AudioSystem.java 文件源码

/**
 * Obtains an audio input stream from 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 operation, this method may fail
 * with an <code>IOException</code>.
 * @param stream the input stream from which the <code>AudioInputStream</code> should be
 * constructed
 * @return an <code>AudioInputStream</code> object based on the audio file data contained
 * in the input stream.
 * @throws UnsupportedAudioFileException if the stream does not point to valid audio
 * file data recognized by the system
 * @throws IOException if an I/O exception occurs
 * @see InputStream#markSupported
 * @see InputStream#mark
 */
public static AudioInputStream getAudioInputStream(InputStream stream)
    throws UnsupportedAudioFileException, IOException {

    List providers = getAudioFileReaders();
    AudioInputStream audioStream = null;

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

    if( audioStream==null ) {
        throw new UnsupportedAudioFileException("could not get audio input stream from input stream");
    } else {
        return audioStream;
    }
}