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/type/ExecutableType.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.type;


import java.util.List;

import javax.lang.model.element.ExecutableElement;

/**
 * Represents the type of an executable.  An <i>executable</i>
 * is a method, constructor, or initializer.
 *
 * <p> The executable is
 * represented as when viewed as a method (or constructor or
 * initializer) of some reference type.
 * If that reference type is parameterized, then its actual
 * type arguments are substituted into any types returned by the methods of
 * this interface.
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ah&eacute;
 * @see ExecutableElement
 * @since 1.6
 */
public interface ExecutableType extends TypeMirror {

    /**
     * Returns the type variables declared by the formal type parameters
     * of this executable.
     *
     * @return the type variables declared by the formal type parameters,
     *          or an empty list if there are none
     */
    List<? extends TypeVariable> getTypeVariables();

    /**
     * Returns the return type of this executable.
     * Returns a {@link NoType} with kind {@link TypeKind#VOID VOID}
     * if this executable is not a method, or is a method that does not
     * return a value.
     *
     * @return the return type of this executable
     */
    TypeMirror getReturnType();

    /**
     * Returns the types of this executable's formal parameters.
     *
     * @return the types of this executable's formal parameters,
     *          or an empty list if there are none
     */
    List<? extends TypeMirror> getParameterTypes();

    /**
     * Returns the receiver type of this executable,
     * or {@link javax.lang.model.type.NoType NoType} with
     * kind {@link javax.lang.model.type.TypeKind#NONE NONE}
     * if the executable has no receiver type.
     *
     * An executable which is an instance method, or a constructor of an
     * inner class, has a receiver type derived from the {@linkplain
     * ExecutableElement#getEnclosingElement declaring type}.
     *
     * An executable which is a static method, or a constructor of a
     * non-inner class, or an initializer (static or instance), has no
     * receiver type.
     *
     * @return the receiver type of this executable
     * @since 1.8
     */
    TypeMirror getReceiverType();

    /**
     * Returns the exceptions and other throwables listed in this
     * executable's {@code throws} clause.
     *
     * @return the exceptions and other throwables listed in this
     *          executable's {@code throws} clause,
     *          or an empty list if there are none.
     */
    List<? extends TypeMirror> getThrownTypes();
}

⏎ javax/lang/model/type/ExecutableType.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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