2)位于WEB-INF/目录下的资源，客户端无法直接访问，只能通过服务端转发进入
3)request对象也可用于资源的转发
request
.getRequestDispatcher("/WEB-INF/success.html")
.forward(request,response);
4)通过正则表达式验证中文：[\u4E00-\uFA29]+
5)对于重定向而言，前后的二个Request域对象不同，如果取值不到，返回"null"，不会报错 ???
java代码：
ModelBean
public class ModelBean { ???public boolean validate(String username){ ???????boolean flag = false; ???????//username.matches("[a-zA-Z0-9]+")) 用户名是数字与字母 ???????if(username!=null && username.matches("[\u4E00-\uFA29]+")){ ???????????flag = true; ???????} ???????return flag; ???}}Demo8
import java.io.IOException;import javax.servlet.RequestDispatcher;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.itcast.web.domain.ModelBean;public class Demo8 extends HttpServlet { ???//NO1 ???public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { ???????//转发到view.html页面 ???????RequestDispatcher rd = request.getRequestDispatcher("/WEB-INF/view.html"); ???????rd.forward(request,response); ???} ???//NO2 ???public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { ???????request.setCharacterEncoding("UTF-8"); ???????String username = request.getParameter("username"); ???????ModelBean mb = new ModelBean(); ???????boolean flag = mb.validate(username); ???????if(flag){ ???????????//将用户名绑定到Request域对象中 ???????????request.setAttribute("USERNAME",username); ???????????/*转发到ListServlet.java ???????????request ???????????????.getRequestDispatcher("/ListServlet") ???????????????.forward(request,response); ???????????*/ ?????????????//重定向到ListServlet.java ???????????response.sendRedirect("/day07/ListServlet"); ???????}else{ ???????????request ???????????.getRequestDispatcher("/WEB-INF/fail.html") ???????????.forward(request,response); ???????} ???}}ListServlet
import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class ListServlet extends HttpServlet { ???public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { ???????String username = (String) request.getAttribute("USERNAME"); ???????response.setContentType("text/html;charset=UTF-8"); ???????response.getWriter().write("欢迎"+username+"光临"); ???} ???public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { ???????String username = (String) request.getAttribute("USERNAME"); ???????response.setContentType("text/html;charset=UTF-8"); ???????response.getWriter().write("欢迎"+username+"光临"); ????????}}html
view.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> ?<head> ???<title>用户登录</title> ???<meta http-equiv="content-type" content="text/html; charset=UTF-8"> ?</head> ?<body> ???<form action="/day07/Demo8" method="post"> ???????<table border="1" align="center"> ???????????<caption>用户登录</caption> ???????????<tr> ???????????????<th>用户名</th> ???????????????<td><input type="text" name="username"/></td> ???????????</tr> ???????????<tr> ???????????????<td colspan="2" align="center"> ???????????????????<input type="submit" value="提交"/> ??????????????????????????? ???????????????????<input type="reset" value="重填"/> ???????????????</td> ???????????</tr> ??????????</table> ???</form> ?</body></html>sucess.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> ?<head> ???<title>用户登录</title> ???<meta http-equiv="content-type" content="text/html; charset=UTF-8"> ?</head> ?<body> ???登录成功 ???</body></html>fail.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> ?<head> ???<title>用户登录</title> ???<meta http-equiv="content-type" content="text/html; charset=UTF-8"> ?</head> ?<body> ???登录失败 ???</body></html>MVC设计模式-学习笔记
原文地址：http://blog.51cto.com/357712148/2104909