/*

 * Copyright 1996-1999 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

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 {

    /**

     * 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;

}