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/orbutil/GetPropertyAction.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.orbutil ;

/**
 * A convenience class for retrieving the string value of a system
 * property as a privileged action.  This class is directly copied
 * from sun.security.action.GetPropertyAction in order to avoid
 * depending on the sun.security.action package.
 *
 * <p>An instance of this class can be used as the argument of
 * <code>AccessController.doPrivileged</code>.
 *
 * <p>The following code retrieves the value of the system
 * property named <code>"prop"</code> as a privileged action: <p>
 *
 * <pre>
 * String s = (String) java.security.AccessController.doPrivileged(
 *                         new GetPropertyAction("prop"));
 * </pre>
 *
 * @author Roland Schemers
 * @author Ken Cavanaugh
 * @see java.security.PrivilegedAction
 * @see java.security.AccessController
 */

public class GetPropertyAction implements java.security.PrivilegedAction {
    private String theProp;
    private String defaultVal;

    /**
     * Constructor that takes the name of the system property whose
     * string value needs to be determined.
     *
     * @param theProp the name of the system property.
     */
    public GetPropertyAction(String theProp) {
        this.theProp = theProp;
    }

    /**
     * Constructor that takes the name of the system property and the default
     * value of that property.
     *
     * @param theProp the name of the system property.
     * @param defaulVal the default value.
     */
    public GetPropertyAction(String theProp, String defaultVal) {
        this.theProp = theProp;
        this.defaultVal = defaultVal;
    }

    /**
     * Determines the string value of the system property whose
     * name was specified in the constructor.
     *
     * @return the string value of the system property,
     *         or the default value if there is no property with that key.
     */
    public Object run() {
        String value = System.getProperty(theProp);
        return (value == null) ? defaultVal : value;
    }
}

⏎ com/sun/corba/se/impl/orbutil/GetPropertyAction.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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