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

⏎ javax/lang/model/element/VariableElement.java

/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.lang.model.element;

import javax.lang.model.util.Elements;

/**
 * Represents a field, {@code enum} constant, method or constructor
 * parameter, local variable, resource variable, or exception
 * parameter.
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ahé
 * @since 1.6
 */
public interface VariableElement extends Element {

    /**
     * Returns the value of this variable if this is a {@code final}
     * field initialized to a compile-time constant.  Returns {@code
     * null} otherwise.  The value will be of a primitive type or a
     * {@code String}.  If the value is of a primitive type, it is
     * wrapped in the appropriate wrapper class (such as {@link
     * Integer}).
     *
     * <p>Note that not all {@code final} fields will have
     * constant values.  In particular, {@code enum} constants are
     * <em>not</em> considered to be compile-time constants.  To have a
     * constant value, a field's type must be either a primitive type
     * or {@code String}.
     *
     * @return the value of this variable if this is a {@code final}
     * field initialized to a compile-time constant, or {@code null}
     * otherwise
     *
     * @see Elements#getConstantExpression(Object)
     * @jls 15.28 Constant Expression
     * @jls 4.12.4 final Variables
     */
    Object getConstantValue();

    /**
     * Returns the simple name of this variable element.
     *
     * <p>For method and constructor parameters, the name of each
     * parameter must be distinct from the names of all other
     * parameters of the same executable.  If the original source
     * names are not available, an implementation may synthesize names
     * subject to the distinctness requirement above.
     *
     * @return the simple name of this variable element
     */
    @Override
    Name getSimpleName();

    /**
     * Returns the enclosing element of this variable.
     *
     * The enclosing element of a method or constructor parameter is
     * the executable declaring the parameter.
     *
     * @return the enclosing element of this variable
     */
    @Override
    Element getEnclosingElement();
}

⏎ javax/lang/model/element/VariableElement.java

Or download all of them as a single archive file:

File name: jre-rt-javax-1.8.0_191-src.zip
File size: 5381005 bytes
Release date: 2018-10-28
Download 

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

⇐ JRE 8 rt.jar - java.* Package Source Code

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