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/PortableServer/AdapterActivatorOperations.java

package org.omg.PortableServer;


/**
* org/omg/PortableServer/AdapterActivatorOperations.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/PortableServer/poa.idl
* Saturday, October 6, 2018 9:30:42 AM PDT
*/


/**
	 * An adapter activator supplies a POA with the ability 
	 * to create child POAs on demand, as a side-effect of 
	 * receiving a request that names the child POA 
	 * (or one of its children), or when find_POA is called 
	 * with an activate parameter value of TRUE.
	 */
public interface AdapterActivatorOperations 
{

  /**
	 * This operation is invoked when the ORB receives 
	 * a request for an object reference that identifies 
	 * a target POA that does not exist. The ORB invokes 
	 * this operation once for each POA that must be 
	 * created in order for the target POA to exist.
	 * @param parent indicates the parent POA for the POA
	 *               that needs to be created.
	 * @param name identifies the name of the POA relative to
	 *             the parent.
	 * @return returns TRUE if the POA was created or FALSE
	 *         otherwise.
	 */
  boolean unknown_adapter (org.omg.PortableServer.POA parent, String name);
} // interface AdapterActivatorOperations

⏎ org/omg/PortableServer/AdapterActivatorOperations.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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