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/swing/plaf/motif/MotifScrollPaneUI.java

/*
 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
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 *
 *
 *
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 *
 *
 *
 *
 *
 *
 *
 */

package com.sun.java.swing.plaf.motif;

import javax.swing.*;
import javax.swing.border.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.BasicScrollPaneUI;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

/**
 * A CDE/Motif L&F implementation of ScrollPaneUI.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases.  The current serialization support is appropriate
 * for short term storage or RMI between applications running the same
 * version of Swing.  A future release of Swing will provide support for
 * long term persistence.
 *
 * @author Hans Muller
 */
public class MotifScrollPaneUI extends BasicScrollPaneUI
{
    private final static Border vsbMarginBorderR = new EmptyBorder(0, 4, 0, 0);
    private final static Border vsbMarginBorderL = new EmptyBorder(0, 0, 0, 4);
    private final static Border hsbMarginBorder = new EmptyBorder(4, 0, 0, 0);

    private CompoundBorder vsbBorder;
    private CompoundBorder hsbBorder;

    private PropertyChangeListener propertyChangeHandler;

    @Override
    protected void installListeners(JScrollPane scrollPane) {
        super.installListeners(scrollPane);
        propertyChangeHandler = createPropertyChangeHandler();
        scrollPane.addPropertyChangeListener(propertyChangeHandler);
    }

    @Override
    protected void uninstallListeners(JComponent scrollPane) {
        super.uninstallListeners(scrollPane);
        scrollPane.removePropertyChangeListener(propertyChangeHandler);
    }

    private PropertyChangeListener createPropertyChangeHandler() {
        return new PropertyChangeListener() {
            @Override
            public void propertyChange(PropertyChangeEvent e) {
                  String propertyName = e.getPropertyName();

                  if (propertyName.equals("componentOrientation")) {
                        JScrollPane pane = (JScrollPane)e.getSource();
                        JScrollBar vsb = pane.getVerticalScrollBar();
                        if (vsb != null && vsbBorder != null &&
                            vsb.getBorder() == vsbBorder) {
                            // The Border on the verticall scrollbar matches
                            // what we installed, reset it.
                            if (MotifGraphicsUtils.isLeftToRight(pane)) {
                                vsbBorder = new CompoundBorder(vsbMarginBorderR,
                                                vsbBorder.getInsideBorder());
                            } else {
                                vsbBorder = new CompoundBorder(vsbMarginBorderL,
                                                vsbBorder.getInsideBorder());
                            }
                            vsb.setBorder(vsbBorder);
                        }
                  }
        }};
    }

    @Override
    protected void installDefaults(JScrollPane scrollpane) {
        super.installDefaults(scrollpane);

        JScrollBar vsb = scrollpane.getVerticalScrollBar();
        if (vsb != null) {
            if (MotifGraphicsUtils.isLeftToRight(scrollpane)) {
                vsbBorder = new CompoundBorder(vsbMarginBorderR,
                                               vsb.getBorder());
            }
            else {
                vsbBorder = new CompoundBorder(vsbMarginBorderL,
                                               vsb.getBorder());
            }
            vsb.setBorder(vsbBorder);
        }

        JScrollBar hsb = scrollpane.getHorizontalScrollBar();
        if (hsb != null) {
            hsbBorder = new CompoundBorder(hsbMarginBorder, hsb.getBorder());
            hsb.setBorder(hsbBorder);
        }
    }

    @Override
    protected void uninstallDefaults(JScrollPane c) {
        super.uninstallDefaults(c);

        JScrollBar vsb = scrollpane.getVerticalScrollBar();
        if (vsb != null) {
            if (vsb.getBorder() == vsbBorder) {
                vsb.setBorder(null);
            }
            vsbBorder = null;
        }

        JScrollBar hsb = scrollpane.getHorizontalScrollBar();
        if (hsb != null) {
            if (hsb.getBorder() == hsbBorder) {
                hsb.setBorder(null);
            }
            hsbBorder = null;
        }
    }


    public static ComponentUI createUI(JComponent x) {
        return new MotifScrollPaneUI();
    }
}

⏎ com/sun/java/swing/plaf/motif/MotifScrollPaneUI.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
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