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Java > Open Source Codes > nextapp > echo2 > webcontainer > image > AwtImageService


1 /*
2  * This file is part of the Echo Web Application Framework (hereinafter "Echo").
3  * Copyright (C) 2002-2005 NextApp, Inc.
4  *
5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6  *
7  * The contents of this file are subject to the Mozilla Public License Version
8  * 1.1 (the "License"); you may not use this file except in compliance with
9  * the License. You may obtain a copy of the License at
10  * http://www.mozilla.org/MPL/
11  *
12  * Software distributed under the License is distributed on an "AS IS" basis,
13  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14  * for the specific language governing rights and limitations under the
15  * License.
16  *
17  * Alternatively, the contents of this file may be used under the terms of
18  * either the GNU General Public License Version 2 or later (the "GPL"), or
19  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
20  * in which case the provisions of the GPL or the LGPL are applicable instead
21  * of those above. If you wish to allow use of your version of this file only
22  * under the terms of either the GPL or the LGPL, and not to allow others to
23  * use your version of this file under the terms of the MPL, indicate your
24  * decision by deleting the provisions above and replace them with the notice
25  * and other provisions required by the GPL or the LGPL. If you do not delete
26  * the provisions above, a recipient may use your version of this file under
27  * the terms of any one of the MPL, the GPL or the LGPL.
28  */
29
30 package nextapp.echo2.webcontainer.image;
31
32 import java.io.IOException JavaDoc;
33 import nextapp.echo2.app.AwtImageReference;
34 import nextapp.echo2.app.ImageReference;
35 import nextapp.echo2.webrender.Connection;
36 import nextapp.echo2.webrender.ContentType;
37 import nextapp.echo2.webrender.WebRenderServlet;
38
39 /**
40  * Renders an <code>AwtImageReference</code> to the client.
41  */
42 public class AwtImageService extends AbstractImageService {
43     
44     private static final String JavaDoc SERVICE_ID = "Echo.AwtImage";
45     
46     public static final AwtImageService INSTANCE = new AwtImageService();
47
48     static {
49         WebRenderServlet.getServiceRegistry().add(INSTANCE);
50     }
51
52     /**
53      * @see nextapp.echo2.webrender.Service#getId()
54      */
55     public String JavaDoc getId() {
56         return SERVICE_ID;
57     }
58     
59     /**
60      * @see nextapp.echo2.webrender.Service#getVersion()
61      */
62     public int getVersion() {
63         return 0; // Enable caching.
64 }
65
66     /**
67      * @see nextapp.echo2.webcontainer.image.AbstractImageService#renderImage(
68      * nextapp.echo2.webrender.Connection, nextapp.echo2.app.ImageReference)
69      */
70     public void renderImage(Connection conn, ImageReference imageReference)
71     throws IOException JavaDoc {
72         try {
73             if (!(imageReference instanceof AwtImageReference)) {
74                 throw new IOException JavaDoc("Image is not an AwtImageReference.");
75             }
76             PngEncoder encoder = new PngEncoder(((AwtImageReference) imageReference).getImage(), true, null, 3);
77             conn.setContentType(ContentType.IMAGE_PNG);
78             encoder.encode(conn.getOutputStream());
79         } catch (IOException JavaDoc ex) {
80             // Internet Explorer appears to enjoy making half-hearted requests for images, wherein it resets the connection
81 // leaving us with an IOException. This exception is silently eaten.
82 }
83     }
84 }
85
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