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/stub/java/rmi/_Remote_Stub.java

/*
 * Copyright (c) 1999, 2000, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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/*
 * Licensed Materials - Property of IBM
 * RMI-IIOP v1.0
 * Copyright IBM Corp. 1998 1999  All Rights Reserved
 *
 */

// Stub class generated by rmic, do not edit.
// Contents subject to change without notice.

package org.omg.stub.java.rmi;

import java.rmi.Remote;
import javax.rmi.CORBA.Stub;

/**
 * This class provides the Stub for the Remote Type.  The class is generated
 * by the rmic compiler, and is still under works at OMG.  It's contents are
 * subject to change without notice as the specification evolves.
 */
public final class _Remote_Stub extends Stub implements Remote {

    private static final String _type_ids[] = {
        ""
    };

    /**
     * Returns an array of repository ids that an object implements.
     * The string at index zero represents the most derived interface.  The last id,
     * for the generic CORBA object is (i.e., IDL:omg.org/CORBA/Object:1.0") is
     * implied and not present.
     * @return an array of repository ids that an object implements.
     */
    public String[] _ids() {
        return (String[]) _type_ids.clone();
    }
}

⏎ org/omg/stub/java/rmi/_Remote_Stub.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

⇑ Download and Use JDK 8

⇑⇑ FAQ for JDK (Java Development Kit)