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/AccessibleExtendedText.java

/*
 * Copyright (c) 2003, 2006, 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 AccessibleExtendedText interface contains additional methods
 * not provided by the AccessibleText interface
 *
 * Applications can determine if an object supports the AccessibleExtendedText
 * interface by first obtaining its AccessibleContext (see {@link Accessible})
 * and then calling the {@link AccessibleContext#getAccessibleText} method of
 * AccessibleContext.  If the return value is an instance of
 * AccessibleExtendedText, the object supports this interface.
 *
 * @see Accessible
 * @see Accessible#getAccessibleContext
 * @see AccessibleContext
 * @see AccessibleContext#getAccessibleText
 *
 * @author       Peter Korn
 * @author       Lynn Monsanto
 * @since 1.5
 */
public interface AccessibleExtendedText {

    /**
     * Constant used to indicate that the part of the text that should be
     * retrieved is a line of text.
     *
     * @see AccessibleText#getAtIndex
     * @see AccessibleText#getAfterIndex
     * @see AccessibleText#getBeforeIndex
     */
    public static final int LINE = 4; // BugID: 4849720

    /**
     * Constant used to indicate that the part of the text that should be
     * retrieved is contiguous text with the same text attributes.
     *
     * @see AccessibleText#getAtIndex
     * @see AccessibleText#getAfterIndex
     * @see AccessibleText#getBeforeIndex
     */
    public static final int ATTRIBUTE_RUN = 5; // BugID: 4849720

    /**
     * Returns the text between two indices
     *
     * @param startIndex the start index in the text
     * @param endIndex the end index in the text
     * @return the text string if the indices are valid.
     * Otherwise, null is returned.
     */
    public String getTextRange(int startIndex, int endIndex);

    /**
     * Returns the <code>AccessibleTextSequence</code> at a given index.
     *
     * @param part the <code>CHARACTER</code>, <code>WORD</code>,
     * <code>SENTENCE</code>, <code>LINE</code> or <code>ATTRIBUTE_RUN</code>
     * to retrieve
     * @param index an index within the text
     * @return an <code>AccessibleTextSequence</code> specifying the text
     * if part and index are valid.  Otherwise, null is returned.
     *
     * @see AccessibleText#CHARACTER
     * @see AccessibleText#WORD
     * @see AccessibleText#SENTENCE
     */
    public AccessibleTextSequence getTextSequenceAt(int part, int index);

    /**
     * Returns the <code>AccessibleTextSequence</code> after a given index.
     *
     * @param part the <code>CHARACTER</code>, <code>WORD</code>,
     * <code>SENTENCE</code>, <code>LINE</code> or <code>ATTRIBUTE_RUN</code>
     * to retrieve
     * @param index an index within the text
     * @return an <code>AccessibleTextSequence</code> specifying the text
     * if part and index are valid.  Otherwise, null is returned.
     *
     * @see AccessibleText#CHARACTER
     * @see AccessibleText#WORD
     * @see AccessibleText#SENTENCE
     */
    public AccessibleTextSequence getTextSequenceAfter(int part, int index);

    /**
     * Returns the <code>AccessibleTextSequence</code> before a given index.
     *
     * @param part the <code>CHARACTER</code>, <code>WORD</code>,
     * <code>SENTENCE</code>, <code>LINE</code> or <code>ATTRIBUTE_RUN</code>
     * to retrieve
     * @param index an index within the text
     * @return an <code>AccessibleTextSequence</code> specifying the text
     * if part and index are valid.  Otherwise, null is returned.
     *
     * @see AccessibleText#CHARACTER
     * @see AccessibleText#WORD
     * @see AccessibleText#SENTENCE
     */
    public AccessibleTextSequence getTextSequenceBefore(int part, int index);

    /**
     * Returns the bounding rectangle of the text between two indices.
     *
     * @param startIndex the start index in the text
     * @param endIndex the end index in the text
     * @return the bounding rectangle of the text if the indices are valid.
     * Otherwise, null is returned.
     */
    public Rectangle getTextBounds(int startIndex, int endIndex);
}

⏎ javax/accessibility/AccessibleExtendedText.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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