form action="/day16/loginServlet" method="post">
<table>
<tr>
<td>用户名</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td>验证码</td>
<td><input type="text" name="checkCode"></td>
</tr>
<tr>
<td colspan="2"><img id="img" src="/day16/checkCodeServlet"></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="登录"></td>
</tr>
</table>
</form>
<div><%=request.getAttribute("cc_error") == null ? "" : request.getAttribute("cc_error")%></div>
<div><%=request.getAttribute("login_error") == null ? "" : request.getAttribute("login_error") %></div>
</body>
</html>
package cn.itcast.servlet;
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 {
//1.设置request编码
request.setCharacterEncoding("utf-8");
//2.获取参数
String username = request.getParameter("username");
String password = request.getParameter("password");
String checkCode = request.getParameter("checkCode");
//3.先获取生成的验证码
HttpSession session = request.getSession();
String checkCode_session = (String) session.getAttribute("checkCode_session");
//删除session中存储的验证码
session.removeAttribute("checkCode_session");
//3.先判断验证码是否正确
if(checkCode_session!= null && checkCode_session.equalsIgnoreCase(checkCode)){
//忽略大小写比较
//验证码正确
//判断用户名和密码是否一致
if("zhangsan".equals(username) && "123".equals(password)){//需要调用UserDao查询数据库
//登录成功
//存储信息，用户信息
session.setAttribute("user",username);
//重定向到success.jsp
response.sendRedirect(request.getContextPath()+"/success.jsp");
}else{
//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{
//验证码不一致
//存储提示信息到request
request.setAttribute("cc_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);
}
}
2.遇到的问题：用户登录的实现
3.明日计划:继续学习JAVA WEB技术
