Jetty 12 inserted handler in ee10 servlet context

[gregw]

This PR refactors the ee10 handing of servlet API request and response objects:

• The ServletContextHandler matches the request to a servlet and creates a one time only ServletContextRequest and a ServletContextResponse
• A reusable ServletChannel object with all the heavy weight HttpInput and HttpOutput object is associated with the ServletContextRequest and ServletContextResponse.
• Once the handling reaches the ServletHandler, the possibly wrapped request, response and callback are associated with the ServletChannel before handling.
• Were possible the ServletApiRequest and ServletApiResponse use the possibly wrapped request/response

I have added tests to check that GzipHandler can now be nested inside of an EE10 context.

[janbartel]

@gregw can you edit the initial post to include a sentence or two on the motivation for the PR?

[janbartel]

This is a trivial javadoc error. However, it should be fixed. Also, for a more thorough review, I think we need a hangout.

[lorban]

1st review pass

[gregw]

@janbartel @lorban @lachlan-roberts I've now added ServletRequestInfo and ServletResponseInfo interfaces, which are how the ServletApiRequest/ServletApiResponse communicate with the ServletContextRequest/ServletResponse.

[lorban]

LGTM besides a few nits.

[gregw]

@janbartel @lorban @lachlan-roberts I think the test failure is a flake. So can I get a review on this before tonight's meeting?

[janbartel]

A bit of an oddity with the ServletRequestInfo.getServletContextRequest() method, but other than that, +1.

[gregw]

@janbartel @lachlan-roberts @lorban sorry, but after that last little tweak, I need a review from at least 1 of you again

[grgrzybek]

@gregw I can't track the exact part of 0b1c28a, but I think it started causing NPE in some special case.

My servlet is invoked with /gateway/x?what=include&where=/:

String what = req.getParameter("what");
String where = req.getParameter("where");
switch (what) {
	case "redirect":
		resp.sendRedirect(where);
		return;
	case "forward":
		// we can't send anything when forwarding
		req.getRequestDispatcher(where).forward(req, resp);
		return;
	case "include":
		resp.getWriter().print(">>>");
		req.getRequestDispatcher(where).include(req, resp);
		resp.getWriter().print("<<<");
		return;
	default:
}

org.eclipse.jetty.ee10.servlet.ServletApiResponse#getWriter() calls:

String encoding = getServletResponseInfo().getCharacterEncoding(true);

org.eclipse.jetty.ee10.servlet.ServletContextResponse#getCharacterEncoding(boolean) calls:

if (setContentType)
    setCharacterEncoding(encoding, EncodingFrom.DEFAULT);

so org.eclipse.jetty.ee10.servlet.ServletContextResponse#_characterEncoding is set to iso-8859-1.
Because the forward is for /, default servlet is involved (because I need to test welcome files).

org.eclipse.jetty.ee10.servlet.DefaultServlet#doGet() has this fragment:

if (contextResponse != null)
{
    String characterEncoding = contextResponse.getRawCharacterEncoding();
    if (characterEncoding != null)
        content = new ForcedCharacterEncodingHttpContent(content, characterEncoding);
}

and the constructor is:

public ForcedCharacterEncodingHttpContent(HttpContent content, String characterEncoding)
{
    super(content);
    this.characterEncoding = characterEncoding;
    String mimeType = content.getContentTypeValue();
    int idx = mimeType.indexOf(";charset");
    if (idx >= 0)
        mimeType = mimeType.substring(0, idx);
    this.contentType = mimeType + ";charset=" + this.characterEncoding;
}

the content is:

content = {org.ops4j.pax.web.service.jetty.internal.web.DefaultServlet$UnknownLengthHttpContent@4857} "UnknownLengthHttpContent@c898d8f[CompressedFormatsHttpContent@1c61db46[ResourceHttpContent@471a9af8{r=file:/data/sources/github.com/ops4j/org.ops4j.pax.web-jakarta-new/pax-web-jetty/target/b1/,ct=null}]]"
 _delegate: org.eclipse.jetty.http.content.HttpContent  = {org.eclipse.jetty.http.content.PreCompressedHttpContentFactory$CompressedFormatsHttpContent@4919} "CompressedFormatsHttpContent@1c61db46[ResourceHttpContent@471a9af8{r=file:/data/sources/github.com/ops4j/org.ops4j.pax.web-jakarta-new/pax-web-jetty/target/b1/,ct=null}]"
  _delegate: org.eclipse.jetty.http.content.HttpContent  = {org.eclipse.jetty.http.content.ResourceHttpContent@4922} "ResourceHttpContent@471a9af8{r=file:/data/sources/github.com/ops4j/org.ops4j.pax.web-jakarta-new/pax-web-jetty/target/b1/,ct=null}"
   _contentType: java.lang.String  = null
   _etag: org.eclipse.jetty.http.HttpField  = {org.eclipse.jetty.http.PreEncodedHttpField@4925} "ETag: W/"///+d0tLiXs/////73HTsQ""
   _path: java.nio.file.Path  = {sun.nio.fs.UnixPath@4924} "/data/sources/github.com/ops4j/org.ops4j.pax.web-jakarta-new/pax-web-jetty/target/b1"
   _resource: org.eclipse.jetty.util.resource.Resource  = {org.eclipse.jetty.util.resource.PathResource@4749} "file:/data/sources/github.com/ops4j/org.ops4j.pax.web-jakarta-new/pax-web-jetty/target/b1/"
  compressedFormats: java.util.Set  = {java.util.HashSet@4921}  size = 0

the underlying resource is directory, so the extension is * and the resulting content type is null.

so I'm getting NullPointerException.

My test you can run (without bothering with OSGi stuff) is https://github.com/ops4j/org.ops4j.pax.web/blob/1b26a2f8ea394d696a6780ff0fa92b2613019dff/pax-web-jetty/src/test/java/org/ops4j/pax/web/service/jetty/internal/UnifiedJettyTest.java#L361