[TIKA-3833] bzip2 MIME type is detected as bzip instead when using tika-core

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.1
• Fix Version/s: 2.5.0
• Component/s: core

Language

scala

• Assignee: Unassigned
• Reporter: Eduardas Kazakas
• Created: 08/Aug/22 17:57
• Updated: 14/Sep/22 18:26
• Resolved: 10/Aug/22 17:16

Description

Hello, I'm having a bit of a problem when using the tika-core module (v2.4.1).
I am trying to detect the MIME type of a bzip2 file and, instead of
application/x-bzip2, I am getting application/x-bzip. I believe it has
something to do with the mime-type definitions in the
tika-mimetypes.xml file.

<mime-type type="application/x-bzip">
  <magic priority="40">
    <match value="BZh" type="string" offset="0"/>
  </magic>
  <glob pattern="*.bz"/>
  <glob pattern="*.tbz"/>
</mime-type>
<mime-type type="application/x-bzip2">
  <sub-class-of type="application/x-bzip"/>
  <_comment>Bzip 2 UNIX Compressed File</_comment>
  <magic priority="40">
    <match value="\x42\x5a\x68\x39\x31" type="string" offset="0"/>
  </magic>
  <glob pattern="*.bz2"/>
  <glob pattern="*.tbz2"/>
  <glob pattern="*.boz"/>
</mime-type>

The priority for these is set to 40, I believe that the priority of
application/x-bzip2 should be higher, because string value "BZh" and
hex value part "\x42\x5a\x68" are equal. x42\x5a\x68 = BZh.

Maybe I am missing something here? Does this look like a bug or this
works as intended? Maybe I can provide some sort of hint for the
default detector?

A small example in Scala:

import org.apache.tika.config.TikaConfig
import org.apache.tika.detect.DefaultProbDetector
import org.apache.tika.metadata.{Metadata, TikaCoreProperties}

import java.io.{BufferedInputStream, File, FileInputStream}

object AAA {
  def main(args: Array[String]): Unit = {
    val config = TikaConfig.getDefaultConfig

    val file = new File("/home/ekazakas/test.csv.bz2")
    val detector = new DefaultProbDetector()
    val mediaType = detector.detect(new BufferedInputStream(new FileInputStream(file)), new Metadata)
    val mimeType = config.getMimeRepository.forName(mediaType.toString)
    println(mimeType)
  }
} 

This prints `application/x-bzip` instead of `application/x-bzip2`.