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/beans/ThreadGroupContext.java

/*
 * Copyright (c) 2011, 2013, 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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 */

package java.beans;

import com.sun.beans.finder.BeanInfoFinder;
import com.sun.beans.finder.PropertyEditorFinder;

import java.awt.GraphicsEnvironment;
import java.util.Map;
import java.util.WeakHashMap;

/**
 * The {@code ThreadGroupContext} is an application-dependent
 * context referenced by the specific {@link ThreadGroup}.
 * This is a replacement for the {@link sun.awt.AppContext}.
 *
 * @author  Sergey Malenkov
 */
final class ThreadGroupContext {

    private static final WeakIdentityMap<ThreadGroupContext> contexts = new WeakIdentityMap<ThreadGroupContext>() {
        protected ThreadGroupContext create(Object key) {
            return new ThreadGroupContext();
        }
    };

    /**
     * Returns the appropriate {@code ThreadGroupContext} for the caller,
     * as determined by its {@code ThreadGroup}.
     *
     * @return  the application-dependent context
     */
    static ThreadGroupContext getContext() {
        return contexts.get(Thread.currentThread().getThreadGroup());
    }

    private volatile boolean isDesignTime;
    private volatile Boolean isGuiAvailable;

    private Map<Class<?>, BeanInfo> beanInfoCache;
    private BeanInfoFinder beanInfoFinder;
    private PropertyEditorFinder propertyEditorFinder;

    private ThreadGroupContext() {
    }

    boolean isDesignTime() {
        return this.isDesignTime;
    }

    void setDesignTime(boolean isDesignTime) {
        this.isDesignTime = isDesignTime;
    }


    boolean isGuiAvailable() {
        Boolean isGuiAvailable = this.isGuiAvailable;
        return (isGuiAvailable != null)
                ? isGuiAvailable.booleanValue()
                : !GraphicsEnvironment.isHeadless();
    }

    void setGuiAvailable(boolean isGuiAvailable) {
        this.isGuiAvailable = Boolean.valueOf(isGuiAvailable);
    }


    BeanInfo getBeanInfo(Class<?> type) {
        return (this.beanInfoCache != null)
                ? this.beanInfoCache.get(type)
                : null;
    }

    BeanInfo putBeanInfo(Class<?> type, BeanInfo info) {
        if (this.beanInfoCache == null) {
            this.beanInfoCache = new WeakHashMap<>();
        }
        return this.beanInfoCache.put(type, info);
    }

    void removeBeanInfo(Class<?> type) {
        if (this.beanInfoCache != null) {
            this.beanInfoCache.remove(type);
        }
    }

    void clearBeanInfoCache() {
        if (this.beanInfoCache != null) {
            this.beanInfoCache.clear();
        }
    }


    synchronized BeanInfoFinder getBeanInfoFinder() {
        if (this.beanInfoFinder == null) {
            this.beanInfoFinder = new BeanInfoFinder();
        }
        return this.beanInfoFinder;
    }

    synchronized PropertyEditorFinder getPropertyEditorFinder() {
        if (this.propertyEditorFinder == null) {
            this.propertyEditorFinder = new PropertyEditorFinder();
        }
        return this.propertyEditorFinder;
    }
}

⏎ java/beans/ThreadGroupContext.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 

⇒ JRE 8 rt.jar - javax.* Package Source Code

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