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/Receiver.java

/*
 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package javax.sound.midi;


/**
 * A <code>Receiver</code> receives <code>{@link MidiEvent}</code> objects and
 * typically does something useful in response, such as interpreting them to
 * generate sound or raw MIDI output.  Common MIDI receivers include
 * synthesizers and MIDI Out ports.
 *
 * @see MidiDevice
 * @see Synthesizer
 * @see Transmitter
 *
 * @author Kara Kytle
 */
public interface Receiver extends AutoCloseable {


    //$$fb 2002-04-12: fix for 4662090: Contradiction in Receiver specification
    /**
     * Sends a MIDI message and time-stamp to this receiver.
     * If time-stamping is not supported by this receiver, the time-stamp
     * value should be -1.
     * @param message the MIDI message to send
     * @param timeStamp the time-stamp for the message, in microseconds.
     * @throws IllegalStateException if the receiver is closed
     */
    public void send(MidiMessage message, long timeStamp);

    /**
     * Indicates that the application has finished using the receiver, and
     * that limited resources it requires may be released or made available.
     *
     * <p>If the creation of this <code>Receiver</code> resulted in
     * implicitly opening the underlying device, the device is
     * implicitly closed by this method. This is true unless the device is
     * kept open by other <code>Receiver</code> or <code>Transmitter</code>
     * instances that opened the device implicitly, and unless the device
     * has been opened explicitly. If the device this
     * <code>Receiver</code> is retrieved from is closed explicitly by
     * calling {@link MidiDevice#close MidiDevice.close}, the
     * <code>Receiver</code> is closed, too.  For a detailed
     * description of open/close behaviour see the class description
     * of {@link javax.sound.midi.MidiDevice MidiDevice}.
     *
     * @see javax.sound.midi.MidiSystem#getReceiver
     */
    public void close();
}

⏎ javax/sound/midi/Receiver.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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