Let the page not cache, automatically refresh

Purpose: to keep the page from being cached and automatically refreshed.

problem

The front end has made a timer to get data from the back end in real time, and the data is stuffed into the jsp at the back end.
After I returned to this page from another page, the page fetched data from the cache, which caused a timing error.

solve

1. Add meta tag setting to not use cache

<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" />

2. Add refresh operation

window.onpageshow = function(event) {
	if (event.persisted || window.performance && window.performance.navigation.type == 2) {//页面是从缓存中获取的数据||是通过浏览器后退来到该页面
		window.location.reload();
	}
}

• window.performance.navigation.type == 2 Return to this page by going back
• event.persisted is true when getting data from the cache, otherwise it is false

expand

window.performance

• The navigation field counts some data related to web page navigation:

• redirectCount : the number of redirects (read-only), but this interface has the same-origin policy restriction, that is, only the same-origin redirects can be detected;

• The return value of type should be one of 0,1,2. Corresponding to three enumeration values:

  • 0: TYPE_NAVIGATE (Users access the page through conventional navigation methods, such as clicking a link, or general get method)
  • 1: TYPE_RELOAD (Users access the page by refreshing, including JS calling the refresh interface, etc.)
  • 2: TYPE_BACK_FORWARD (Users access this page through the back button)

Link to this article: https://blog.csdn.net/qq_39903567/article/details/114981256