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 org.* package in JRE 1.8.0_191 rt.jar. Java source codes are also provided.

⏎ org/omg/CORBA/ACTIVITY_REQUIRED.java

/*
 * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package org.omg.CORBA;

/**
 * The <code>ACTIVITY_REQUIRED</code> system exception may be raised on any
 * method for which an Activity context is required. It indicates that an
 * Activity context was necessary to perform the invoked operation, but one
 * was not found associated with the calling thread.
 *
 * @see <A href="../../../../technotes/guides/idl/jidlExceptions.html">documentation on
 *      Java&nbsp;IDL exceptions</A>
 * @since   J2SE 1.5
 */

public final class ACTIVITY_REQUIRED extends SystemException {

    /**
     * Constructs an <code>ACTIVITY_REQUIRED</code> exception with
     * minor code set to 0 and CompletionStatus set to COMPLETED_NO.
     */
    public ACTIVITY_REQUIRED() {
        this("");
    }

    /**
     * Constructs an <code>ACTIVITY_REQUIRED</code> exception with the
     * specified message.
     *
     * @param detailMessage string containing a detailed message.
     */
    public ACTIVITY_REQUIRED(String detailMessage) {
        this(detailMessage, 0, CompletionStatus.COMPLETED_NO);
    }

    /**
     * Constructs an <code>ACTIVITY_REQUIRED</code> exception with the
     * specified minor code and completion status.
     *
     * @param minorCode minor code.
     * @param completionStatus completion status.
     */
    public ACTIVITY_REQUIRED(int minorCode,
                             CompletionStatus completionStatus) {
        this("", minorCode, completionStatus);
    }

    /**
     * Constructs an <code>ACTIVITY_REQUIRED</code> exception with the
     * specified message, minor code, and completion status.
     *
     * @param detailMessage string containing a detailed message.
     * @param minorCode minor code.
     * @param completionStatus completion status.
     */
    public ACTIVITY_REQUIRED(String detailMessage,
                             int minorCode,
                             CompletionStatus completionStatus) {
        super(detailMessage, minorCode, completionStatus);
    }
}

⏎ org/omg/CORBA/ACTIVITY_REQUIRED.java

Or download all of them as a single archive file:

File name: jre-rt-org-1.8.0_191-src.zip
File size: 951125 bytes
Release date: 2018-10-28
Download 

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

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

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