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1   /*
2    * $Source: /usr/cvsroot/melati/melati/src/main/java/org/melati/util/MelatiWriter.java,v $
3    * $Revision: 1.14 $
4    *
5    * Copyright (C) 2000 Tim Joyce
6    *
7    * Part of Melati (http://melati.org), a framework for the rapid
8    * development of clean, maintainable web applications.
9    *
10   * Melati is free software; Permission is granted to copy, distribute
11   * and/or modify this software under the terms either:
12   *
13   * a) the GNU General Public License as published by the Free Software
14   *    Foundation; either version 2 of the License, or (at your option)
15   *    any later version,
16   *
17   *    or
18   *
19   * b) any version of the Melati Software License, as published
20   *    at http://melati.org
21   *
22   * You should have received a copy of the GNU General Public License and
23   * the Melati Software License along with this program;
24   * if not, write to the Free Software Foundation, Inc.,
25   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26   * GNU General Public License and visit http://melati.org to obtain the
27   * Melati Software License.
28   *
29   * Feel free to contact the Developers of Melati (http://melati.org),
30   * if you would like to work out a different arrangement than the options
31   * outlined here.  It is our intention to allow Melati to be used by as
32   * wide an audience as possible.
33   *
34   * This program is distributed in the hope that it will be useful,
35   * but WITHOUT ANY WARRANTY; without even the implied warranty of
36   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37   * GNU General Public License for more details.
38   *
39   * Contact details for copyright holder:
40   *
41   *     Tim Joyce <timj At paneris.org>
42   */
43  
44  package org.melati.util;
45  
46  import java.io.IOException;
47  import java.io.Writer;
48  import java.io.PrintWriter;
49  
50  /**
51   * An abstract <code>Writer</code> for objects that output from Melati.
52   */
53  
54  public abstract class MelatiWriter extends Writer {
55  
56    protected Writer out;
57    protected boolean flush = false;
58    // the flusher sends output to the client every x seconds
59    private Flusher flusher = null;
60    
61    /**
62     * Set flushing true.
63     */
64    public void setFlushingOn() {
65      flush = true;
66    }
67    
68    /**
69     * {@inheritDoc}
70     * @see java.io.Writer#write(char[], int, int)
71     */
72    public void write(char cbuf[], int off, int len) throws IOException {
73      out.write(cbuf, off, len);
74      startFlushing();
75    }
76    
77    /**
78     * {@inheritDoc}
79     * @see java.io.Writer#write(java.lang.String)
80     */
81    public void write(String string) throws IOException {
82      out.write(string);
83    }
84    
85    protected void startFlushing() {
86      if (flush && flusher == null) {
87        flusher = new Flusher(this);
88        flusher.start();
89      }
90    }
91  
92    /**
93     * {@inheritDoc}
94     * @see java.io.Writer#flush()
95     */
96    public void flush() throws IOException {
97      out.flush();
98    }
99  
100   /**
101    * Hook for extension.
102    */
103   public void reset() throws IOException {
104     if (false) // Flaming clever IDEs 
105       throw new IOException();
106   }
107 
108   /**
109    * {@inheritDoc}
110    * @see java.io.Writer#close()
111    */
112   public void close() throws IOException {
113     out.close();
114     if (flusher != null) flusher.setStopTask(true);
115   }
116 
117   /**
118    * @return a PrintWriter from the output
119    */
120   public PrintWriter getPrintWriter()  {
121     return new PrintWriter(out);
122   }
123   /**
124    * @return a PrintWriter from the output
125    */
126   public Writer getWriter()  {
127     return out;
128   }
129 
130 }