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/jmx/snmp/IPAcl/SimpleNode.java

/*
 * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */


/* Generated By:JJTree: Do not edit this line. SimpleNode.java */

package com.sun.jmx.snmp.IPAcl;

import java.net.InetAddress;
import java.util.Hashtable;
import java.util.Vector;

class SimpleNode implements Node {
    protected Node parent;
    protected Node[] children;
    protected int id;
    protected Parser parser;

    public SimpleNode(int i) {
        id = i;
    }

    public SimpleNode(Parser p, int i) {
        this(i);
        parser = p;
    }

    public static Node jjtCreate(int id) {
        return new SimpleNode(id);
    }

    public static Node jjtCreate(Parser p, int id) {
        return new SimpleNode(p, id);
    }

    public void jjtOpen() {
    }

    public void jjtClose() {
    }

    public void jjtSetParent(Node n) { parent = n; }
    public Node jjtGetParent() { return parent; }

    public void jjtAddChild(Node n, int i) {
        if (children == null) {
            children = new Node[i + 1];
        } else if (i >= children.length) {
            Node c[] = new Node[i + 1];
            System.arraycopy(children, 0, c, 0, children.length);
            children = c;
        }
        children[i] = n;
    }

    public Node jjtGetChild(int i) {
        return children[i];
    }

    public int jjtGetNumChildren() {
        return (children == null) ? 0 : children.length;
    }

    /*
      SR. Extend the SimpleNode definition
    */

    /**
     * Build the Trap entries from the syntactic tree.
     */
    public void buildTrapEntries(Hashtable<InetAddress, Vector<String>> dest) {
        if (children != null) {
            for (int i = 0; i < children.length; ++i) {
                SimpleNode n = (SimpleNode)children[i];
                if (n != null) {
                    n.buildTrapEntries(dest);
                }
            } /* end of loop */
        }
    }
    /**
     * Build the Inform entries from the syntactic tree.
     */
    public void buildInformEntries(Hashtable<InetAddress, Vector<String>> dest) {
        if (children != null) {
            for (int i = 0; i < children.length; ++i) {
                SimpleNode n = (SimpleNode)children[i];
                if (n != null) {
                    n.buildInformEntries(dest);
                }
            } /* end of loop */
        }
    }

    /**
     * Build the Acl entries from the syntactic tree.
     */
    public void buildAclEntries(PrincipalImpl owner, AclImpl acl) {
        if (children != null) {
            for (int i = 0; i < children.length; ++i) {
                SimpleNode n = (SimpleNode)children[i];
                if (n != null) {
                    n.buildAclEntries(owner, acl);
                }
            } /* end of loop */
        }
    }

    /* END SR */

    /* You can override these two methods in subclasses of SimpleNode to
       customize the way the node appears when the tree is dumped.  If
       your output uses more than one line you should override
       toString(String), otherwise overriding toString() is probably all
       you need to do. */

    public String toString() { return ParserTreeConstants.jjtNodeName[id]; }
    public String toString(String prefix) { return prefix + toString(); }

    /* Override this method if you want to customize how the node dumps
       out its children. */

    public void dump(String prefix) {
        if (children != null) {
            for (int i = 0; i < children.length; ++i) {
                SimpleNode n = (SimpleNode)children[i];
                if (n != null) {
                    n.dump(prefix + " ");
                }
            }
        }
    }
}

⏎ com/sun/jmx/snmp/IPAcl/SimpleNode.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 

⇒ Backup JDK 8 Installation Directory

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

⇑ Download and Use JDK 8

⇑⇑ FAQ for JDK (Java Development Kit)