清除浏览器页面缓存

比如注册是当浏览器第一次注册成功后，并进行回退到原注册页面再次修改内容并地二次提交，此时的二次提交的内容是

缓存内容，所以要将缓存内容清空后才能生效，清空缓存的方法：

Using PHP:

header("Cache-Control: no-cache, no-store, must-revalidate"); // HTTP 1.1.
header("Pragma: no-cache"); // HTTP 1.0.
header("Expires: 0"); // Proxies.

Using Java Servlet, or Node.js:

response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
response.setHeader("Pragma", "no-cache"); // HTTP 1.0.
response.setHeader("Expires", "0"); // Proxies.

Using ASP.NET:

Response.AppendHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.0.
Response.AppendHeader("Expires", "0"); // Proxies.

Using ASP:

Response.addHeader "Cache-Control", "no-cache, no-store, must-revalidate" ' HTTP 1.1.
Response.addHeader "Pragma", "no-cache" ' HTTP 1.0.
Response.addHeader "Expires", "0" ' Proxies.

Using Ruby on Rails, or Python on Flask:

response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate" # HTTP 1.1.
response.headers["Pragma"] = "no-cache" # HTTP 1.0.
response.headers["Expires"] = "0" # Proxies.

Using Google Go:

responseWriter.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate") // HTTP 1.1.
responseWriter.Header().Set("Pragma", "no-cache") // HTTP 1.0.
responseWriter.Header().Set("Expires", "0") // Proxies.

Using Apache .htaccess file:

<IfModule mod_headers.c>
    Header set Cache-Control "no-cache, no-store, must-revalidate"
    Header set Pragma "no-cache"
    Header set Expires 0
</IfModule>

Using HTML4:

<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="0" />

HTML meta tags vs HTTP response headers

根据SO上面的说法，

如果通过HTTP访问，HTTP response headers 是优先于 meta tags 的。但

是，第一次打开是通过HTTP访问的，而返回的时候是从本地读取的。

我在自己尝试的时候，发现这两个都需要设置才能清除页面表单记录。Google浏览器和 IE11测试通过，页面的记录消除。其他的浏览器未测试。（推测是因为上面的原因）

如果多次测试发现页面表单的记录还在。

但是可以保证，只要写了HTTP response headers 返回的时候一定会重新请求。

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <%  
 4 response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.  
 5 response.setHeader("Pragma", "no-cache"); // HTTP 1.0.  
 6 response.setHeader("Expires", "0"); // Proxies.  
 7 %> 
 8 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 9 <html>
10 <head>
11 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
12 <title>Insert title here</title>
13     <!-- <meta http-equiv="pragma" content="no-cache">  
14     <meta http-equiv="cache-control" content="no-cache, no-store, must-revalidate" >  
15     <meta http-equiv="expires" content="0" > --> 
16 </head>
17 <body>
18 <%  
19            long token=System.currentTimeMillis();    //产生时间戳的token
20             session.setAttribute("token",token);      
21     %>  
22 
23     <form  action="${pageContext.servletContext.contextPath }/formSubmit/submit_.action" method="post">  
24         <input type="text"  name="username"/>  <br>
25         <input type="text"  name="password"/>  <br>  
26         <input type="hidden" value="${token }" name="reqtoken"/>  <br>   <!-- 作为hidden提交 -->  
27         <input type="submit" value="提交"/>  <br>  
28     </form>  
29 </body>
30 </html>