AudioSystem.java 文件源码

/**
 * Obtains the audio file format of the provided input stream.  The stream must
 * point to valid audio file data.  The implementation of this method may require
 * multiple parsers to examine the stream to determine whether they support it.
 * These parsers must be able to mark the stream, read enough data to determine whether they
 * support the stream, and, if not, reset the stream's read pointer to its original
 * position.  If the input stream does not support these operations, this method may fail
 * with an <code>IOException</code>.
 * @param stream the input stream from which file format information should be
 * extracted
 * @return an <code>AudioFileFormat</code> object describing the stream's audio file format
 * @throws UnsupportedAudioFileException if the stream does not point to valid audio
 * file data recognized by the system
 * @throws IOException if an input/output exception occurs
 * @see InputStream#markSupported
 * @see InputStream#mark
 */
public static AudioFileFormat getAudioFileFormat(InputStream stream)
    throws UnsupportedAudioFileException, IOException {

    List providers = getAudioFileReaders();
    AudioFileFormat format = null;

    for(int i = 0; i < providers.size(); i++ ) {
        AudioFileReader reader = (AudioFileReader) providers.get(i);
        try {
            format = reader.getAudioFileFormat( stream ); // throws IOException
            break;
        } catch (UnsupportedAudioFileException e) {
            continue;
        }
    }

    if( format==null ) {
        throw new UnsupportedAudioFileException("file is not a supported file type");
    } else {
        return format;
    }
}