Package com.drew.imaging

Class FileTypeDetector

java.lang.Object

com.drew.imaging.FileTypeDetector

public class FileTypeDetector
extends Object

Examines the a file's first bytes and estimates the file's type.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	_bytesNeeded
private static final TypeChecker[]	_fixedCheckers
private static final ByteTrie<FileType>	_root

Constructor Summary

Constructors

Modifier	Constructor	Description
private	FileTypeDetector()

Method Summary

Modifier and Type	Method	Description
static FileType	detectFileType(InputStream inputStream)	Examines the file's bytes and estimates the file's type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

_root

private static final ByteTrie<FileType> _root

_fixedCheckers

private static final TypeChecker[] _fixedCheckers

_bytesNeeded

private static final int _bytesNeeded

Constructor Details

FileTypeDetector

private FileTypeDetector()
                  throws Exception

Throws:

Exception

Method Details

detectFileType

public static FileType detectFileType(InputStream inputStream)
                               throws IOException

Examines the file's bytes and estimates the file's type.

The input stream must support mark and reset, in order to return the stream to the position at which it was provided to this method once completed.

Requires the stream to contain at least eight bytes.

Throws:

IOException - if the stream does not support mark/reset.