/* * Copyright 1999-2005 The Apache Software Foundation. *  * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at *  *      http://www.apache.org/licenses/LICENSE-2.0 *  * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.log4j;import java.io.IOException;import java.io.Writer;import java.io.File;import org.apache.log4j.helpers.OptionConverter;import org.apache.log4j.helpers.LogLog;import org.apache.log4j.helpers.CountingQuietWriter;import org.apache.log4j.spi.LoggingEvent;/**   RollingFileAppender extends FileAppender to backup the log files when   they reach a certain size.   @author Heinz Richter   @author Ceki G&uuml;lc&uuml;*/public class RollingFileAppender extends FileAppender {  /**     The default maximum file size is 10MB.  */  protected long maxFileSize = 10*1024*1024;  /**     There is one backup file by default.   */  protected int  maxBackupIndex  = 1;  /**     The default constructor simply calls its {@link     FileAppender#FileAppender parents constructor}.  */  public  RollingFileAppender() {    super();  }  /**    Instantiate a RollingFileAppender and open the file designated by    <code>filename</code>. The opened filename will become the ouput    destination for this appender.    <p>If the <code>append</code> parameter is true, the file will be    appended to. Otherwise, the file desginated by    <code>filename</code> will be truncated before being opened.  */  public  RollingFileAppender(Layout layout, String filename, boolean append)                                      throws IOException {    super(layout, filename, append);  }  /**     Instantiate a FileAppender and open the file designated by    <code>filename</code>. The opened filename will become the output    destination for this appender.    <p>The file will be appended to.  */  public  RollingFileAppender(Layout layout, String filename) throws IOException {    super(layout, filename);  }  /**     Returns the value of the <b>MaxBackupIndex</b> option.   */  public  int getMaxBackupIndex() {    return maxBackupIndex;  } /**    Get the maximum size that the output file is allowed to reach    before being rolled over to backup files.    @since 1.1 */  public  long getMaximumFileSize() {    return maxFileSize;  }  /**     Implements the usual roll over behaviour.     <p>If <code>MaxBackupIndex</code> is positive, then files     {<code>File.1</code>, ..., <code>File.MaxBackupIndex -1</code>}     are renamed to {<code>File.2</code>, ...,     <code>File.MaxBackupIndex</code>}. Moreover, <code>File</code> is     renamed <code>File.1</code> and closed. A new <code>File</code> is     created to receive further log output.     <p>If <code>MaxBackupIndex</code> is equal to zero, then the     <code>File</code> is truncated with no backup files created.   */  public // synchronization not necessary since doAppend is alreasy synched  void rollOver() {    File target;    File file;    if (qw != null) {    	LogLog.debug("rolling over count=" + ((CountingQuietWriter) qw).getCount());    }    LogLog.debug("maxBackupIndex="+maxBackupIndex);    // If maxBackups <= 0, then there is no file renaming to be done.    if(maxBackupIndex > 0) {      // Delete the oldest file, to keep Windows happy.      file = new File(fileName + '.' + maxBackupIndex);      if (file.exists())       file.delete();      // Map {(maxBackupIndex - 1), ..., 2, 1} to {maxBackupIndex, ..., 3, 2}      for (int i = maxBackupIndex - 1; i >= 1; i--) {	file = new File(fileName + "." + i);	if (file.exists()) {	  target = new File(fileName + '.' + (i + 1));	  LogLog.debug("Renaming file " + file + " to " + target);	  file.renameTo(target);	}      }      // Rename fileName to fileName.1      target = new File(fileName + "." + 1);      this.closeFile(); // keep windows happy.      file = new File(fileName);      LogLog.debug("Renaming file " + file + " to " + target);      file.renameTo(target);    }    try {      // This will also close the file. This is OK since multiple      // close operations are safe.      this.setFile(fileName, false, bufferedIO, bufferSize);    }    catch(IOException e) {      LogLog.error("setFile("+fileName+", false) call failed.", e);    }  }  public  synchronized  void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)                                                                 throws IOException {    super.setFile(fileName, append, this.bufferedIO, this.bufferSize);    if(append) {      File f = new File(fileName);      ((CountingQuietWriter) qw).setCount(f.length());    }  }  /**     Set the maximum number of backup files to keep around.     <p>The <b>MaxBackupIndex</b> option determines how many backup     files are kept before the oldest is erased. This option takes     a positive integer value. If set to zero, then there will be no     backup files and the log file will be truncated when it reaches     <code>MaxFileSize</code>.   */  public  void setMaxBackupIndex(int maxBackups) {    this.maxBackupIndex = maxBackups;  }  /**     Set the maximum size that the output file is allowed to reach     before being rolled over to backup files.     <p>This method is equivalent to {@link #setMaxFileSize} except     that it is required for differentiating the setter taking a     <code>long</code> argument from the setter taking a     <code>String</code> argument by the JavaBeans {@link     java.beans.Introspector Introspector}.     @see #setMaxFileSize(String) */  public  void setMaximumFileSize(long maxFileSize) {    this.maxFileSize = maxFileSize;  }  /**     Set the maximum size that the output file is allowed to reach     before being rolled over to backup files.     <p>In configuration files, the <b>MaxFileSize</b> option takes an     long integer in the range 0 - 2^63. You can specify the value     with the suffixes "KB", "MB" or "GB" so that the integer is     interpreted being expressed respectively in kilobytes, megabytes     or gigabytes. For example, the value "10KB" will be interpreted     as 10240.   */  public  void setMaxFileSize(String value) {    maxFileSize = OptionConverter.toFileSize(value, maxFileSize + 1);  }  protected  void setQWForFiles(Writer writer) {     this.qw = new CountingQuietWriter(writer, errorHandler);  }  /**     This method differentiates RollingFileAppender from its super     class.     @since 0.9.0  */  protected  void subAppend(LoggingEvent event) {    super.subAppend(event);    if((fileName != null) &&                     ((CountingQuietWriter) qw).getCount() >= maxFileSize)      this.rollOver();   }}