Mimes trait detects the wrong MIME type

[helfper]

Mimes trait seems to always return application/octet-stream as MIME type.

Currently:

scala> MimeTypes.mimeType("test.html")
res0: String = application/octet-stream

Expected:

scala> MimeTypes.mimeType("test.html")
res0: String = text/html

Problem:

mimeUtil is a definition instead of a variable. Every time mimeUtil is used it creates a brand new instance of MimeUtil2 and looses the MimeDetector registrations.

scalatra/core/src/main/scala/org/scalatra/util/Mimes.scala

Lines 38 to 40 in 0474fb3

	protected[this] def mimeUtil: MimeUtil2 = new MimeUtil2()
	quiet { mimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.MagicMimeMimeDetector") }
	quiet { mimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.ExtensionMimeDetector") }

Solution:

Make mimeUtil a val instead of def in the trait org.scalatra.util.Mimes

---

Unfortunately, that's not the end of the story. Even with that fix, Mimes returns the wrong MIME type for CSS files.

scala> MimeTypes.mimeType("test.css")
res1: String = application/x-pointplus

Now the problem is coming from eu.medsea.mimeutil library, which has both application/x-pointplus and text/css MIME types associated with the extension .css, and will pick one of them mostly randomly (both MIME types end up inside a HashSet at some point, so it's not guaranteed which one will come out first). This, from my point of view, makes this library unfit for purpose.

Other projects have already moved away from that library, being Apache Marmotta one of them that chose Apache Tika as an alternative (https://git-wip-us.apache.org/repos/asf?p=marmotta.git;a=commitdiff;h=f89f61f2128fcb70db885b31b42077782ad411a6), and it seems it's a quite reliable library.

scala> tika = new org.apache.tika.Tika
tika: org.apache.tika.Tika = Apache Tika 1.18

scala> tika.detect("test.html")
res2: String = text/html

scala> tika.detect("test.css")
res3: String = text/css

[magnolia-k]

Since Mines has neither test nor document, should it be better to deprecated and recommend using Files.probeContentType?

[helfper]

I'm fine with deprecating and eventually removing it, but it's currently being used in ScalatraBase in a way that is not covered by Files.probeContentType AFAIK:

scalatra/core/src/main/scala/org/scalatra/ScalatraBase.scala

Lines 288 to 290 in c7f214d

	case bytes: Array[Byte] => MimeTypes(bytes)
	case is: java.io.InputStream => MimeTypes(is)
	case file: File => MimeTypes(file)

In that case, the Content-Type auto-inference feature would have to be removed (which I believe never worked properly anyway).

[magnolia-k]

It may be possible to use 'java.net.URLConnection.guessContentTypeFromStream'

[magnolia-k]

I will organize it a little more and write a PR

[magnolia-k]

I created PR to modify MIME Type guess against file path to use URLConnection.guessContentTypeFromName

This makes it possible to add an arbitrary MIME Type on the user code side.

It is good to refer to the following blog

https://thilosdevblog.wordpress.com/2011/06/27/mime-types-in-java/

#836

[magnolia-k]

Added MIME type customization example to the test

03b0fbd

[magnolia-k]

Oh, I will fix it because the test passed by me does not go through Travis. PR will close.

[magnolia-k]

#839

[takezoe]

Can I close this issue?