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/management/monitor/MonitorMBean.java

/*
 * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package javax.management.monitor;

// jmx imports
//
import javax.management.ObjectName;

/**
 * Exposes the remote management interface of monitor MBeans.
 *
 *
 * @since 1.5
 */
public interface MonitorMBean {

    /**
     * Starts the monitor.
     */
    public void start();

    /**
     * Stops the monitor.
     */
    public void stop();

    // GETTERS AND SETTERS
    //--------------------

    /**
     * Adds the specified object in the set of observed MBeans.
     *
     * @param object The object to observe.
     * @exception java.lang.IllegalArgumentException the specified object is null.
     *
     */
    public void addObservedObject(ObjectName object) throws java.lang.IllegalArgumentException;

    /**
     * Removes the specified object from the set of observed MBeans.
     *
     * @param object The object to remove.
     *
     */
    public void removeObservedObject(ObjectName object);

    /**
     * Tests whether the specified object is in the set of observed MBeans.
     *
     * @param object The object to check.
     * @return <CODE>true</CODE> if the specified object is in the set, <CODE>false</CODE> otherwise.
     *
     */
    public boolean containsObservedObject(ObjectName object);

    /**
     * Returns an array containing the objects being observed.
     *
     * @return The objects being observed.
     *
     */
    public ObjectName[] getObservedObjects();

    /**
     * Gets the object name of the object being observed.
     *
     * @return The object being observed.
     *
     * @see #setObservedObject
     *
     * @deprecated As of JMX 1.2, replaced by {@link #getObservedObjects}
     */
    @Deprecated
    public ObjectName getObservedObject();

    /**
     * Sets the object to observe identified by its object name.
     *
     * @param object The object to observe.
     *
     * @see #getObservedObject
     *
     * @deprecated As of JMX 1.2, replaced by {@link #addObservedObject}
     */
    @Deprecated
    public void setObservedObject(ObjectName object);

    /**
     * Gets the attribute being observed.
     *
     * @return The attribute being observed.
     *
     * @see #setObservedAttribute
     */
    public String getObservedAttribute();

    /**
     * Sets the attribute to observe.
     *
     * @param attribute The attribute to observe.
     *
     * @see #getObservedAttribute
     */
    public void setObservedAttribute(String attribute);

    /**
     * Gets the granularity period (in milliseconds).
     *
     * @return The granularity period.
     *
     * @see #setGranularityPeriod
     */
    public long getGranularityPeriod();

    /**
     * Sets the granularity period (in milliseconds).
     *
     * @param period The granularity period.
     * @exception java.lang.IllegalArgumentException The granularity
     * period is less than or equal to zero.
     *
     * @see #getGranularityPeriod
     */
    public void setGranularityPeriod(long period) throws java.lang.IllegalArgumentException;

    /**
     * Tests if the monitor MBean is active.
     * A monitor MBean is marked active when the {@link #start start} method is called.
     * It becomes inactive when the {@link #stop stop} method is called.
     *
     * @return <CODE>true</CODE> if the monitor MBean is active, <CODE>false</CODE> otherwise.
     */
    public boolean isActive();
}

⏎ javax/management/monitor/MonitorMBean.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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