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/spi/RAFImageInputStreamSpi.java

/*
 * Copyright (c) 2000, 2010, 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.spi;

import java.io.File;
import java.io.RandomAccessFile;
import java.util.Locale;
import javax.imageio.spi.ImageInputStreamSpi;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.FileImageInputStream;

public class RAFImageInputStreamSpi extends ImageInputStreamSpi {

    private static final String vendorName = "Oracle Corporation";

    private static final String version = "1.0";

    private static final Class inputClass = RandomAccessFile.class;

    public RAFImageInputStreamSpi() {
        super(vendorName, version, inputClass);
    }

    public String getDescription(Locale locale) {
        return "Service provider that instantiates a FileImageInputStream from a RandomAccessFile";
    }

    public ImageInputStream createInputStreamInstance(Object input,
                                                      boolean useCache,
                                                      File cacheDir) {
        if (input instanceof RandomAccessFile) {
            try {
                return new FileImageInputStream((RandomAccessFile)input);
            } catch (Exception e) {
                return null;
            }
        } else {
            throw new IllegalArgumentException
                ("input not a RandomAccessFile!");
        }
    }
}

⏎ com/sun/imageio/spi/RAFImageInputStreamSpi.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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