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 }