myrollingfileappender.java

自己写的数据库连接池

/*
 * 创建日期 2005-9-15
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
package cn.com.infosec.IDCard.common.util.logger;

import java.io.IOException;
import java.io.Writer;
import java.io.File;

import org.apache.log4j.Layout;
import org.apache.log4j.helpers.OptionConverter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.spi.LoggingEvent;
/**
 * @author hyoffice
 *
 * TODO 要更改此生成的类型注释的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
public class MyRollingFileAppender extends MyFileAppender {
	/**
    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
 MyRollingFileAppender() {
   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
 MyRollingFileAppender(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
 MyRollingFileAppender(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;

   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();
  }
}