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/CustomMarshal.java

/*
 * Copyright (c) 1999, 2003, 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;

import org.omg.CORBA.DataOutputStream;
import org.omg.CORBA.DataInputStream;

/**
 * An abstract value type that is meant to
 * be used by the ORB, not the user. Semantically it is treated
 * as a custom value type's implicit base class, although the custom
 * valuetype does not actually inherit it in IDL. The implementer
 * of a custom value type shall provide an implementation of the
 * <tt>CustomMarshal</tt> operations. The manner in which this is done is
 * specified in the IDL to Java langauge mapping. Each custom
 * marshaled value type shall have its own implementation.
 * @see DataInputStream
 */
public interface CustomMarshal {
    /**
     * Marshal method has to be implemented by the Customized Marshal class.
     * This is the method invoked for Marshalling.
     *
     * @param os a DataOutputStream
     */
    void marshal(DataOutputStream os);
    /**
     * Unmarshal method has to be implemented by the Customized Marshal class.
     * This is the method invoked for Unmarshalling.
     *
     * @param is a DataInputStream
     */
    void unmarshal(DataInputStream is);
}

⏎ org/omg/CORBA/CustomMarshal.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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