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/lang/IllegalAccessException.java

/*
 * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package java.lang;

/**
 * An IllegalAccessException is thrown when an application tries
 * to reflectively create an instance (other than an array),
 * set or get a field, or invoke a method, but the currently
 * executing method does not have access to the definition of
 * the specified class, field, method or constructor.
 *
 * @author  unascribed
 * @see     Class#newInstance()
 * @see     java.lang.reflect.Field#set(Object, Object)
 * @see     java.lang.reflect.Field#setBoolean(Object, boolean)
 * @see     java.lang.reflect.Field#setByte(Object, byte)
 * @see     java.lang.reflect.Field#setShort(Object, short)
 * @see     java.lang.reflect.Field#setChar(Object, char)
 * @see     java.lang.reflect.Field#setInt(Object, int)
 * @see     java.lang.reflect.Field#setLong(Object, long)
 * @see     java.lang.reflect.Field#setFloat(Object, float)
 * @see     java.lang.reflect.Field#setDouble(Object, double)
 * @see     java.lang.reflect.Field#get(Object)
 * @see     java.lang.reflect.Field#getBoolean(Object)
 * @see     java.lang.reflect.Field#getByte(Object)
 * @see     java.lang.reflect.Field#getShort(Object)
 * @see     java.lang.reflect.Field#getChar(Object)
 * @see     java.lang.reflect.Field#getInt(Object)
 * @see     java.lang.reflect.Field#getLong(Object)
 * @see     java.lang.reflect.Field#getFloat(Object)
 * @see     java.lang.reflect.Field#getDouble(Object)
 * @see     java.lang.reflect.Method#invoke(Object, Object[])
 * @see     java.lang.reflect.Constructor#newInstance(Object[])
 * @since   JDK1.0
 */
public class IllegalAccessException extends ReflectiveOperationException {
    private static final long serialVersionUID = 6616958222490762034L;

    /**
     * Constructs an <code>IllegalAccessException</code> without a
     * detail message.
     */
    public IllegalAccessException() {
        super();
    }

    /**
     * Constructs an <code>IllegalAccessException</code> with a detail message.
     *
     * @param   s   the detail message.
     */
    public IllegalAccessException(String s) {
        super(s);
    }
}

⏎ java/lang/IllegalAccessException.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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