j2ee:servlet练习短信项目，包含过滤器的使用、EL表达式和JSTL标准标签库的使用

1.过滤器的使用

package com.comm;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class MyFilter implements Filter{

@Override
public void destroy() {
// TODO Auto-generated method stub
System.out.println("-----destroy()");
}

@Override
public void doFilter(ServletRequest req, ServletResponse resp,
   FilterChain chain) throws IOException, ServletException {
  System.out.println("-----doFilter()");
  HttpServletRequest request = (HttpServletRequest)req;//封装客户端强求的是HttpServletRequest对象而不是ServletRequest，因此这里向下转型
  HttpServletResponse response = (HttpServletResponse)resp;
  HttpSession session=request.getSession();
  Object obj=session.getAttribute("u");
  List<String> path=new ArrayList<String>();
  path.add("/index.jsp");
  path.add("/userServlet");
  String p=request.getServletPath();
  //System.out.println("打印路径："+p);
  if(path.contains(p)){
   chain.doFilter(request, response);
  }else{
   if(obj!=null){
    chain.doFilter(request, response);
   }else{
    response.sendRedirect("index.jsp");
   }
  }
}

@Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
System.out.println("-----init()");
}

}

2.EL表达式和标准标签库的使用

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="com.dao.*,com.dao.impl.*,com.entity.*" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>My JSP 'msgList.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

     <link rel="stylesheet" type="text/css" href="style/style.css">


</head>

<body>
       <%
          Users u=(Users)session.getAttribute("u");
          ArrayList<Message> mlist=(ArrayList<Message>)session.getAttribute("mlist");
       %>

     <div align="center">
<%-- 用户信息 --%>
<div style="width:500px">
    当前用户${u.uname }
    <a href="userServlet?op=exit">[登出]</a>
    <a href="userServlet?op=tofasong">[给旧号码发短消息]</a>
    <a href="post2.jsp">[给新号码发短消息]</a>
</div>

<h2 align="left" style="width:600px">我的短消息</h2>

    <%-- 短消息列表 --%>
    <div align="left" style="width:600px">
    <form action="">
          <table>
          <tr>
               <th><a href="javascript:document.myform.submit()">批量删除</a></th>
               <th>内容</th>
               <th>发送者</th>
               <th>发送时间</th>
               <th>状态</th>
               <th>操作</th>
            </tr>
            <c:forEach var="b" items="${mlist}" varStatus="a">
                     <tr <c:if test="${a.index%2==0}">style="background-color: gray" </c:if>
                     <c:if test="${a.index%2!=0}"> style="background-color: #ffff00" </c:if>>
            <td><input type="checkbox" name="cbox" value="${b.mid}"/></td>
            <td>${b.mcontent}</td>
            <td>${b.sendUname}</td>
            <td>${b.mtime }</td>
            <c:if test="${b.state eq 1}">
          <td><img src="image/old.jpg"/></td>
         </c:if>
         <c:if test="${b.state==0}">
          <td><img src="image/new.jpg"/></td>
         </c:if>
          <td>
          <a href="messageServlet?op=seaByid&mid=${b.mid}">查看详情</a>
          <a href="messageServlet?op=delmessage&mid=${b.mid}">删除</a>
          </td>
           </tr>
              </c:forEach>


          </table>
    </form>



    </div>
</div>

</body>

</html>

j2ee:servlet练习短信项目，包含过滤器的使用、EL表达式和JSTL标准标签库的使用

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