jsp中使用cookie时报错……

清疚 2022-12-25 02:49 162阅读 0赞

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今天在看jsp中的cookie时，遇到一个比较麻烦的问题。

关键代码如下：

登录页面：login.jsp

处理登录业务的doLogin.jsp

<%@page import="java.net.URLEncoder"%>
    <%@page import="org.dao.impl.StudentDaoImpl"%>
    <%@page import="org.dao.IStudentDao"%>
    <%@page import="org.entity.Student"%>
    <%@page import="org.service.impl.StudentServiceImpl"%>
    <%@page import="org.service.IStudentService"%>
    <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
      //创建Service的对象
      IStudentService studentService = new StudentServiceImpl();
      
      //解决乱码的问题
      request.setCharacterEncoding("utf-8");
      //获取表单的值
      String sname = request.getParameter("sname");
      String spass = request.getParameter("spass");
      //调用service的方法进行登陆
      Student stu = studentService.login(sname, spass);
      if(stu.getSid()!=0){
        //登陆成功
        //将用户名放入到Cookie里面
         Cookie scook = new Cookie("sname",sname);
        response.addCookie(scook); 
        
        //将登陆信息放在Session中
        //session.setAttribute("sname",sname);
        request.getRequestDispatcher("index.jsp")
              .forward(request,response);
      }
      
      
     %>

登录成功跳转到的页面：index.jsp

<body>
          <h1>欢迎进入学生管理系统</h1>
        <%
              Cookie cookie[] = request.getCookies();
              for(int i=0;i<cookie.length;i++){
                Cookie cook = cookie[i];
                if(cook.getName().equals("sname")){
                  %> 
                  你好：<%=cook.getValue()%>
                  
                  <%
                }
              }
           %> 
           
           <%-- <%
           String sname =(String)session.getAttribute("sname");
               if(sname==null){
                 response.sendRedirect("login.jsp");
               }
            %>
            <%=sname %> --%>
      </body>

代码都写的没问题，就是报错：

**ava.lang.IllegalArgumentException: Control character in cookie value or attribute.**

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后来用英文的昵称登录，正常显示：

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看来就是中文编码的问题了，在网上查了查，确实是编码的问题，只需要在放置cookie的时候，设置编码格式为UTF-8，并且在显示时，设置编码格式也为UTF-8，问题完美解决，修改过后的代码如下：

登录业务处理：doLogin.jsp

Cookie scook = new Cookie("sname",URLEncoder.encode(sname,"UTF-8"));

登录成功:index.jsp

<%
              Cookie cookie[] = request.getCookies();
              for(int i=0;i<cookie.length;i++){
                Cookie cook = cookie[i];
                if(cook.getName().equals("sname")){
                  %> 
                  你好：<%=URLDecoder.decode(cook.getValue(),"UTF-8")%>
                  
                  <%
                }
              }
           %>

切记切记，在讲中文字符往Cookie中放的时候，一定要设置编码格式。

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