KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > quadcap > io > LogReader


1 package com.quadcap.io;
2
3 /* Copyright 1997 - 2003 Quadcap Software. All rights reserved.
4  *
5  * This software is distributed under the Quadcap Free Software License.
6  * This software may be used or modified for any purpose, personal or
7  * commercial. Open Source redistributions are permitted. Commercial
8  * redistribution of larger works derived from, or works which bundle
9  * this software requires a "Commercial Redistribution License"; see
10  * http://www.quadcap.com/purchase.
11  *
12  * Redistributions qualify as "Open Source" under one of the following terms:
13  *
14  * Redistributions are made at no charge beyond the reasonable cost of
15  * materials and delivery.
16  *
17  * Redistributions are accompanied by a copy of the Source Code or by an
18  * irrevocable offer to provide a copy of the Source Code for up to three
19  * years at the cost of materials and delivery. Such redistributions
20  * must allow further use, modification, and redistribution of the Source
21  * Code under substantially the same terms as this license.
22  *
23  * Redistributions of source code must retain the copyright notices as they
24  * appear in each source code file, these license terms, and the
25  * disclaimer/limitation of liability set forth as paragraph 6 below.
26  *
27  * Redistributions in binary form must reproduce this Copyright Notice,
28  * these license terms, and the disclaimer/limitation of liability set
29  * forth as paragraph 6 below, in the documentation and/or other materials
30  * provided with the distribution.
31  *
32  * The Software is provided on an "AS IS" basis. No warranty is
33  * provided that the Software is free of defects, or fit for a
34  * particular purpose.
35  *
36  * Limitation of Liability. Quadcap Software shall not be liable
37  * for any damages suffered by the Licensee or any third party resulting
38  * from use of the Software.
39  */
40
41 import java.io.IOException JavaDoc;
42 import java.io.Reader JavaDoc;
43 import java.io.Writer JavaDoc;
44
45 import com.quadcap.util.Debug;
46 import com.quadcap.util.Util;
47
48 /**
49  * A filter input stream that tees off input into a log file, with a prefix
50  * identifying the stream.
51  *
52  * @author Stan Bailes
53  */
54
55 public class LogReader extends Reader JavaDoc {
56     Reader JavaDoc in;
57     Writer JavaDoc log;
58     String JavaDoc prefix;
59     boolean bol = true;
60     
61     /**
62      * Construct a new log reader
63      *
64      * @param is the underlying reader
65      * @param log the log stream
66      * @param prefix a string identifying this log stream to be prefixed
67      * to every line output by this filter.
68      */
69     public LogReader(Reader JavaDoc in, Writer JavaDoc log, String JavaDoc prefix) {
70     this.in = in;
71     this.log = log;
72     this.prefix = prefix;
73     }
74
75     /**
76      * Read (and log) a byte
77      *
78      * @exception IOException may be thrown
79      */
80     synchronized public int read() throws IOException JavaDoc {
81     int c = in.read();
82         if (c > 0) {
83             if (bol) log.write(prefix);
84             log.write((char)c);
85         }
86     bol = (c == '\n');
87     return c;
88     }
89
90     /**
91      * Read (and log) an array of bytes
92      */
93     public int read(char[] cbuf, int off, int len) throws IOException JavaDoc {
94         for (int i = 0; i < len; i++) {
95             int c = read();
96             if (c < 0) return i > 0 ? i : -1;
97             cbuf[off + i] = (char)c;
98         }
99         return len > 0 ? len : -1;
100     }
101
102     /**
103      * Close the underlying stream (but not the log stream!)
104      *
105      * @exception IOException may be thrown
106      */
107     public void close() throws IOException JavaDoc {
108     in.close();
109     }
110 }
111
Popular Tags