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/transport/ReadTCPTimeoutsImpl.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.transport;

import com.sun.corba.se.spi.transport.ReadTimeouts;

/**
 * @author Charlie Hunt
 */
public class ReadTCPTimeoutsImpl implements ReadTimeouts
{
    private int initial_time_to_wait;
    private int max_time_to_wait;
    private int max_giop_header_time_to_wait;
    private double backoff_factor;

    // constructor
    public ReadTCPTimeoutsImpl(int initial_time,
                            int max_time,
                            int max_giop_header_time,
                            int backoff_percent) {
        this.initial_time_to_wait = initial_time;
        this.max_time_to_wait = max_time;
        this.max_giop_header_time_to_wait = max_giop_header_time;
        this.backoff_factor = 1 + (double)(backoff_percent)/100;
    }

    public int get_initial_time_to_wait() { return initial_time_to_wait; }
    public int get_max_time_to_wait() { return max_time_to_wait; }
    public double get_backoff_factor() { return backoff_factor; }
    public int get_max_giop_header_time_to_wait() {
        return max_giop_header_time_to_wait; }
}

// End of file.

⏎ com/sun/corba/se/impl/transport/ReadTCPTimeoutsImpl.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)