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/text/spi/DecimalFormatSymbolsProvider.java

/*
 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
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 *
 *
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 *
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 */

package java.text.spi;

import java.text.DecimalFormatSymbols;
import java.util.Locale;
import java.util.spi.LocaleServiceProvider;

/**
 * An abstract class for service providers that
 * provide instances of the
 * {@link java.text.DecimalFormatSymbols DecimalFormatSymbols} class.
 *
 * <p>The requested {@code Locale} may contain an <a
 * href="../../util/Locale.html#def_locale_extension"> extension</a> for
 * specifying the desired numbering system. For example, {@code "ar-u-nu-arab"}
 * (in the BCP 47 language tag form) specifies Arabic with the Arabic-Indic
 * digits and symbols, while {@code "ar-u-nu-latn"} specifies Arabic with the
 * Latin digits and symbols. Refer to the <em>Unicode Locale Data Markup
 * Language (LDML)</em> specification for numbering systems.
 *
 * @since        1.6
 * @see Locale#forLanguageTag(String)
 * @see Locale#getExtension(char)
 */
public abstract class DecimalFormatSymbolsProvider extends LocaleServiceProvider {

    /**
     * Sole constructor.  (For invocation by subclass constructors, typically
     * implicit.)
     */
    protected DecimalFormatSymbolsProvider() {
    }

    /**
     * Returns a new <code>DecimalFormatSymbols</code> instance for the
     * specified locale.
     *
     * @param locale the desired locale
     * @exception NullPointerException if <code>locale</code> is null
     * @exception IllegalArgumentException if <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @return a <code>DecimalFormatSymbols</code> instance.
     * @see java.text.DecimalFormatSymbols#getInstance(java.util.Locale)
     */
    public abstract DecimalFormatSymbols getInstance(Locale locale);
}

⏎ java/text/spi/DecimalFormatSymbolsProvider.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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