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      1 /*
      2  * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved.
      3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
      4  *
      5  * This code is free software; you can redistribute it and/or modify it
      6  * under the terms of the GNU General Public License version 2 only, as
      7  * published by the Free Software Foundation.  Oracle designates this
      8  * particular file as subject to the "Classpath" exception as provided
      9  * by Oracle in the LICENSE file that accompanied this code.
     10  *
     11  * This code is distributed in the hope that it will be useful, but WITHOUT
     12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     14  * version 2 for more details (a copy is included in the LICENSE file that
     15  * accompanied this code).
     16  *
     17  * You should have received a copy of the GNU General Public License version
     18  * 2 along with this work; if not, write to the Free Software Foundation,
     19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
     20  *
     21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
     22  * or visit www.oracle.com if you need additional information or have any
     23  * questions.
     24  */
     25 
     26 package java.io;
     27 
     28 /**
     29  * ObjectInput extends the DataInput interface to include the reading of
     30  * objects. DataInput includes methods for the input of primitive types,
     31  * ObjectInput extends that interface to include objects, arrays, and Strings.
     32  *
     33  * @author  unascribed
     34  * @see java.io.InputStream
     35  * @see java.io.ObjectOutputStream
     36  * @see java.io.ObjectInputStream
     37  * @since   JDK1.1
     38  */
     39 public interface ObjectInput extends DataInput, AutoCloseable {
     40     /**
     41      * Read and return an object. The class that implements this interface
     42      * defines where the object is "read" from.
     43      *
     44      * @return the object read from the stream
     45      * @exception java.lang.ClassNotFoundException If the class of a serialized
     46      *      object cannot be found.
     47      * @exception IOException If any of the usual Input/Output
     48      * related exceptions occur.
     49      */
     50     public Object readObject()
     51         throws ClassNotFoundException, IOException;
     52 
     53     /**
     54      * Reads a byte of data. This method will block if no input is
     55      * available.
     56      * @return  the byte read, or -1 if the end of the
     57      *          stream is reached.
     58      * @exception IOException If an I/O error has occurred.
     59      */
     60     public int read() throws IOException;
     61 
     62     /**
     63      * Reads into an array of bytes.  This method will
     64      * block until some input is available.
     65      * @param b the buffer into which the data is read
     66      * @return  the actual number of bytes read, -1 is
     67      *          returned when the end of the stream is reached.
     68      * @exception IOException If an I/O error has occurred.
     69      */
     70     public int read(byte b[]) throws IOException;
     71 
     72     /**
     73      * Reads into an array of bytes.  This method will
     74      * block until some input is available.
     75      * @param b the buffer into which the data is read
     76      * @param off the start offset of the data
     77      * @param len the maximum number of bytes read
     78      * @return  the actual number of bytes read, -1 is
     79      *          returned when the end of the stream is reached.
     80      * @exception IOException If an I/O error has occurred.
     81      */
     82     public int read(byte b[], int off, int len) throws IOException;
     83 
     84     /**
     85      * Skips n bytes of input.
     86      * @param n the number of bytes to be skipped
     87      * @return  the actual number of bytes skipped.
     88      * @exception IOException If an I/O error has occurred.
     89      */
     90     public long skip(long n) throws IOException;
     91 
     92     /**
     93      * Returns the number of bytes that can be read
     94      * without blocking.
     95      * @return the number of available bytes.
     96      * @exception IOException If an I/O error has occurred.
     97      */
     98     public int available() throws IOException;
     99 
    100     /**
    101      * Closes the input stream. Must be called
    102      * to release any resources associated with
    103      * the stream.
    104      * @exception IOException If an I/O error has occurred.
    105      */
    106     public void close() throws IOException;
    107 }
    108