HttpServletResponse＃sendError（）是否会抛出IOException吗？

Question

The doc explains that the HttpServletResponse#sendError() method throws an IOException if an input or output exception occurs ( DRY ;).

I couldn't find any scenario that makes this method throw that exception, is there any?

Answer 1

HTTP is sent over TCP so you can safely assume that somewhere in the underlying HttpServletRequest and HttpServletResponse there is a SocketInputStream and a SocketOutputStream .

If a user closes their browser or the network goes down client-side or server-side, then the server won't be able to receive requests or send responses. If the disconnection happens while the server was in the process of sendError() , then an IOException will occur while writing to the SocketOutputStream .