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

⏎ java/nio/channels/CompletionHandler.java

/*
 * Copyright (c) 2007, 2009, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.nio.channels;

/**
 * A handler for consuming the result of an asynchronous I/O operation.
 *
 * <p> The asynchronous channels defined in this package allow a completion
 * handler to be specified to consume the result of an asynchronous operation.
 * The {@link #completed completed} method is invoked when the I/O operation
 * completes successfully. The {@link #failed failed} method is invoked if the
 * I/O operations fails. The implementations of these methods should complete
 * in a timely manner so as to avoid keeping the invoking thread from dispatching
 * to other completion handlers.
 *
 * @param   <V>     The result type of the I/O operation
 * @param   <A>     The type of the object attached to the I/O operation
 *
 * @since 1.7
 */

public interface CompletionHandler<V,A> {

    /**
     * Invoked when an operation has completed.
     *
     * @param   result
     *          The result of the I/O operation.
     * @param   attachment
     *          The object attached to the I/O operation when it was initiated.
     */
    void completed(V result, A attachment);

    /**
     * Invoked when an operation fails.
     *
     * @param   exc
     *          The exception to indicate why the I/O operation failed
     * @param   attachment
     *          The object attached to the I/O operation when it was initiated.
     */
    void failed(Throwable exc, A attachment);
}

⏎ java/nio/channels/CompletionHandler.java

Or download all of them as a single archive file:

File name: jre-rt-java-1.8.0_191-src.zip
File size: 6664831 bytes
Release date: 2018-10-28
Download 

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