log4j扩展后的Appender

  1 import java.io.File;
  2 import java.io.IOException;
  3 import java.text.SimpleDateFormat;
  4 import java.util.ArrayList;
  5 import java.util.Calendar;
  6 import java.util.Date;
  7 import java.util.List;
  8 
  9 import org.apache.log4j.FileAppender;
 10 import org.apache.log4j.Layout;
 11 import org.apache.log4j.helpers.LogLog;
 12 import org.apache.log4j.spi.LoggingEvent;
 13 
 14 
 15 /**
 16 * this is an extend class of appender, which is suitable for the specified
 17 * datePattern--"yyyy-MM-dd" and the maxBackupIdex is not configurable.
 18 * 
 19 */
 20 public class DayRollingFileAppender extends FileAppender {
 21 
 22 /** datepattern was fixed as yyyy-MM-dd */
 23 private final String datePattern = "'.'yyyy-MM-dd";
 24 
 25 /** the default max count of log files */
 26 private int maxBackupIndex = 10;
 27 
 28 /** file name + date of last time */
 29 private String scheduledFilename;
 30 
 31 /**
 32          * The next time we estimate a rollover should occur.
 33          */
 34 private long nextCheck = System.currentTimeMillis() - 1;
 35 
 36 Date now = new Date();
 37 
 38 SimpleDateFormat sdf;
 39 
 40 /**
 41          * The default constructor does nothing.
 42          */
 43 public DayRollingFileAppender() {
 44 }
 45 
 46 public DayRollingFileAppender(Layout layout, String filename,
 47 int maxBackupIndex) throws IOException {
 48 super(layout, filename, true);
 49 this.maxBackupIndex = maxBackupIndex;
 50 activateOptions();
 51 }
 52 
 53 /**
 54          * used for inital the appender
 55          */
 56 public void activateOptions() {
 57 super.activateOptions();
 58 if (fileName != null) { // perf.log
 59 now.setTime(System.currentTimeMillis());
 60 sdf = new SimpleDateFormat(datePattern);
 61 File file = new File(fileName);
 62 // include the latest time as the file name
 63 scheduledFilename = fileName
 64 + sdf.format(new Date(file.lastModified()));
 65 } else {
 66 LogLog.error("File is not set for appender [" + name + "].");
 67 }
 68 if (maxBackupIndex <= 0) {
 69 LogLog
 70 .error("maxBackupIndex reset to default value[2],orignal value is:"
 71 + maxBackupIndex);
 72 maxBackupIndex = 10;
 73 }
 74 }
 75 
 76 /**
 77          * to update, if necessary, rename the file including the current date and
 78          * according to the maxBackupIndex, delete the expired file.
 79          * 
 80          */
 81 void rollOver() throws IOException {
 82 
 83 String datedFilename = fileName + sdf.format(now);
 84 // there is no need to update the file if the current date is the same
 85 // as last time
 86 if (scheduledFilename.equals(datedFilename)) {
 87 return;
 88 }
 89 
 90 // close current file, and rename it to datedFilename
 91 this.closeFile();
 92 
 93 File target = new File(scheduledFilename);
 94 if (target.exists()) {
 95 target.delete();
 96 }
 97 
 98 File file = new File(fileName);
 99 boolean result = file.renameTo(target);
100 if (result) {
101 LogLog.debug(fileName + " -> " + scheduledFilename);
102 } else {
103 LogLog.error("Failed to rename [" + fileName + "] to ["
104 + scheduledFilename + "].");
105 }
106 
107 // delete the expired log files according to the maxBackupIndex
108 if (maxBackupIndex > 0) {
109 File folder = new File(file.getParent());
110 List<String> maxBackupIndexDates = getMaxBackupIndexDates();
111 // go through the folder and delete the files which are not in the
112 // permitted dates.
113 for (File ff : folder.listFiles()) {
114 if (ff.getName().startsWith(file.getName())
115 && !ff.getName().equals(file.getName())) {
116 // get the date string from the file name
117 String markedDate = ff.getName().substring(
118 file.getName().length());
119 if (!maxBackupIndexDates.contains(markedDate)) {
120 result = ff.delete();
121 }
122 if (result) {
123 LogLog.debug(ff.getName() + " ->deleted ");
124 } else {
125 LogLog
126 .error("Failed to deleted old DayRollingFileAppender file :"
127 + ff.getName());
128 }
129 }
130 }
131 }
132 
133 try {
134 // This will also close the file. This is OK since multiple
135 // close operations are safe.
136 this.setFile(fileName, false, this.bufferedIO, this.bufferSize);
137 } catch (IOException e) {
138 errorHandler.error("setFile(" + fileName + ", false) call failed.");
139 }
140 
141 // update the date of the file
142 scheduledFilename = datedFilename;
143 }
144 
145 /**
146          * Actual writing occurs here.
147          * */
148 protected void subAppend(LoggingEvent event) {
149 long n = System.currentTimeMillis();
150 
151 // roll over when a new day comes, the first time will roll over
152 if (n >= nextCheck) {
153 now.setTime(n);
154 nextCheck = getNextDayCheckPoint(now);
155 try {
156 rollOver();
157 } catch (IOException ioe) {
158 LogLog.error("rollOver() failed.", ioe);
159 }
160 }
161 super.subAppend(event);
162 }
163 
164 /**
165          * get the exchange point of next day
166          * 
167          * @param now
168          * @return
169          */
170 long getNextDayCheckPoint(Date now) {
171 Calendar calendar = Calendar.getInstance();
172 calendar.setTime(now);
173 calendar.set(Calendar.HOUR_OF_DAY, 0);
174 calendar.set(Calendar.MINUTE, 0);
175 calendar.set(Calendar.SECOND, 0);
176 calendar.set(Calendar.MILLISECOND, 0);
177 calendar.add(Calendar.DATE, 1);
178 return calendar.getTimeInMillis();
179 }
180 
181 /** 
182    * get the scope of the log file date according to the count of log files which need to be backup
183    * 
184    * @return list<'fileName+yyyy-MM-dd'> 
185    */
186 List<String> getMaxBackupIndexDates() {
187 List<String> result = new ArrayList<String>();
188 if (maxBackupIndex > 0) {
189 for (int i = 1; i <= maxBackupIndex; i++) {
190 Calendar calendar = Calendar.getInstance();
191 calendar.setTime(now);
192 calendar.set(Calendar.HOUR_OF_DAY, 0);
193 calendar.set(Calendar.MINUTE, 0);
194 calendar.set(Calendar.SECOND, 0);
195 calendar.set(Calendar.MILLISECOND, 0);
196 calendar.add(Calendar.DATE, -i);
197 result.add(sdf.format(calendar.getTime()));
198 }
199 }
200 return result;
201 }
202 
203 public int getMaxBackupIndex() {
204 return maxBackupIndex;
205 }
206 
207 public void setMaxBackupIndex(int maxBackupIndex) {
208 this.maxBackupIndex = maxBackupIndex;
209 }
210 
211 public String getDatePattern() {
212 return datePattern;
213 }
214 
215 // public static void main(String[] args) {
216 // DOMConfigurator.configure(xxx.xml);
217 // Logger log = Logger.getLogger("A.log");
218 // log.info("test");
219 // }
220 }

1 DayRollingFileAppender should be the one defined by your own
2 log file should be the full path

3 remove the date pattern