JRE 8 rt.jar is the JAR file for JRE 8 RT (Runtime) libraries. JRE (Java Runtime) 8 is the runtime environment included in JDK 8. JRE 8 rt.jar libraries are divided into 6 packages:

com.* - Internal Oracle and Sun Microsystems libraries
java.* - Standard Java API libraries.
javax.* - Extended Java API libraries.
jdk.* -  JDK supporting libraries.
org.* - Third party libraries.
sun.* - Old libraries developed by Sun Microsystems.

JAR File Information:

Directory of C:\fyicenter\jdk-1.8.0_191\jre\lib
      63,596,151 rt.jar

Here is the list of Java classes of the javax.* package in JRE 1.8.0_191 rt.jar. Java source codes are also provided.

⏎ javax/sound/midi/spi/MidiFileReader.java

/*
 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 *
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 */

package javax.sound.midi.spi;

import java.io.File;
import java.io.InputStream;
import java.io.IOException;
import java.net.URL;

import javax.sound.midi.MidiFileFormat;
import javax.sound.midi.Sequence;
import javax.sound.midi.InvalidMidiDataException;

/**
 * A {@code MidiFileReader} supplies MIDI file-reading services. Classes
 * implementing this interface can parse the format information from one or more
 * types of MIDI file, and can produce a {@link Sequence} object from files of
 * these types.
 *
 * @author Kara Kytle
 * @since 1.3
 */
public abstract class MidiFileReader {

    /**
     * Obtains the MIDI file format of the input stream provided. The stream
     * must point to valid MIDI file data. In general, MIDI file readers may
     * need to read some data from the stream before determining 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 this, this method may fail with an {@code IOException}.
     *
     * @param  stream the input stream from which file format information
     *         should be extracted
     * @return a {@code MidiFileFormat} object describing the MIDI file format
     * @throws InvalidMidiDataException if the stream does not point to valid
     *         MIDI file data recognized by the system
     * @throws IOException if an I/O exception occurs
     * @see InputStream#markSupported
     * @see InputStream#mark
     */
    public abstract MidiFileFormat getMidiFileFormat(InputStream stream)
            throws InvalidMidiDataException, IOException;

    /**
     * Obtains the MIDI file format of the URL provided. The URL must point to
     * valid MIDI file data.
     *
     * @param  url the URL from which file format information should be
     *         extracted
     * @return a {@code MidiFileFormat} object describing the MIDI file format
     * @throws InvalidMidiDataException if the URL does not point to valid MIDI
     *         file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public abstract MidiFileFormat getMidiFileFormat(URL url)
            throws InvalidMidiDataException, IOException;

    /**
     * Obtains the MIDI file format of the {@code File} provided. The
     * {@code File} must point to valid MIDI file data.
     *
     * @param  file the {@code File} from which file format information should
     *         be extracted
     * @return a {@code MidiFileFormat} object describing the MIDI file format
     * @throws InvalidMidiDataException if the {@code File} does not point to
     *         valid MIDI file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public abstract MidiFileFormat getMidiFileFormat(File file)
            throws InvalidMidiDataException, IOException;

    /**
     * Obtains a MIDI sequence from the input stream provided. The stream must
     * point to valid MIDI file data. In general, MIDI file readers may need to
     * read some data from the stream before determining 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 this, this method may fail with an IOException.
     *
     * @param  stream the input stream from which the {@code Sequence} should
     *         be constructed
     * @return a {@code Sequence} object based on the MIDI file data contained
     *         in the input stream.
     * @throws InvalidMidiDataException if the stream does not point to valid
     *         MIDI file data recognized by the system
     * @throws IOException if an I/O exception occurs
     * @see InputStream#markSupported
     * @see InputStream#mark
     */
    public abstract Sequence getSequence(InputStream stream)
            throws InvalidMidiDataException, IOException;

    /**
     * Obtains a MIDI sequence from the URL provided. The URL must point to
     * valid MIDI file data.
     *
     * @param  url the URL for which the {@code Sequence} should be constructed
     * @return a {@code Sequence} object based on the MIDI file data pointed to
     *         by the URL
     * @throws InvalidMidiDataException if the URL does not point to valid MIDI
     *         file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public abstract Sequence getSequence(URL url)
            throws InvalidMidiDataException, IOException;

    /**
     * Obtains a MIDI sequence from the {@code File} provided. The {@code File}
     * must point to valid MIDI file data.
     *
     * @param  file the {@code File} from which the {@code Sequence} should be
     *         constructed
     * @return a {@code Sequence} object based on the MIDI file data pointed to
     *         by the {@code File}
     * @throws InvalidMidiDataException if the {@code File} does not point to
     *         valid MIDI file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public abstract Sequence getSequence(File file)
            throws InvalidMidiDataException, IOException;
}

⏎ javax/sound/midi/spi/MidiFileReader.java

Or download all of them as a single archive file:

File name: jre-rt-javax-1.8.0_191-src.zip
File size: 5381005 bytes
Release date: 2018-10-28
Download 

⇒ JRE 8 rt.jar - org.* Package Source Code

⇐ JRE 8 rt.jar - java.* Package Source Code

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