问题
Environment: Java HotSpot(TM) 64-Bit Server VM (build 16.3-b01, mixed mode),tomcat6
When I use HttpServlet to send a html page，like this：
resp.getWriter().append(body);//"body" is a html file content,and has some \n at first
resp.addHeader(name, value);
When the codes run on Linux,the http client can not get the header that I added,but run on Windows7 it can.
I exchange order the codes,like this:
resp.addHeader(name, value);
resp.getWriter().append(body);//"body" is a html file content
then it's ok both on linux and windows.
This is why?
回答1:
Headers cannot be written once the response is committed. Response is said to be committed if some part of the response is written to the client. There are several reasons why the response gets committed due to several reasons.
Reasons for response getting committed
来源：https://stackoverflow.com/questions/23190944/httpservletresponse-lose-header-if-write-body-before-addheader