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/java_cup/internal/runtime/Scanner.java

/*
 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package com.sun.java_cup.internal.runtime;

/**
 * Defines the Scanner interface, which CUP uses in the default
 * implementation of <code>lr_parser.scan()</code>.  Integration
 * of scanners implementing <code>Scanner</code> is facilitated.
 *
 * @author David MacMahon <davidm@smartsc.com>
 */

/* *************************************************
  Interface Scanner

  Declares the next_token() method that should be
  implemented by scanners.  This method is typically
  called by lr_parser.scan().
 ***************************************************/
public interface Scanner {
    public Symbol next_token() throws java.lang.Exception;
}

⏎ com/sun/java_cup/internal/runtime/Scanner.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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