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/imageio/plugins/jpeg/JPEGMetadataFormatResources.java

/*
 * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package com.sun.imageio.plugins.jpeg;

import java.util.ListResourceBundle;

abstract class JPEGMetadataFormatResources
        extends ListResourceBundle {

    static final Object[][] commonContents = {
        // Node name, followed by description
        { "dqt", "A Define Quantization Table(s) marker segment" },
        { "dqtable", "A single quantization table" },
        { "dht", "A Define Huffman Table(s) marker segment" },
        { "dhtable", "A single Huffman table" },
        { "dri", "A Define Restart Interval marker segment" },
        { "com", "A Comment marker segment.  The user object contains "
          + "the actual bytes."},
        { "unknown", "An unrecognized marker segment.  The user object "
          + "contains the data not including length." },

        // Node name + "/" + AttributeName, followed by description
        { "dqtable/elementPrecision",
          "The number of bits in each table element (0 = 8, 1 = 16)" },
        { "dgtable/qtableId",
          "The table id" },
        { "dhtable/class",
          "Indicates whether this is a DC (0) or an AC (1) table" },
        { "dhtable/htableId",
          "The table id" },
        { "dri/interval",
          "The restart interval in MCUs" },
        { "com/comment",
          "The comment as a string (used only if user object is null)" },
        { "unknown/MarkerTag",
          "The tag identifying this marker segment" }
    };
}

⏎ com/sun/imageio/plugins/jpeg/JPEGMetadataFormatResources.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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