Package org.apache.logging.log4j.core.util.datetime

Class FastDatePrinter

java.lang.Object
org.apache.logging.log4j.core.util.datetime.FastDatePrinter
All Implemented Interfaces:
Serializable, DatePrinter
public class FastDatePrinter extends Object implements DatePrinter, Serializable

FastDatePrinter is a fast and thread-safe version of SimpleDateFormat.

To obtain a FastDatePrinter, use FastDateFormat.getInstance(String, TimeZone, Locale) or another variation of the factory methods of FastDateFormat.

Since FastDatePrinter is thread safe, you can use a static member instance:

private static final DatePrinter DATE_PRINTER = FastDateFormat.getInstance("yyyy-MM-dd");

This class can be used as a direct replacement to SimpleDateFormat in most formatting situations. This class is especially useful in multi-threaded server environments. SimpleDateFormat is not thread-safe in any JDK version, nor will it be as Sun have closed the bug/RFE.

Only formatting is supported by this class, but all patterns are compatible with SimpleDateFormat (except time zones and some year patterns - see below).

Java 1.4 introduced a new pattern letter, 'Z', to represent time zones in RFC822 format (eg. +0800 or -1100). This pattern letter can be used here (on all JDK versions).

In addition, the pattern 'ZZ' has been made to represent ISO 8601 extended format time zones (eg. +08:00 or -11:00). This introduces a minor incompatibility with Java 1.4, but at a gain of useful functionality.

Starting with JDK7, ISO 8601 support was added using the pattern 'X'. To maintain compatibility, 'ZZ' will continue to be supported, but using one of the 'X' formats is recommended.

Javadoc cites for the year pattern: For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted as a number. Starting with Java 1.7 a pattern of 'Y' or 'YYY' will be formatted as '2003', while it was '03' in former Java versions. FastDatePrinter implements the behavior of Java 7.

Copied and modified from Apache Commons Lang.

Since:
Apache Commons Lang 3.2
See Also:

  • Field Details

    • FULL

      public static final int FULL
      FULL locale dependent date or time style.
      See Also:

    • LONG

      public static final int LONG
      LONG locale dependent date or time style.
      See Also:

    • MEDIUM

      public static final int MEDIUM
      MEDIUM locale dependent date or time style.
      See Also:

    • SHORT

      public static final int SHORT
      SHORT locale dependent date or time style.
      See Also:

  • Constructor Details

  • Method Details

    • parsePattern

      protected List<org.apache.logging.log4j.core.util.datetime.FastDatePrinter.Rule> parsePattern()

      Returns a list of Rules given a pattern.

      Returns:
      a List of Rule objects
      Throws:
      IllegalArgumentException - if pattern is invalid

    • parseToken

      protected String parseToken(String pattern, int[] indexRef)

      Performs the parsing of tokens.

      Parameters:
      pattern - the pattern
      indexRef - index references
      Returns:
      parsed token

    • selectNumberRule

      protected org.apache.logging.log4j.core.util.datetime.FastDatePrinter.NumberRule selectNumberRule(int field, int padding)

      Gets an appropriate rule for the padding required.

      Parameters:
      field - the field to get a rule for
      padding - the padding required
      Returns:
      a new rule with the correct padding

    • format

      @Deprecated public StringBuilder format(Object obj, StringBuilder toAppendTo, FieldPosition pos)
      Deprecated.
      Use {format(Date), {format(Calendar), {format(long), or {format(Object)

      Formats a Date, Calendar or Long (milliseconds) object.

      Specified by:
      format in interface DatePrinter
      Parameters:
      obj - the object to format
      toAppendTo - the buffer to append to
      pos - the position - ignored
      Returns:
      the buffer passed in
      See Also:

    • format

      public String format(long millis)
      Description copied from interface: DatePrinter

      Formats a millisecond long value.

