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/io/ObjectInput.java

/*
 * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package java.io;

/**
 * ObjectInput extends the DataInput interface to include the reading of
 * objects. DataInput includes methods for the input of primitive types,
 * ObjectInput extends that interface to include objects, arrays, and Strings.
 *
 * @author  unascribed
 * @see java.io.InputStream
 * @see java.io.ObjectOutputStream
 * @see java.io.ObjectInputStream
 * @since   JDK1.1
 */
public interface ObjectInput extends DataInput, AutoCloseable {
    /**
     * Read and return an object. The class that implements this interface
     * defines where the object is "read" from.
     *
     * @return the object read from the stream
     * @exception java.lang.ClassNotFoundException If the class of a serialized
     *      object cannot be found.
     * @exception IOException If any of the usual Input/Output
     * related exceptions occur.
     */
    public Object readObject()
        throws ClassNotFoundException, IOException;

    /**
     * Reads a byte of data. This method will block if no input is
     * available.
     * @return  the byte read, or -1 if the end of the
     *          stream is reached.
     * @exception IOException If an I/O error has occurred.
     */
    public int read() throws IOException;

    /**
     * Reads into an array of bytes.  This method will
     * block until some input is available.
     * @param b the buffer into which the data is read
     * @return  the actual number of bytes read, -1 is
     *          returned when the end of the stream is reached.
     * @exception IOException If an I/O error has occurred.
     */
    public int read(byte b[]) throws IOException;

    /**
     * Reads into an array of bytes.  This method will
     * block until some input is available.
     * @param b the buffer into which the data is read
     * @param off the start offset of the data
     * @param len the maximum number of bytes read
     * @return  the actual number of bytes read, -1 is
     *          returned when the end of the stream is reached.
     * @exception IOException If an I/O error has occurred.
     */
    public int read(byte b[], int off, int len) throws IOException;

    /**
     * Skips n bytes of input.
     * @param n the number of bytes to be skipped
     * @return  the actual number of bytes skipped.
     * @exception IOException If an I/O error has occurred.
     */
    public long skip(long n) throws IOException;

    /**
     * Returns the number of bytes that can be read
     * without blocking.
     * @return the number of available bytes.
     * @exception IOException If an I/O error has occurred.
     */
    public int available() throws IOException;

    /**
     * Closes the input stream. Must be called
     * to release any resources associated with
     * the stream.
     * @exception IOException If an I/O error has occurred.
     */
    public void close() throws IOException;
}

⏎ java/io/ObjectInput.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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