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/omg/IOP/TAG_INTERNET_IOP.java

package org.omg.IOP;


/**
* org/omg/IOP/TAG_INTERNET_IOP.java .
* Generated by the IDL-to-Java compiler (portable), version "3.2"
* from c:/re/workspace/8-2-build-windows-amd64-cygwin/jdk8u191/11896/corba/src/share/classes/org/omg/PortableInterceptor/IOP.idl
* Saturday, October 6, 2018 9:30:42 AM PDT
*/

public interface TAG_INTERNET_IOP
{

  /**
     * Identifies profiles that 
     * support the Internet Inter-ORB Protocol. The <code>ProfileBody</code>
     * of this profile contains a CDR encapsulation of a structure 
     * containing addressing and object identification information used by 
     * IIOP. Version 1.1 of the <code>TAG_INTERNET_IOP</code> profile 
     * also includes an array of TaggedComponent objects that can 
     * contain additional information supporting optional IIOP features, 
     * ORB services such as security, and future protocol extensions. 
     * <p>
     * Protocols other than IIOP (such as ESIOPs and other GIOPs) can share 
     * profile information (such as object identity or security 
     * information) with IIOP by encoding their additional profile information 
     * as components in the <code>TAG_INTERNET_IOP</code> profile. All 
     * <code>TAG_INTERNET_IOP</code> profiles support IIOP, regardless of 
     * whether they also support additional protocols. Interoperable 
     * ORBs are not required to create or understand any other profile, 
     * nor are they required to create or understand any of the components 
     * defined for other protocols that might share the 
     * <code>TAG_INTERNET_IOP</code> profile with IIOP. 
     * <p>
     * The <code>profile_data</code> for the <code>TAG_INTERNET_IOP</code> 
     * profile is a CDR encapsulation of the <code>IIOP.ProfileBody_1_1</code>
     * type.
     */
  public static final int value = (int)(0L);
}

⏎ org/omg/IOP/TAG_INTERNET_IOP.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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