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DailyFileAppender1.javaAPI DocApache log4j 1.2.157423Sat Aug 25 00:09:34 BST 2007org.apache.log4j

DailyFileAppender

public class DailyFileAppender extends FileAppender
DailyFileAppender extends FileAppender to use filenames formatted with date/time information. The filename is recomputed every day at midnight. Note that the filename doesn't have to change every day, making it possible to have logfiles which are per-week or per-month. The appender computes the proper filename using the formats specified in java.text.SimpleDateFormat. The format requires that most static text is enclosed in single quotes, which are removed. The examples below show how quotes are used to embed static information in the format. Sample filenames: Filename pattern Filename "'/logs/trace-'yyyy-MM-dd'.log'" /logs/trace-2000-12-31.log "'/logs/trace-'yyyy-ww'.log'" /logs/trace-2000-52.log
author
Eirik Lygre

Fields Summary
public static final String
FILE_NAME_PATTERN_OPTION
A string constant used in naming the option for setting the filename pattern. Current value of this string constant is FileNamePattern.
private String
fileNamePattern
The filename pattern
private String
currentFileName
The actual formatted filename that is currently being written to
private long
nextFilenameComputingMillis
The timestamp when we shall next recompute the filename
Constructors Summary
public DailyFileAppender()
The default constructor does no longer set a default layout nor a default output target.
public DailyFileAppender(Layout layout, String filename, boolean append)
Instantiate a RollingFileAppender and open the file designated by filename. The opened filename will become the ouput destination for this appender.

If the append parameter is true, the file will be appended to. Otherwise, the file desginated by filename will be truncated before being opened.

    super(layout, filename, append);
public DailyFileAppender(Layout layout, String filename)
Instantiate a FileAppender and open the file designated by filename. The opened filename will become the output destination for this appender.

The file will be appended to.

    super(layout, filename);
Methods Summary
public voidactivateOptions()
If the a value for {@link #FILE_OPTION} is non-null, then {@link #setFile} is called with the values of {@link #FILE_OPTION} and {@link #APPEND_OPTION}.

since
0.8.1

    try {
	   setFile(null, super.fileAppend);
    }
    catch(java.io.IOException e) {
	   errorHandler.error("setFile(null,"+fileAppend+") call failed.",
		  	   e, ErrorCode.FILE_OPEN_FAILURE);
    }
public java.lang.String[]getOptionStrings()
Retuns the option names for this component, namely {@link #FILE_NAME_PATTERN_OPTION} in addition to the options of {@link FileAppender#getOptionStrings FileAppender}.


    return OptionConverter.concatanateArrays(super.getOptionStrings(),
		 new String[] {FILE_NAME_PATTERN_OPTION});
public synchronized voidsetFile(java.lang.String fileName, boolean append)
Set the current output file. The function will compute a new filename, and open a new file only when the name has changed. The function is automatically called once a day, to allow for daily files -- the purpose of this class.


    /* Compute filename, but only if fileNamePattern is specified */
    if (fileNamePattern == null) {
      errorHandler.error("Missing file pattern (" + FILE_NAME_PATTERN_OPTION + ") in setFile().");
      return;
    }

    Date now = new Date();

    fileName = new SimpleDateFormat(fileNamePattern).format (now);
    if (fileName.equals(currentFileName))
      return;

    /* Set up next filename checkpoint */
    DailyFileAppenderCalendar c = new DailyFileAppenderCalendar();
    c.rollToNextDay ();
    nextFilenameComputingMillis = c.getTimeInMillis ();

    currentFileName = fileName;

    super.setFile(fileName, append);
public voidsetOption(java.lang.String key, java.lang.String value)
Set the options for the appender

    super.setOption(key, value);    
    if(key.equalsIgnoreCase(FILE_NAME_PATTERN_OPTION)) {
      fileNamePattern = value;
    }
protected voidsubAppend(org.apache.log4j.spi.LoggingEvent event)
This method differentiates RollingFileAppender from its super class.

     
     if (System.currentTimeMillis () >= nextFilenameComputingMillis) {
      try {
        setFile (super.fileName, super.fileAppend);
      }
      catch(IOException e) {
        System.err.println("setFile(null, false) call failed.");
        e.printStackTrace();
      }
    }

    super.subAppend(event);