java - [cookie跨域问题]cookie.setDomainName()不起作用？

Question

为了做一个免登陆，需要回写非当前域名的cookie，使用cookie.setDomain(".test.com"); response.addCookie(cookie);不起作用，请教下为什么？

Answer 1

If it is a second-level domain name of the current domain name, it seems to be possible, otherwise it is not supported. This is a requirement in the security specification, and browser implementers will not do this unless you make a browser yourself.

Answer 2

Set up on your frontend page

document.domain = 'test.cn'; //这样就能读取到一级域名下(不同的二级域名也能读取的到)得所有cookie

Pay attention to whether different cookie-names are set in the background

Answer 3

HTTP specification constraints prohibit cross-domain reading and writing of cookies. Although the browser received the cookie sent by the server (which is illegal), it simply ignored it.