org.apache.tika.detect
Class MagicDetector

java.lang.Object
  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.
int	getLength()
static MagicDetector	parse(MediaType mediaType, String type, String offset, String value, String mask)
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

parse

public static MagicDetector parse(MediaType mediaType,
                                  String type,
                                  String offset,
                                  String value,
                                  String mask)

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

getLength

public int getLength()

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