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/OldPOAObjectKeyTemplate.java

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

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

import org.omg.CORBA.INTERNAL ;
import org.omg.CORBA.OctetSeqHolder ;

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

import com.sun.corba.se.spi.orb.ORB ;
import com.sun.corba.se.spi.orb.ORBVersion ;
import com.sun.corba.se.spi.orb.ORBVersionFactory ;

import com.sun.corba.se.impl.ior.ObjectKeyFactoryImpl ;

/**
 * @author Ken Cavanaugh
 */
public final class OldPOAObjectKeyTemplate extends OldObjectKeyTemplateBase
{
    /** This constructor reads the template ONLY from the stream
    */
    public OldPOAObjectKeyTemplate( ORB orb, int magic, int scid, InputStream is )
    {
        this( orb, magic, scid, is.read_long(), is.read_long(), is.read_long() ) ;
    }

    /** This constructor reads a complete ObjectKey (template and Id)
    * from the stream.
    */
    public OldPOAObjectKeyTemplate( ORB orb, int magic, int scid, InputStream is,
        OctetSeqHolder osh )
    {
        this( orb, magic, scid, is ) ;
        osh.value = readObjectKey( is ) ;
    }

    public OldPOAObjectKeyTemplate( ORB orb, int magic, int scid, int serverid,
        int orbid, int poaid)
    {
        super( orb, magic, scid, serverid,
            Integer.toString( orbid ),
            new ObjectAdapterIdNumber( poaid ) ) ;
    }

    public void writeTemplate(OutputStream os)
    {
        os.write_long( getMagic() ) ;
        os.write_long( getSubcontractId() ) ;
        os.write_long( getServerId() ) ;

        int orbid = Integer.parseInt( getORBId() ) ;
        os.write_long( orbid ) ;

        ObjectAdapterIdNumber oaid = (ObjectAdapterIdNumber)(getObjectAdapterId()) ;
        int poaid = oaid.getOldPOAId()  ;
        os.write_long( poaid ) ;
    }

    public ORBVersion getORBVersion()
    {
        if (getMagic() == ObjectKeyFactoryImpl.JAVAMAGIC_OLD)
            return ORBVersionFactory.getOLD() ;
        else if (getMagic() == ObjectKeyFactoryImpl.JAVAMAGIC_NEW)
            return ORBVersionFactory.getNEW() ;
        else
            throw new INTERNAL() ;
    }
}

⏎ com/sun/corba/se/impl/ior/OldPOAObjectKeyTemplate.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 

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