Class DateFormatCache

java.lang.Object
org.apache.juli.DateFormatCache
public class DateFormatCache extends Object

Cache structure for SimpleDateFormat formatted timestamps based on seconds.

Millisecond formatting using S is not supported. You should add the millisecond information after getting back the second formatting.

The cache consists of entries for a consecutive range of seconds. The length of the range is configurable. It is implemented based on a cyclic buffer. New entries shift the range.

The cache is not thread safe. It can be used without synchronization via thread local instances, or with synchronization as a global cache.

The cache can be created with a parent cache to build a cache hierarchy. Access to the parent cache is thread safe.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final char
    MSEC_PATTERN
    Pattern character used to replace 'S' (milliseconds) in format strings to make timestamps cacheable.

  • Constructor Summary

    Constructors
    Constructor
    Description
    DateFormatCache(int size, String format, DateFormatCache parent)
    Create a new DateFormatCache.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getFormat(long time)
    Get the formatted timestamp for the given time.
    String
    getTimeFormat()
    Get the time format string used by this cache.
    protected static String
    tidyFormat(String format)
    Replace the millisecond formatting character 'S' by some dummy characters in order to make the resulting formatted time stamps cacheable.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • MSEC_PATTERN

      public static final char MSEC_PATTERN
      Pattern character used to replace 'S' (milliseconds) in format strings to make timestamps cacheable.
      See Also:

  • Constructor Details

    • DateFormatCache

      public DateFormatCache(int size, String format, DateFormatCache parent)
      Create a new DateFormatCache.
      Parameters:
      size - The number of cached entries
      format - The timestamp format string
      parent - The parent cache for building a cache hierarchy

  • Method Details

    • tidyFormat

      protected static String tidyFormat(String format)
      Replace the millisecond formatting character 'S' by some dummy characters in order to make the resulting formatted time stamps cacheable. Our consumer might choose to replace the dummy chars with the actual milliseconds because that's relatively cheap.
      Parameters:
      format - the format
      Returns:
      the replacement format

    • getFormat

      public String getFormat(long time)
      Get the formatted timestamp for the given time.
      Parameters:
      time - The time in milliseconds
      Returns:
      the formatted timestamp string

    • getTimeFormat

      public String getTimeFormat()
      Get the time format string used by this cache.
      Returns:
      the time format string