Class DateTime


  • public class DateTime
    extends java.lang.Object
    High performance converters from date/time byte encodings to JDBC Date, Time and Timestamp objects.

    Using this class for direct date/time conversions from bytes offers superior performance over the alternative method of first constructing a Java String from the encoded bytes, and then using java.sql.Date.valueOf(), java.sql.Time.valueOf() or java.sql.Timestamp.valueOf().

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private DateTime()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      (package private) static java.sql.Date dateBytesToDate​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      Expected character representation is DERBY string representation of a date, which is in JIS format: yyyy-mm-dd
      (package private) static java.sql.Timestamp dateBytesToTimestamp​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      Expected character representation is DERBY string representation of a date which is in JIS format: yyyy-mm-dd
      static int dateToDateBytes​(byte[] buffer, int offset, DateTimeValue date)
      Date is converted to a char representation in JDBC date format: yyyy-mm-dd date format and then converted to bytes using UTF8 encoding
      private static java.util.Calendar getCleanCalendar​(java.util.Calendar recyclableCal)
      Return a clean (i.e. all values cleared out) Calendar object that can be used for creating Time, Timestamp, and Date objects.
      static int getTimestampLength​(boolean supportsTimestampNanoseconds)
      Return the length of a timestamp depending on whether timestamps should have full nanosecond precision or be truncated to just microseconds.
      private static int parseTimestampString​(java.lang.String timestamp, java.util.Calendar cal, boolean supportsTimestampNanoseconds)
      Parse a String of the form yyyy-mm-dd-hh.mm.ss.ffffff[fff] and store the various fields into the received Calendar object.
      (package private) static java.sql.Time timeBytesToTime​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      Expected character representation is DERBY string representation of time, which is in the format: hh.mm.ss
      (package private) static java.sql.Timestamp timeBytesToTimestamp​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      Expected character representation is DERBY string representation of time which is in the format: hh.mm.ss
      (package private) static java.sql.Date timestampBytesToDate​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      See getTimestampLength() for an explanation of how timestamps are formatted.
      (package private) static java.sql.Time timestampBytesToTime​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding)
      See getTimestampLength() for an explanation of how timestamps are formatted.
      (package private) static java.sql.Timestamp timestampBytesToTimestamp​(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.nio.charset.Charset encoding, boolean supportsTimestampNanoseconds)
      See getTimestampLength() for an explanation of how timestamps are formatted.
      static int timestampToTimestampBytes​(byte[] buffer, int offset, DateTimeValue timestamp, boolean supportsTimestampNanoseconds)
      See getTimestampLength() for an explanation of how timestamps are formatted.
      static int timeToTimeBytes​(byte[] buffer, int offset, DateTimeValue time)
      java.sql.Time is converted to character representation which is in JDBC time escape format: hh:mm:ss, which is the same as JIS time format in DERBY string representation of a time.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • dateRepresentationLength

        private static final int dateRepresentationLength
        See Also:
        Constant Field Values
      • timeRepresentationLength

        private static final int timeRepresentationLength
        See Also:
        Constant Field Values
      • timestampRepresentationLength

        private static final int timestampRepresentationLength
        See Also:
        Constant Field Values
    • Constructor Detail

      • DateTime

        private DateTime()
    • Method Detail

      • dateBytesToDate

        static final java.sql.Date dateBytesToDate​(byte[] buffer,
                                                   int offset,
                                                   java.util.Calendar recyclableCal,
                                                   java.nio.charset.Charset encoding)
        Expected character representation is DERBY string representation of a date, which is in JIS format: yyyy-mm-dd
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer data
        Returns:
        Date translated from buffer with specified encoding
      • timeBytesToTime

        static final java.sql.Time timeBytesToTime​(byte[] buffer,
                                                   int offset,
                                                   java.util.Calendar recyclableCal,
                                                   java.nio.charset.Charset encoding)
        Expected character representation is DERBY string representation of time, which is in the format: hh.mm.ss
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        Returns:
        Time translated from buffer with specified encoding
      • timestampBytesToTimestamp

        static final java.sql.Timestamp timestampBytesToTimestamp​(byte[] buffer,
                                                                  int offset,
                                                                  java.util.Calendar recyclableCal,
                                                                  java.nio.charset.Charset encoding,
                                                                  boolean supportsTimestampNanoseconds)
        See getTimestampLength() for an explanation of how timestamps are formatted.
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        supportsTimestampNanoseconds - true if the server supports nanoseconds in timestamps
        Returns:
        TimeStamp translated from buffer with specified encoding
      • parseTimestampString

