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/FREE_MEM.java

/*
 * Copyright (c) 1995, 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;

/**
 * Exception thrown
 * when the ORB failed in an attempt to free dynamic memory, for example
 * because of heap corruption or memory segments being locked.<P>
 * It contains a minor code, which gives more detailed information about
 * what caused the exception, and a completion status. It may also contain
 * a string describing the exception.
 *
 * @see <A href="../../../../technotes/guides/idl/jidlExceptions.html">documentation on
 * Java&nbsp;IDL exceptions</A>
 * @since       JDK1.2
 */

public final class FREE_MEM extends SystemException {
    /**
     * Constructs a <code>FREE_MEM</code> exception with a default
     * minor code of 0 and a completion state of COMPLETED_NO.
     */
    public FREE_MEM() {
        this("");
    }

    /**
     * Constructs a <code>FREE_MEM</code> exception with the specified detail
     * message, a minor code of 0, and a completion state of COMPLETED_NO.
     *
     * @param s the String containing a detail message
     */
    public FREE_MEM(String s) {
        this(s, 0, CompletionStatus.COMPLETED_NO);
    }

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

    /**
     * Constructs a <code>FREE_MEM</code> exception with the specified detail
     * message, minor code, and completion status.
     * A detail message is a String that describes this particular exception.
     * @param s the String containing a detail message
     * @param minor the minor code
     * @param completed the completion status
     */
    public FREE_MEM(String s, int minor, CompletionStatus completed) {
        super(s, minor, completed);
    }
}

⏎ org/omg/CORBA/FREE_MEM.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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