<a href="next.jsp" rel="external nofollow" >URL 后面追加参数</a>

<jsp:include page="next.jsp"><jsp:param name="paramA" value="A"/></jsp:include> 

<jsp:forward page="next.jsp"><jsp:param name="paramA" value="B"/></jsp:forward> 

response.sendRedirect("next.jsp")

window.location = "next.jsp"

//内嵌的 java 代码
<%String paramA = request.getParameter("paramA"); %>

//如果引入了 EL
{param.paramA}

 <form action="next.jsp" method="post"> 
  <input type="text" name="paramA" value="A"> 
  <input type="hidden" name="paramB" value="B"> 
  <input type="submit" value="提交"> 
 </form> 

 <% 
  Cookie c=new Cookie("paramA","A"); 
  c.setMaxAge(60*60); //cookie 有效期1分钟
  response.addCookie(c); //将cookie 添加到 http响应中
  %>

//内嵌的 java 代码
<%
 Cookie cookie = null;
 // 获取cookies的数据,是一个数组
 Cookie[] cookies = request.getCookies();
 if(cookies != null ){
  for (int i = 0; i < cookies.length; i++){
   cookie = cookies[i];
   out.print("参数名 : " + cookie.getName());
   out.print("<br>");
   out.print("参数值: " + URLDecoder.decode(cookie.getValue(), "utf-8") +" <br>");
   out.print("------------------------------------<br>");
  }
 }else{
  out.println("<h2>没有发现 Cookie</h2>");
 }
%>

//EL 获取方式
${cookie.paramA.value}

 <%  
 session.setAttribute("paramA","A"); 
 response.sendRedirect("next.jsp"); 
 %>

//内嵌java 片段
<%=session.getAttribute("paramA") %>

//EL 获取方式
{session.paramA}