Source code: org/apache/log4j/DailyFileAppender1.java
1 /*
2 * Copyright (C) The Apache Software Foundation. All rights reserved.
3 *
4 * This software is published under the terms of the Apache Software
5 * License version 1.1, a copy of which has been included with this
6 * distribution in the LICENSE.APL file. */
7
8
9
10 package org.apache.log4j;
11
12 import java.io.IOException;
13 import java.io.Writer;
14 import java.io.FileWriter;
15 import java.io.File;
16 import java.io.OutputStream;
17 import java.io.OutputStreamWriter;
18 import java.text.SimpleDateFormat;
19 import java.util.Date;
20 import org.apache.log4j.helpers.OptionConverter;
21 import org.apache.log4j.helpers.QuietWriter;
22 import org.apache.log4j.helpers.CountingQuietWriter;
23 import org.apache.log4j.spi.LoggingEvent;
24 import org.apache.log4j.spi.ErrorCode;
25
26 /**
27 DailyFileAppender extends FileAppender to use filenames formatted with
28 date/time information. The filename is recomputed every day at midnight.
29 Note that the filename doesn't have to change every day, making it possible
30 to have logfiles which are per-week or per-month.
31
32 The appender computes the proper filename using the formats specified in
33 <a href="http://java.sun.com/j2se/1.3/docs/api/java/text/SimpleDateFormat.html">
34 java.text.SimpleDateFormat</a>. The format requires that most static text is
35 enclosed in single quotes, which are removed. The examples below show how
36 quotes are used to embed static information in the format.
37
38 Sample filenames:
39
40 <code>
41 Filename pattern Filename
42 "'/logs/trace-'yyyy-MM-dd'.log'" /logs/trace-2000-12-31.log
43 "'/logs/trace-'yyyy-ww'.log'" /logs/trace-2000-52.log
44 </code>
45
46 @author <a HREF="mailto:eirik.lygre@evita.no">Eirik Lygre</a>
47 */
48 public class DailyFileAppender extends FileAppender {
49
50 /**
51 A string constant used in naming the option for setting the
52 filename pattern. Current value of this string constant is
53 <strong>FileNamePattern</strong>.
54 */
55 static final public String FILE_NAME_PATTERN_OPTION = "FilePattern";
56
57 /**
58 The filename pattern
59 */
60 private String fileNamePattern = null;
61
62 /**
63 The actual formatted filename that is currently being written to
64 */
65 private String currentFileName = null;
66
67 /**
68 The timestamp when we shall next recompute the filename
69 */
70 private long nextFilenameComputingMillis = System.currentTimeMillis () - 1;
71
72 /**
73 The default constructor does no longer set a default layout nor a
74 default output target. */
75 public
76 DailyFileAppender() {
77 }
78
79 /**
80 Instantiate a RollingFileAppender and open the file designated by
81 <code>filename</code>. The opened filename will become the ouput
82 destination for this appender.
83
84 <p>If the <code>append</code> parameter is true, the file will be
85 appended to. Otherwise, the file desginated by
86 <code>filename</code> will be truncated before being opened.
87 */
88 public DailyFileAppender (Layout layout,String filename,boolean append) throws IOException {
89 super(layout, filename, append);
90 }
91
92 /**
93 Instantiate a FileAppender and open the file designated by
94 <code>filename</code>. The opened filename will become the output
95 destination for this appender.
96
97 <p>The file will be appended to. */
98 public DailyFileAppender (Layout layout,String filename) throws IOException {
99 super(layout, filename);
100 }
101
102 /**
103 Set the current output file.
104
105 The function will compute a new filename, and open a new file only
106 when the name has changed.
107
108 The function is automatically called once a day, to allow for
109 daily files -- the purpose of this class.
110 */
111
112 public
113 synchronized
114 void setFile(String fileName, boolean append) throws IOException {
115
116 /* Compute filename, but only if fileNamePattern is specified */
117 if (fileNamePattern == null) {
118 errorHandler.error("Missing file pattern (" + FILE_NAME_PATTERN_OPTION + ") in setFile().");
119 return;
120 }
121
122 Date now = new Date();
123
124 fileName = new SimpleDateFormat(fileNamePattern).format (now);
125 if (fileName.equals(currentFileName))
126 return;
127
128 /* Set up next filename checkpoint */
129 DailyFileAppenderCalendar c = new DailyFileAppenderCalendar();
130 c.rollToNextDay ();
131 nextFilenameComputingMillis = c.getTimeInMillis ();
132
133 currentFileName = fileName;
134
135 super.setFile(fileName, append);
136 }
137
138 /**
139 This method differentiates RollingFileAppender from its super
140 class.
141
142 */
143 protected
144 void subAppend(LoggingEvent event) {
145
146 if (System.currentTimeMillis () >= nextFilenameComputingMillis) {
147 try {
148 setFile (super.fileName, super.fileAppend);
149 }
150 catch(IOException e) {
151 System.err.println("setFile(null, false) call failed.");
152 e.printStackTrace();
153 }
154 }
155
156 super.subAppend(event);
157 }
158
159 /**
160 Retuns the option names for this component, namely {@link
161 #FILE_NAME_PATTERN_OPTION} in
162 addition to the options of {@link FileAppender#getOptionStrings
163 FileAppender}.
164 */
165 public
166 String[] getOptionStrings() {
167
168 return OptionConverter.concatanateArrays(super.getOptionStrings(),
169 new String[] {FILE_NAME_PATTERN_OPTION});
170 }
171
172 /**
173 Set the options for the appender
174 */
175 public
176 void setOption(String key, String value) {
177 super.setOption(key, value);
178 if(key.equalsIgnoreCase(FILE_NAME_PATTERN_OPTION)) {
179 fileNamePattern = value;
180 }
181 }
182
183 /**
184 If the a value for {@link #FILE_OPTION} is non-null, then {@link
185 #setFile} is called with the values of {@link #FILE_OPTION} and
186 {@link #APPEND_OPTION}.
187
188 @since 0.8.1 */
189 public
190 void activateOptions() {
191 try {
192 setFile(null, super.fileAppend);
193 }
194 catch(java.io.IOException e) {
195 errorHandler.error("setFile(null,"+fileAppend+") call failed.",
196 e, ErrorCode.FILE_OPEN_FAILURE);
197 }
198 }
199 }
200
201 /**
202 DailyFileAppenderCalendar is a helper class to DailyFileAppender. Using
203 this class, it is easy to compute and access the next Millis()
204
205 It subclasses the standard
206 <a href="http://java.sun.com/j2se/1.3/docs/api/java/text/GregorianCalendar.html">
207 java.util.GregorianCalendar</a>-object, to allow access to the protected
208 function getTimeInMillis(), which it then exports.
209
210 @author <a HREF="mailto:eirik.lygre@evita.no">Eirik Lygre</a>
211 */
212 class DailyFileAppenderCalendar extends java.util.GregorianCalendar
213 {
214 /**
215 Returns the current time in Millis
216 */
217 public long getTimeInMillis() {
218 return super.getTimeInMillis();
219 }
220
221 /**
222 Roll the date to the next hour, with minute, second and millisecond
223 set to zero.
224 */
225 public void rollToNextDay () {
226 this.add(java.util.Calendar.DATE, 0);
227 this.add(java.util.Calendar.HOUR, 0);
228 this.set(java.util.Calendar.MINUTE, 0);
229 this.set(java.util.Calendar.SECOND, 0);
230 this.set(java.util.Calendar.MILLISECOND, 0);
231 }
232 }