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

⏎ org/w3c/dom/html/HTMLCollection.java

/*
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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/*
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 * Copyright (c) 2000 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See W3C License http://www.w3.org/Consortium/Legal/ for more
 * details.
 */

package org.w3c.dom.html;

import org.w3c.dom.Node;

/**
 *  An <code>HTMLCollection</code> is a list of nodes. An individual node may
 * be accessed by either ordinal index or the node's<code>name</code> or
 * <code>id</code> attributes.  Note: Collections in the HTML DOM are assumed
 * to be  live meaning that they are automatically updated when the
 * underlying document is changed.
 * <p>See also the <a href='http://www.w3.org/TR/2000/CR-DOM-Level-2-20000510'>Document Object Model (DOM) Level 2 Specification</a>.
 */
public interface HTMLCollection {
    /**
     *  This attribute specifies the length or  size of the list.
     */
    public int getLength();

    /**
     *  This method retrieves a node specified by ordinal index. Nodes are
     * numbered in tree order (depth-first traversal order).
     * @param index  The index of the node to be fetched. The index origin is
     *   0.
     * @return  The <code>Node</code> at the corresponding position upon
     *   success. A value of <code>null</code> is returned if the index is
     *   out of range.
     */
    public Node item(int index);

    /**
     *  This method retrieves a <code>Node</code> using a name. It first
     * searches for a <code>Node</code> with a matching <code>id</code>
     * attribute. If it doesn't find one, it then searches for a
     * <code>Node</code> with a matching <code>name</code> attribute, but
     * only on those elements that are allowed a name attribute.
     * @param name  The name of the <code>Node</code> to be fetched.
     * @return  The <code>Node</code> with a <code>name</code> or
     *   <code>id</code> attribute whose value corresponds to the specified
     *   string. Upon failure (e.g., no node with this name exists), returns
     *   <code>null</code> .
     */
    public Node namedItem(String name);

}

⏎ org/w3c/dom/html/HTMLCollection.java

Or download all of them as a single archive file:

File name: jre-rt-org-1.8.0_191-src.zip
File size: 951125 bytes
Release date: 2018-10-28
Download 

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

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

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