jsp - JSP转发和重定向的区别

Question

这个问题已经有答案了:

RequestDispatcher.forward() vs HttpServletResponse.sendRedirect() (9 个回答)

已关闭 5 年前。

请解释一下 jsp:forward 之间的区别和redirect 。
每种情况发生了什么？

Answer 1

• redirect 将响应状态设置为 302 [1]，并在 Location header 中设置新 URL，并将响应发送到浏览器。然后浏览器根据http规范，向新的url再次发出请求

• 转发完全发生在服务器上。 servlet 容器只是将相同的请求转发到目标 url，而浏览器不知道这一点。因此，在处理新 url 时，您可以使用相同的请求属性和相同的请求参数。并且浏览器不会知道 url 已更改(因为它完全发生在服务器上)

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[1]: This is an example of industry practice contradicting the standard. The HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours. However, some Web applications and frameworks use the 302 status code as if it were the 303. Source