这是html重定向方法，它的工作，但不是最好的。

 <meta http-equiv="Refresh" content="0;URL=https://www.example.com" />

PHP方法

<?php
function redirectTohttps() {
    if ($_SERVER['HTTPS']!="on") {
        $redirect= "https://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
        header("Location:$redirect"); 
    } 
}
?>

.htaccess approch

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

抄袭: www.letuslook.org

Not only can you do this in your .htaccess file, you should be doing this period. You will also want to follow the steps here to get your site listed on the HSTS preload list after you implement this redirect so that any requests to the insecure http version of your website never make it past the user agent. Instead, the user agent checks the requested URI against a baked in list of https only websites and, if the requested URI is on that list, changes the protocol from http to https before transmitting the request to the server. Therefore, the insecure request never makes it out into the wild and never hits the server. Eventually when the internet changes over to https only the HSTS preload list will not be needed. Until then, every site should be using it.

为了执行重定向，我们需要启用重写引擎，然后将所有流量从http端口80重定向到https。

RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://yourwebsite.tld/$1 [L,R=301]

经过多次尝试，考虑没有www和有www，这是可行的

RewriteEngine on
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} (www\.)?yourdomain.com
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

 Redirect 301 / https://example.com/

(当上面的答案都没用的时候，对我来说是有效的)

奖金:

ServerAlias www.example.com example.com

(固定https://www.example.com未找到)

这个问题的另一个优势是当负载均衡器开始发挥作用时。

情况如下: -从浏览器到负载均衡器的流量，以及返回，是(应该)HTTPS —负载均衡器与实际WebServer之间的流量为HTTP协议。

因此，PHP或Apache中的所有服务器请求变量都显示连接只是HTTP。服务器上的HTTP和HTTPS目录是相同的。

已批准答案中的重写条件不工作。 它要么是循环，要么就是不起作用。

问题是:如何让它在负载均衡器上工作。

(或者负载均衡器配置错误。这就是我所希望的，因为这样我就可以把问题转移到网络托管公司:-))

如果你正在使用Apache, mod_rewrite是最简单的解决方案，网上有很多关于如何做到这一点的文档。例如:http://www.askapache.com/htaccess/http-https-rewriterule-redirect.html