1 /***
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions are
4 * met :
5 *
6 * . Redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer.
8 *
9 * . Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * . The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $Id: ObjectInput.java,v 1.9 2005/09/10 11:26:47 mat007 Exp $
29 */
30
31 package jtge.engine.io;
32
33 import java.io.EOFException;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectInputStream;
37 import jtge.engine.command.ICommand;
38
39 /***
40 * Provides an input implementation based on object serialization.
41 *
42 * @see <a href="http://java.sun.com/j2se/1.4.2/docs/guide/serialization/spec/input.html">Object Serialization
43 * Specification, Section 3, Object AbstractInput Classes</a>
44 * @author Mathieu Champlon
45 * @version $Revision: 1.9 $ $Date: 2005/09/10 11:26:47 $
46 */
47 public class ObjectInput implements IInputImp
48 {
49 private final InputStream stream;
50 private ObjectInputStream input;
51 private boolean isClosed;
52
53 /***
54 * Create an input.
55 *
56 * @param stream the stream to read data from
57 */
58 public ObjectInput( final InputStream stream )
59 {
60 if( stream == null )
61 throw new IllegalArgumentException( "argument 'stream' is null" );
62 this.stream = stream;
63 isClosed = false;
64 }
65
66 /***
67 * {@inheritDoc}
68 */
69 public final ICommand read()
70 {
71 try
72 {
73 if( input == null )
74 input = new ObjectInputStream( stream );
75 return (ICommand)input.readObject();
76 }
77 catch( EOFException e )
78 {
79 close();
80 return null;
81 }
82 catch( Exception e )
83 {
84 throw new InputOutputException( e );
85 }
86 }
87
88 /***
89 * {@inheritDoc}
90 */
91 public final void close()
92 {
93 isClosed = true;
94 try
95 {
96 if( input != null )
97 input.close();
98 stream.close();
99 }
100 catch( IOException e )
101 {
102 throw new InputOutputException( e );
103 }
104 }
105
106 /***
107 * {@inheritDoc}
108 */
109 public final boolean isClosed()
110 {
111 return isClosed;
112 }
113 }