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/Annotation.java

/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.text;

/**
* An Annotation object is used as a wrapper for a text attribute value if
* the attribute has annotation characteristics. These characteristics are:
* <ul>
* <li>The text range that the attribute is applied to is critical to the
* semantics of the range. That means, the attribute cannot be applied to subranges
* of the text range that it applies to, and, if two adjacent text ranges have
* the same value for this attribute, the attribute still cannot be applied to
* the combined range as a whole with this value.
* <li>The attribute or its value usually do no longer apply if the underlying text is
* changed.
* </ul>
*
* An example is grammatical information attached to a sentence:
* For the previous sentence, you can say that "an example"
* is the subject, but you cannot say the same about "an", "example", or "exam".
* When the text is changed, the grammatical information typically becomes invalid.
* Another example is Japanese reading information (yomi).
*
* <p>
* Wrapping the attribute value into an Annotation object guarantees that
* adjacent text runs don't get merged even if the attribute values are equal,
* and indicates to text containers that the attribute should be discarded if
* the underlying text is modified.
*
* @see AttributedCharacterIterator
* @since 1.2
*/

public class Annotation {

    /**
     * Constructs an annotation record with the given value, which
     * may be null.
     *
     * @param value the value of the attribute
     */
    public Annotation(Object value) {
        this.value = value;
    }

    /**
     * Returns the value of the attribute, which may be null.
     *
     * @return the value of the attribute
     */
    public Object getValue() {
        return value;
    }

    /**
     * Returns the String representation of this Annotation.
     *
     * @return the {@code String} representation of this {@code Annotation}
     */
    public String toString() {
        return getClass().getName() + "[value=" + value + "]";
    }

    private Object value;

};

⏎ java/text/Annotation.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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