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/accessibility/AccessibleHypertext.java

/*
 * Copyright (c) 1998, 2000, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javax.accessibility;


import java.util.*;
import java.awt.*;
import javax.swing.text.*;


/**
 * <P>The AccessibleHypertext class is the base class for all
 * classes that present hypertext information on the display.  This class
 * provides the standard mechanism for an assistive technology to access
 * that text via its content, attributes, and spatial location.
 * It also provides standard mechanisms for manipulating hyperlinks.
 * Applications can determine if an object supports the AccessibleHypertext
 * interface by first obtaining its AccessibleContext (see {@link Accessible})
 * and then calling the {@link AccessibleContext#getAccessibleText}
 * method of AccessibleContext.  If the return value is a class which extends
 * AccessibleHypertext, then that object supports AccessibleHypertext.
 *
 * @see Accessible
 * @see Accessible#getAccessibleContext
 * @see AccessibleContext
 * @see AccessibleText
 * @see AccessibleContext#getAccessibleText
 *
 * @author      Peter Korn
 */
public interface AccessibleHypertext extends AccessibleText {

    /**
     * Returns the number of links within this hypertext document.
     *
     * @return number of links in this hypertext doc.
     */
    public abstract int getLinkCount();

    /**
     * Returns the nth Link of this Hypertext document.
     *
     * @param linkIndex within the links of this Hypertext
     * @return Link object encapsulating the nth link(s)
     */
    public abstract AccessibleHyperlink getLink(int linkIndex);

    /**
     * Returns the index into an array of hyperlinks that
     * is associated with this character index, or -1 if there
     * is no hyperlink associated with this index.
     *
     * @param charIndex index within the text
     * @return index into the set of hyperlinks for this hypertext doc.
     */
    public abstract int getLinkIndex(int charIndex);
}

⏎ javax/accessibility/AccessibleHypertext.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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