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/iiop/JavaSerializationComponent.java

/*
 * Copyright (c) 2004, 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.iiop;

import org.omg.CORBA_2_3.portable.OutputStream;

import com.sun.corba.se.impl.orbutil.ORBConstants;
import com.sun.corba.se.impl.orbutil.ORBUtility;
import com.sun.corba.se.impl.protocol.giopmsgheaders.Message;

import com.sun.corba.se.spi.orb.ORB;
import com.sun.corba.se.spi.ior.TaggedComponentBase;

/**
 * Tagged component that contains a value that indicates the Java
 * serialization version supported by the ORB.
 *
 * ORB Java serialization uses IIOP as the transport protocol, but uses
 * Java serialization mechanism and its accompanying encodings, instead
 * of IIOP CDR serialization mechanism. Java serialization is generally
 * observed to be faster than CDR.
 */
public class JavaSerializationComponent extends TaggedComponentBase {

    private byte version;

    private static JavaSerializationComponent singleton;

    public static JavaSerializationComponent singleton() {
        if (singleton == null) {
            synchronized (JavaSerializationComponent.class) {
                singleton =
                    new JavaSerializationComponent(Message.JAVA_ENC_VERSION);
            }
        }
        return singleton;
    }

    public JavaSerializationComponent(byte version) {
        this.version = version;
    }

    public byte javaSerializationVersion() {
        return this.version;
    }

    public void writeContents(OutputStream os) {
        os.write_octet(version);
    }

    public int getId() {
        return ORBConstants.TAG_JAVA_SERIALIZATION_ID;
    }

    public boolean equals(Object obj) {
        if (!(obj instanceof JavaSerializationComponent)) {
            return false;
        }
        JavaSerializationComponent other = (JavaSerializationComponent) obj;
        return this.version == other.version;
    }

    public int hashCode() {
        return this.version;
    }
}

⏎ com/sun/corba/se/impl/ior/iiop/JavaSerializationComponent.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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