1 /*
2  * Copyright (c) 1999, 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.
8  *
9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 
25 /**
26  * Plain text file handler
27  *
28  * This class provides an example of a a replacement content handler for
29  * the text/plain content type.  It reads the content of the URL, and prepends
30  * an additional message at the beginning.
31  *
32  * Note that the only restrictions on the package/class names are:
33  * 1) the package must end in the major type of the content type (such as
34  *    text, image, application, etc).
35  * 2) the class name must be named with the subtype of the content type (for
36  *    content type "text/plain", this would be "plain" as in this example; for
37  *    content type "image/gif", the class name would be "gif", and the package
38  *    name must end with ".image".
39  * 3) the class must be a subclass of ContentHandler.
40  * 4) It must define the getContent function.
41  */
42 package COM.foo.content.text;
43 
44 import java.net.ContentHandler;
45 import java.io.InputStream;
46 import java.net.URLConnection;
47 import java.io.IOException;
48 
debug(String msg)49 public class plain extends ContentHandler {
50     /**
51      * Returns one of several object types (this set may change in future
52      * versions):
53      * 1) instance of Thread:
54      *    Invoke the thread to launch an external viewer.
55      * 2) instance of InputStream:
56      *    Bring up the "Save to disk" dialog page to allow the content
57      *    to be saved to disk.
58      * 3) instance of InputStreamImageSource:
59      *    Load the image into HotJava in an image viewer page.
60      * 4) instance of String:
61      *    Go to a new page with the string as the plain text content
62      *    of that page.
63      */
64     public Object getContent(URLConnection uc) {
65         try {
66             InputStream is = uc.getInputStream();
67             StringBuffer sb = new StringBuffer();
68             int c;
69 
70             sb.append("[Content of " + uc.getURL() + "]\n\n");
71             sb.append("[This opening message brought to you by your plain/text\n");
72             sb.append("content handler. To remove this content handler, delete the\n");
73             sb.append("COM.foo.content.text directory from your class path and\n");
74             sb.append("the java.content.handler.pkgs property from your HotJava\n");
75             sb.append("properties file.]\n");
76             sb.append("----------------------------------------------------------------\n\n");
77 
78             // Read the characters from the source, accumulate them into the string buffer.
79             // (Not the most efficient, but simplest for this example.)
80             while ((c = is.read()) >= 0) {
81                 sb.append((char)c);
82             }
83 
84             // Tidy up
85             is.close();
86 
87             // Return the resulting string to our client (we're case 4 above)
88             return sb.toString();
89         } catch (IOException e) {
90             // For any exception, just return an indication of what went wrong.
91             return "Problem reading document: " + uc.getURL();
92         }
93     }
94 }
95