org.apache.tika.detect
Class MagicDetector

java.lang.Object
  extended by org.apache.tika.detect.MagicDetector
All Implemented Interfaces:
Serializable, Detector

public class MagicDetector
extends Object
implements Detector

Content type detection based on magic bytes, i.e. type-specific patterns near the beginning of the document input stream.

Since:
Apache Tika 0.3
See Also:
Serialized Form

Constructor Summary
MagicDetector(MediaType type, byte[] pattern)
          Creates a detector for input documents that have the exact given byte pattern at the beginning of the document stream.
MagicDetector(MediaType type, byte[] pattern, byte[] mask, int offsetRangeBegin, int offsetRangeEnd)
          Creates a detector for input documents that meet the specified magic match.
MagicDetector(MediaType type, byte[] pattern, int offset)
          Creates a detector for input documents that have the exact given byte pattern at the given offset of the document stream.
 
Method Summary
 MediaType detect(InputStream input, Metadata metadata)
          Detects the content type of the given input document.
 String toString()
          Returns a string representation of the Detection Rule.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

MagicDetector

public MagicDetector(MediaType type,
                     byte[] pattern)
Creates a detector for input documents that have the exact given byte pattern at the beginning of the document stream.

Parameters:
type - matching media type
pattern - magic match pattern

MagicDetector

public MagicDetector(MediaType type,
                     byte[] pattern,
                     int offset)
Creates a detector for input documents that have the exact given byte pattern at the given offset of the document stream.

Parameters:
type - matching media type
pattern - magic match pattern
offset - offset of the pattern match

MagicDetector

public MagicDetector(MediaType type,
                     byte[] pattern,
                     byte[] mask,
                     int offsetRangeBegin,
                     int offsetRangeEnd)
Creates a detector for input documents that meet the specified magic match.

Method Detail

detect

public MediaType detect(InputStream input,
                        Metadata metadata)
                 throws IOException
Description copied from interface: Detector
Detects the content type of the given input document. Returns application/octet-stream if the type of the document can not be detected.

If the document input stream is not available, then the first argument may be null. Otherwise the detector may read bytes from the start of the stream to help in type detection. The given stream is guaranteed to support the mark feature and the detector is expected to mark the stream before reading any bytes from it, and to reset the stream before returning. The stream must not be closed by the detector.

The given input metadata is only read, not modified, by the detector.

Specified by:
detect in interface Detector
Parameters:
input - document input stream, or null
metadata - ignored
Returns:
detected media type, or application/octet-stream
Throws:
IOException - if the document input stream could not be read

toString

public String toString()
Returns a string representation of the Detection Rule. Should sort nicely by type and details, as we sometimes compare these.

Overrides:
toString in class Object


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