        private static int parseTimestampString​(java.lang.String timestamp,
                                                java.util.Calendar cal,
                                                boolean supportsTimestampNanoseconds)
        Parse a String of the form yyyy-mm-dd-hh.mm.ss.ffffff[fff] and store the various fields into the received Calendar object.
        Parameters:
        timestamp - Timestamp value to parse, as a String.
        cal - Calendar into which to store the parsed fields. Should not be null.
        supportsTimestampNanoseconds - true if the server supports nanoseconds in timestamps
        Returns:
        The nanoseconds field as parsed from the timestamp string. This cannot be set in the Calendar object but we still want to preserve the value, in case the caller needs it (for example, to create a java.sql.Timestamp with nanosecond precision).
      • dateToDateBytes

        public static final int dateToDateBytes​(byte[] buffer,
                                                int offset,
                                                DateTimeValue date)
                                         throws SqlException
        Date is converted to a char representation in JDBC date format: yyyy-mm-dd date format and then converted to bytes using UTF8 encoding
        Parameters:
        buffer - bytes in UTF8 encoding of the date
        offset - write into the buffer from this offset
        date - date value
        Returns:
        DateTime.dateRepresentationLength. This is the fixed length in bytes taken to represent the date value
        Throws:
        SqlException
      • timeToTimeBytes

        public static final int timeToTimeBytes​(byte[] buffer,
                                                int offset,
                                                DateTimeValue time)
        java.sql.Time is converted to character representation which is in JDBC time escape format: hh:mm:ss, which is the same as JIS time format in DERBY string representation of a time. The char representation is converted to bytes using UTF8 encoding.
        Parameters:
        buffer - bytes in UTF8 encoding of the time
        offset - write into the buffer from this offset
        time - java.sql.Time value
        Returns:
        DateTime.timeRepresentationLength. This is the fixed length in bytes taken to represent the time value
      • timestampToTimestampBytes

        public static final int timestampToTimestampBytes​(byte[] buffer,
                                                          int offset,
                                                          DateTimeValue timestamp,
                                                          boolean supportsTimestampNanoseconds)
                                                   throws SqlException
        See getTimestampLength() for an explanation of how timestamps are formatted.
        Parameters:
        buffer - bytes in UTF8 encoding of the timestamp
        offset - write into the buffer from this offset
        timestamp - timestamp value
        supportsTimestampNanoseconds - true if the server supports nanoseconds in timestamps
        Returns:
        DateTime.timestampRepresentationLength. This is the fixed length in bytes, taken to represent the timestamp value
        Throws:
        SqlException
      • dateBytesToTimestamp

        static final java.sql.Timestamp dateBytesToTimestamp​(byte[] buffer,
                                                             int offset,
                                                             java.util.Calendar recyclableCal,
                                                             java.nio.charset.Charset encoding)
        Expected character representation is DERBY string representation of a date which is in JIS format: yyyy-mm-dd
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        Returns:
        Timestamp translated from buffer with specified encoding
      • timeBytesToTimestamp

        static final java.sql.Timestamp timeBytesToTimestamp​(byte[] buffer,
                                                             int offset,
                                                             java.util.Calendar recyclableCal,
                                                             java.nio.charset.Charset encoding)
        Expected character representation is DERBY string representation of time which is in the format: hh.mm.ss
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        Returns:
        Timestamp translated from buffer with specified encoding
      • timestampBytesToDate

        static final java.sql.Date timestampBytesToDate​(byte[] buffer,
                                                        int offset,
                                                        java.util.Calendar recyclableCal,
                                                        java.nio.charset.Charset encoding)
        See getTimestampLength() for an explanation of how timestamps are formatted.
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        Returns:
        Date translated from buffer with specified encoding
      • timestampBytesToTime

        static final java.sql.Time timestampBytesToTime​(byte[] buffer,
                                                        int offset,
                                                        java.util.Calendar recyclableCal,
                                                        java.nio.charset.Charset encoding)
        See getTimestampLength() for an explanation of how timestamps are formatted.
        Parameters:
        buffer -
        offset -
        recyclableCal -
        encoding - encoding of buffer
        Returns:
        Time translated from buffer with specified Encoding
      • getCleanCalendar

        private static java.util.Calendar getCleanCalendar​(java.util.Calendar recyclableCal)
        Return a clean (i.e. all values cleared out) Calendar object that can be used for creating Time, Timestamp, and Date objects. If the received Calendar object is non-null, then just clear that and return it.
        Parameters:
        recyclableCal - Calendar object to use if non-null.
      • getTimestampLength

        public static int getTimestampLength​(boolean supportsTimestampNanoseconds)
        Return the length of a timestamp depending on whether timestamps should have full nanosecond precision or be truncated to just microseconds. java.sql.Timestamp is converted to a character representation which is a DERBY string representation of a timestamp converted to bytes using UTF8 encoding. For Derby 10.6 and above, this is yyyy-mm-dd-hh.mm.ss.fffffffff. For Derby 10.5 and below, this is yyyy-mm-dd-hh.mm.ss.ffffff. See DERBY-2602. and then converted to bytes using UTF8 encoding
        Parameters:
        supportsTimestampNanoseconds - true if the connection supports nanoseconds in timestamps