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

⏎ com/sun/corba/se/impl/ior/GenericIdentifiable.java

/*
 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package com.sun.corba.se.impl.ior;

import java.util.Arrays ;

import org.omg.CORBA_2_3.portable.InputStream;
import org.omg.CORBA_2_3.portable.OutputStream;

import com.sun.corba.se.spi.ior.Identifiable ;

/**
 * @author
 * This is used for unknown components and profiles.  A TAG_MULTICOMPONENT_PROFILE will be represented this way.
 */
public abstract class GenericIdentifiable implements Identifiable
{
    private int id;
    private byte data[];

    public GenericIdentifiable(int id, InputStream is)
    {
        this.id = id ;
        data = EncapsulationUtility.readOctets( is ) ;
    }

    public int getId()
    {
        return id ;
    }

    public void write(OutputStream os)
    {
        os.write_ulong( data.length ) ;
        os.write_octet_array( data, 0, data.length ) ;
    }

    public String toString()
    {
        return "GenericIdentifiable[id=" + getId() + "]" ;
    }

    public boolean equals(Object obj)
    {
        if (obj == null)
            return false ;

        if (!(obj instanceof GenericIdentifiable))
            return false ;

        GenericIdentifiable encaps = (GenericIdentifiable)obj ;

        return (getId() == encaps.getId()) &&
            Arrays.equals( getData(), encaps.getData() ) ;
    }

    public int hashCode()
    {
        int result = 17 ;
        for (int ctr=0; ctr<data.length; ctr++ )
            result = 37*result + data[ctr] ;
        return result ;
    }

    public GenericIdentifiable(int id, byte[] data)
    {
        this.id = id ;
        this.data = (byte[])(data.clone()) ;
    }

    public byte[] getData()
    {
        return data ;
    }
}

⏎ com/sun/corba/se/impl/ior/GenericIdentifiable.java

Or download all of them as a single archive file:

File name: jre-rt-com-1.8.0_191-src.zip
File size: 8099783 bytes
Release date: 2018-10-28
Download 

⇒ Backup JDK 8 Installation Directory

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

⇑ Download and Use JDK 8

⇑⇑ FAQ for JDK (Java Development Kit)