日期:2014-05-17  浏览次数:20681 次

jsp求助 代码运行一片空白
HTML code
<%@ page language="java" import="java.util.*" contentType="text/html;
 charset=UTF-8" pageEncoding="UTF-8" errorPage="login.jsp"%>
<%
    request.setCharacterEncoding("UTF-8");
    
    String username = "";
    int visitTimes = 0;
    Cookie[] cookies = request.getCookies();
    for(int i=0; cookies!=null&&i<cookies.length;i++) {
        Cookie cookie = cookies[i];
        if("username".equals(cookie.getName())) {
            username = cookie.getValue();
        }
        else if("visitTimes".equals(cookie.getName())) {
            visitTimes = Integer.parseInt(cookie.getValue());
        }
    }
    if(username == null || username.trim().equals("")) {
        throw new Exception("未登录,请先登录");
    }
    
    Cookie visitTimesCookie  =new Cookie("visitTimes", Integer.toString(++visitTimes));
    response.addCookie(visitTimesCookie);
 %>
<html>
  <head>  
  </head>
  <body>
  <div align="center">
      <fieldset>
          <legend>登录信息</legend>
          <form action="login.jsp" method="post"></form>
              <table>
                  <tr>
                      <td>你的帐号:</td>
                      <td><%=username%></td>
                  </tr>
                  <tr>
                      <td>登录次数</td>
                      <td><%=visitTimes %></td>
                  </tr>
                  <tr>
                      <td></td>
                      <td>
                          <input type="button" value="刷新" onclick="location='
                          <%= request.getRequestURI()%>?ts='+new Date().getTime();" class="button">
                      </td>
                  </tr>
              </table>
      </fieldset>
  </div>
  </body>
</html>



------解决方案--------------------
我知道为啥了,你第一句话,把这个删除掉 “errorPage="login.jsp"”,出错又强制回登录界面了。

另外这段代码修改下:
if(username == null || username.trim().equals("")) {
System.err.println("未登录,请先登录");
}
就应该能看到了。