      Specified by:
      format in interface DatePrinter
      Parameters:
      millis - the millisecond value to format
      Returns:
      the formatted string

    • format

      public String format(Date date)
      Description copied from interface: DatePrinter

      Formats a Date object using a GregorianCalendar.

      Specified by:
      format in interface DatePrinter
      Parameters:
      date - the date to format
      Returns:
      the formatted string

    • format

      public String format(Calendar calendar)
      Description copied from interface: DatePrinter

      Formats a Calendar object.

      The TimeZone set on the Calendar is only used to adjust the time offset. The TimeZone specified during the construction of the Parser will determine the TimeZone used in the formatted string.
      Specified by:
      format in interface DatePrinter
      Parameters:
      calendar - the calendar to format.
      Returns:
      the formatted string

    • format

      public <B extends Appendable> B format(long millis, B buf)
      Description copied from interface: DatePrinter

      Formats a millisecond long value into the supplied Appendable.

      Specified by:
      format in interface DatePrinter
      Type Parameters:
      B - the Appendable class type, usually StringBuilder or StringBuffer.
      Parameters:
      millis - the millisecond value to format
      buf - the buffer to format into
      Returns:
      the specified string buffer

    • format

      public <B extends Appendable> B format(Date date, B buf)
      Description copied from interface: DatePrinter

      Formats a Date object into the supplied Appendable using a GregorianCalendar.

      Specified by:
      format in interface DatePrinter
      Type Parameters:
      B - the Appendable class type, usually StringBuilder or StringBuffer.
      Parameters:
      date - the date to format
      buf - the buffer to format into
      Returns:
      the specified string buffer

    • format

      public <B extends Appendable> B format(Calendar calendar, B buf)
      Description copied from interface: DatePrinter

      Formats a Calendar object into the supplied Appendable.

      The TimeZone set on the Calendar is only used to adjust the time offset. The TimeZone specified during the construction of the Parser will determine the TimeZone used in the formatted string.
      Specified by:
      format in interface DatePrinter
      Type Parameters:
      B - the Appendable class type, usually StringBuilder or StringBuffer.
      Parameters:
      calendar - the calendar to format
      buf - the buffer to format into
      Returns:
      the specified string buffer

    • applyRules

      @Deprecated protected StringBuffer applyRules(Calendar calendar, StringBuffer buf)
      Deprecated.
      use format(Calendar) or format(Calendar, Appendable)
      Performs the formatting by applying the rules to the specified calendar.
      Parameters:
      calendar - the calendar to format
      buf - the buffer to format into
      Returns:
      the specified string buffer

    • getPattern

      public String getPattern()
      Description copied from interface: DatePrinter

      Gets the pattern used by this printer.

      Specified by:
      getPattern in interface DatePrinter
      Returns:
      the pattern, SimpleDateFormat compatible

    • getTimeZone

      public TimeZone getTimeZone()
      Description copied from interface: DatePrinter

      Gets the time zone used by this printer.

      This zone is always used for Date printing.

      Specified by:
      getTimeZone in interface DatePrinter
      Returns:
      the time zone

    • getLocale

      public Locale getLocale()
      Description copied from interface: DatePrinter

      Gets the locale used by this printer.

      Specified by:
      getLocale in interface DatePrinter
      Returns:
      the locale

    • getMaxLengthEstimate

      public int getMaxLengthEstimate()

      Gets an estimate for the maximum string length that the formatter will produce.

      The actual formatted length will almost always be less than or equal to this amount.

      Returns:
      the maximum formatted length

    • equals

      public boolean equals(Object obj)

      Compares two objects for equality.

      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare to
      Returns:
      true if equal

    • hashCode

      public int hashCode()

      Returns a hash code compatible with equals.

      Overrides:
      hashCode in class Object
      Returns:
      a hash code compatible with equals

    • toString

      public String toString()

      Gets a debugging string version of this formatter.

      Overrides:
      toString in class Object
      Returns:
      a debugging string