I recently installed an SSL cert on one of my sites. I have noticed that Google has now indexed both the http and https version of each page. I haven't really noticed any problem ranking wise so far, but I am conscious that a problem may occur with duplicate content.
How can I overcome this? Only a few of my pages will be using https, most of the pages on the site will be best served with just http, in fact I could get away with not using https pages at all for the time being if necessary.
A few ideas I have come across are: 301 redirects, redirect all https to http with .htaccess.
Robots.txt for the ssl pages , again using .htaccess. The problem here is that the https pages have already been indexed and I would like them to be deindexed. I am not sure if robots.txt would be sufficient because as far as I am aware robots.txt will just tell a bot not to crawl the page, but it has already been indexed.
Is there any other suggestions?
Use canonical URLs for this.
As i have already faced this problem ,Good solution will be cannonical link Google will remove your indexd https page after some time (takes week to month ).For those page where you can't put cannonical link give 301 redirect from https to http .
来源：https://stackoverflow.com/questions/10283217/http-https-dupliacte-content-google