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/awt/AttributeValue.java

/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.awt;

import sun.util.logging.PlatformLogger;

abstract class AttributeValue {
    private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.AttributeValue");
    private final int value;
    private final String[] names;

    protected AttributeValue(int value, String[] names) {
        if (log.isLoggable(PlatformLogger.Level.FINEST)) {
            log.finest("value = " + value + ", names = " + names);
        }

        if (log.isLoggable(PlatformLogger.Level.FINER)) {
            if ((value < 0) || (names == null) || (value >= names.length)) {
                log.finer("Assertion failed");
            }
        }
        this.value = value;
        this.names = names;
    }
    // This hashCode is used by the sun.awt implementation as an array
    // index.
    public int hashCode() {
        return value;
    }
    public String toString() {
        return names[value];
    }
}

⏎ java/awt/AttributeValue.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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