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/stream/CloseableDisposerRecord.java

/*
 * Copyright (c) 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.imageio.stream;

import java.io.Closeable;
import java.io.IOException;
import sun.java2d.DisposerRecord;

/**
 * Convenience class that closes a given resource (e.g. RandomAccessFile),
 * typically associated with an Image{Input,Output}Stream, prior to the
 * stream being garbage collected.
 */
public class CloseableDisposerRecord implements DisposerRecord {
    private Closeable closeable;

    public CloseableDisposerRecord(Closeable closeable) {
        this.closeable = closeable;
    }

    public synchronized void dispose() {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (IOException e) {
            } finally {
                closeable = null;
            }
        }
    }
}

⏎ com/sun/imageio/stream/CloseableDisposerRecord.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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