Async Request parameters & Parts

@glassfishrobot is already working on this.

Since Jun 6, 2018.

Section 9.7.2 describes a set of request attributes that contain the path values of the original request, so that they may be accessed by a servlet called as a result of a AsyncContext.dispatch(...)

However, this implies that these attributes are only set after a AsyncContext.dispatch(...), which means that they are not available to a thread that might be acting as part of a startAsync().... AsyncContext.complete() pattern.

Note that a thread cannot access the original request paths via AsyncContext.getRequest().getServletPath() because the value returned from that can be affected by forwards that happen before and/or after the startAsync call, or even a forward after an async dispatch. The path methods are inherently volatile.

I think that the ASYNC request parameters should be set when startAsync is called, so that those values are available for the entire async life cycle and not only during async dispatch.