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/org/apache/xalan/internal/xsltc/DOMEnhancedForDTM.java

/*
 * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DOMEnhancedForDTM.java,v 1.2.4.1 2005/08/31 10:25:13 pvedula Exp $
 */
package com.sun.org.apache.xalan.internal.xsltc;

/**
 * Interface for SAXImpl which adds methods used at run-time, over and above
 * those provided by the XSLTC DOM interface. An attempt to avoid the current
 * "Is the DTM a DOM, if so is it a SAXImpl, . . .
 * which was producing some ugly replicated code
 * and introducing bugs where that multipathing had not been
 * done.  This makes it easier to provide other DOM/DOMEnhancedForDTM
 * implementations, rather than hard-wiring XSLTC to SAXImpl.
 *
 * @author Joseph Kesselman
 *
 */
public interface DOMEnhancedForDTM extends DOM {
    public short[] getMapping(String[] names, String[] uris, int[] types);
    public int[] getReverseMapping(String[] names, String[] uris, int[] types);
    public short[] getNamespaceMapping(String[] namespaces);
    public short[] getReverseNamespaceMapping(String[] namespaces);
    public String getDocumentURI();
    public void setDocumentURI(String uri);
    public int getExpandedTypeID2(int nodeHandle);
    public boolean hasDOMSource();
    public int getElementById(String idString);
}

⏎ com/sun/org/apache/xalan/internal/xsltc/DOMEnhancedForDTM.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
Download 

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