Package jakarta.activation

Class MimetypesFileTypeMap

java.lang.Object
jakarta.activation.FileTypeMap
jakarta.activation.MimetypesFileTypeMap
public class MimetypesFileTypeMap extends FileTypeMap
This class extends FileTypeMap and provides data typing of files via their file extension. It uses the .mime.types format.

MIME types file search order:

The MimetypesFileTypeMap looks in various places in the user's system for MIME types file entries. When requests are made to search for MIME types in the MimetypesFileTypeMap, it searches MIME types files in the following order:

  1. Programmatically added entries to the MimetypesFileTypeMap instance.
  2. The file .mime.types in the user's home directory.
  3. The file mime.types in the Java runtime.
  4. The file or resources named META-INF/mime.types.
  5. The file or resource named META-INF/mimetypes.default (usually found only in the activation.jar file).

(The current implementation looks for the mime.types file in the Java runtime in the directory java.home/conf if it exists, and otherwise in the directory java.home/lib, where java.home is the value of the "java.home" System property. Note that the "conf" directory was introduced in JDK 9.)

MIME types file format:

# comments begin with a '#'
# the format is <mime type> <space separated file extensions>
# for example:
text/plain txt text TXT
# this would map file.txt, file.text, and file.TXT to
# the mime type "text/plain"

  • Constructor Details

    • MimetypesFileTypeMap

      public MimetypesFileTypeMap()
      The default constructor.

    • MimetypesFileTypeMap

      public MimetypesFileTypeMap(String mimeTypeFileName) throws IOException
      Construct a MimetypesFileTypeMap with programmatic entries added from the named file.
      Parameters:
      mimeTypeFileName - the file name
      Throws:
      IOException - for errors reading the file

    • MimetypesFileTypeMap

      public MimetypesFileTypeMap(InputStream is)
      Construct a MimetypesFileTypeMap with programmatic entries added from the InputStream.
      Parameters:
      is - the input stream to read from

  • Method Details

    • addMimeTypes

      public void addMimeTypes(String mime_types)
      Prepend the MIME type values to the registry.
      Parameters:
      mime_types - A .mime.types formatted string of entries.

    • getContentType

      public String getContentType(File f)
      Return the MIME type of the file object. The implementation in this class calls getContentType(f.getName()).
      Specified by:
      getContentType in class FileTypeMap
      Parameters:
      f - the file
      Returns:
      the file's MIME type

    • getContentType

      public String getContentType(String filename)
      Return the MIME type based on the specified file name. The MIME type entries are searched as described above under MIME types file search order. If no entry is found, the type "application/octet-stream" is returned.
      Specified by:
      getContentType in class FileTypeMap
      Parameters:
      filename - the file name
      Returns:
      the file's MIME type