FULL PRODUCT VERSION :
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) Client VM (build 25.45-b02, mixed mode)

A DESCRIPTION OF THE PROBLEM :
The HttpURLConnection's getHeaderFields method returns combined values in lists in a headers map. The values in the list of a particular header field are always in reversed order to the original http response. As the order of the header values are important in some scenario (see http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2), JRE should keep the original order of the values.

For example, the server returns the following response:
HTTP/1.1 200 OK
X-Powered-By: Servlet/3.0
Content-Type: text/plain; charset=UTF-8
Content-Language: en-US
MyHeader: value1
MyHeader: value2
MyHeader: value3
Transfer-Encoding: chunked
Date: Sat, 09 May 2015 00:27:44 GMT
Expires: Thu, 01 Dec 1994 16:00:00 GMT

When I use getHeaderFields and fetch the value of field "MyHeader", the expected value list would be
["value1", "value2", "value3"]

However what I get is always like the following, which does not honor the original reponse.
["value3", "value2", "value1"]


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
You need to create an http server that returns headers with same name, such as a server that return the following response:
HTTP/1.1 200 OK
X-Powered-By: Servlet/3.0
Content-Type: text/plain; charset=UTF-8
Content-Language: en-US
MyHeader: value1
MyHeader: value2
MyHeader: value3
Transfer-Encoding: chunked
Date: Sat, 09 May 2015 00:27:44 GMT
Expires: Thu, 01 Dec 1994 16:00:00 GMT

Then write a java program to connect to the server using HttpURLConnection, and use getHeaderFields the retrieve and print out all the headers and the combined values.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The of the the values in the list of a particular field should honor the original response, such as
["value1", "value2", "value3"]
ACTUAL -
The values are always in reversed order, like
["value3", "value2", "value1"]

REPRODUCIBILITY :
This bug can be reproduced always.