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 javax.* package in JRE 1.8.0_191 rt.jar. Java source codes are also provided.

⏎ javax/swing/colorchooser/DiagramComponent.java

/*
 * Copyright (c) 2008, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.swing.colorchooser;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import javax.swing.JComponent;

final class DiagramComponent extends JComponent implements MouseListener, MouseMotionListener {

    private final ColorPanel panel;
    private final boolean diagram;

    private final Insets insets = new Insets(0, 0, 0, 0);

    private int width;
    private int height;

    private int[] array;
    private BufferedImage image;

    DiagramComponent(ColorPanel panel, boolean diagram) {
        this.panel = panel;
        this.diagram = diagram;
        addMouseListener(this);
        addMouseMotionListener(this);
    }

    @Override
    protected void paintComponent(Graphics g) {
        getInsets(this.insets);
        this.width = getWidth() - this.insets.left - this.insets.right;
        this.height = getHeight() - this.insets.top - this.insets.bottom;

        boolean update = (this.image == null)
                || (this.width != this.image.getWidth())
                || (this.height != this.image.getHeight());
        if (update) {
            int size = this.width * this.height;
            if ((this.array == null) || (this.array.length < size)) {
                this.array = new int[size];
            }
            this.image = new BufferedImage(this.width, this.height, BufferedImage.TYPE_INT_RGB);
        }
        {
            float dx = 1.0f / (float) (this.width - 1);
            float dy = 1.0f / (float) (this.height - 1);

            int offset = 0;
            float y = 0.0f;
            for (int h = 0; h < this.height; h++, y += dy) {
                if (this.diagram) {
                    float x = 0.0f;
                    for (int w = 0; w < this.width; w++, x += dx, offset++) {
                        this.array[offset] = this.panel.getColor(x, y);
                    }
                }
                else {
                    int color = this.panel.getColor(y);
                    for (int w = 0; w < this.width; w++, offset++) {
                        this.array[offset] = color;
                    }
                }
            }
        }
        this.image.setRGB(0, 0, this.width, this.height, this.array, 0, this.width);
        g.drawImage(this.image, this.insets.left, this.insets.top, this.width, this.height, this);
        if (isEnabled()) {
            this.width--;
            this.height--;
            g.setXORMode(Color.WHITE);
            g.setColor(Color.BLACK);
            if (this.diagram) {
                int x = getValue(this.panel.getValueX(), this.insets.left, this.width);
                int y = getValue(this.panel.getValueY(), this.insets.top, this.height);
                g.drawLine(x - 8, y, x + 8, y);
                g.drawLine(x, y - 8, x, y + 8);
            }
            else {
                int z = getValue(this.panel.getValueZ(), this.insets.top, this.height);
                g.drawLine(this.insets.left, z, this.insets.left + this.width, z);
            }
            g.setPaintMode();
        }
    }

    public void mousePressed(MouseEvent event) {
        mouseDragged(event);
    }

    public void mouseReleased(MouseEvent event) {
    }

    public void mouseClicked(MouseEvent event) {
    }

    public void mouseEntered(MouseEvent event) {
    }

    public void mouseExited(MouseEvent event) {
    }

    public void mouseMoved(MouseEvent event) {
    }

    public void mouseDragged(MouseEvent event) {
        if (isEnabled()) {
            float y = getValue(event.getY(), this.insets.top, this.height);
            if (this.diagram) {
                float x = getValue(event.getX(), this.insets.left, this.width);
                this.panel.setValue(x, y);
            }
            else {
                this.panel.setValue(y);
            }
        }
    }

    private static int getValue(float value, int min, int max) {
        return min + (int) (value * (float) (max));
    }

    private static float getValue(int value, int min, int max) {
        if (min < value) {
            value -= min;
            return (value < max)
                    ? (float) value / (float) max
                    : 1.0f;
        }
        return 0.0f;
    }
}

⏎ javax/swing/colorchooser/DiagramComponent.java

Or download all of them as a single archive file:

File name: jre-rt-javax-1.8.0_191-src.zip
File size: 5381005 bytes
Release date: 2018-10-28
Download 

⇒ JRE 8 rt.jar - org.* Package Source Code

⇐ JRE 8 rt.jar - java.* Package Source Code

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