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/presentation/rmi/StubFactoryBase.java

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

package com.sun.corba.se.impl.presentation.rmi ;

import javax.rmi.CORBA.Tie ;

import java.lang.reflect.InvocationHandler ;
import java.lang.reflect.Proxy ;

import com.sun.corba.se.spi.presentation.rmi.PresentationManager ;
import com.sun.corba.se.spi.presentation.rmi.DynamicStub ;
import com.sun.corba.se.spi.presentation.rmi.StubAdapter ;

import com.sun.corba.se.spi.orbutil.proxy.InvocationHandlerFactory ;
import com.sun.corba.se.spi.orbutil.proxy.LinkedInvocationHandler ;

public abstract class StubFactoryBase implements PresentationManager.StubFactory
{
    private String[] typeIds = null ;

    protected final PresentationManager.ClassData classData ;

    protected StubFactoryBase( PresentationManager.ClassData classData )
    {
        this.classData = classData ;
    }

    public synchronized String[] getTypeIds()
    {
        if (typeIds == null) {
            if (classData == null) {
                org.omg.CORBA.Object stub = makeStub() ;
                typeIds = StubAdapter.getTypeIds( stub ) ;
            } else {
                typeIds = classData.getTypeIds() ;
            }
        }

        return typeIds ;
    }
}

⏎ com/sun/corba/se/impl/presentation/rmi/StubFactoryBase.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)