org.apache.derby.client.am

Class DateTime

java.lang.Object

org.apache.derby.client.am.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().

Field Summary

Fields

Modifier and Type	Field and Description
private static int	dateRepresentationLength
private static int	timeRepresentationLength
private static int	timestampRepresentationLength

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DateTime()

Method Summary

Modifier and Type	Method and Description
static java.sql.Date	dateBytesToDate(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String encoding) Expected character representation is DERBY string representation of a date, which is in JIS format: yyyy-mm-dd
static java.sql.Timestamp	dateBytesToTimestamp(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String 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.
static java.sql.Time	timeBytesToTime(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String encoding) Expected character representation is DERBY string representation of time, which is in the format: hh.mm.ss
static java.sql.Timestamp	timeBytesToTimestamp(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String encoding) Expected character representation is DERBY string representation of time which is in the format: hh.mm.ss
static java.sql.Date	timestampBytesToDate(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String encoding) See getTimestampLength() for an explanation of how timestamps are formatted.
static java.sql.Time	timestampBytesToTime(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String encoding) See getTimestampLength() for an explanation of how timestamps are formatted.
static java.sql.Timestamp	timestampBytesToTimestamp(byte[] buffer, int offset, java.util.Calendar recyclableCal, java.lang.String 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

public static final java.sql.Date dateBytesToDate(byte[] buffer,
                                                  int offset,
                                                  java.util.Calendar recyclableCal,
                                                  java.lang.String encoding)
                                           throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timeBytesToTime

public static final java.sql.Time timeBytesToTime(byte[] buffer,
                                                  int offset,
                                                  java.util.Calendar recyclableCal,
                                                  java.lang.String encoding)
                                           throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timestampBytesToTimestamp

public static final java.sql.Timestamp timestampBytesToTimestamp(byte[] buffer,
                                                                 int offset,
                                                                 java.util.Calendar recyclableCal,
                                                                 java.lang.String encoding,
                                                                 boolean supportsTimestampNanoseconds)
                                                          throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

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,
                                        java.io.UnsupportedEncodingException

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

java.io.UnsupportedEncodingException - if UTF8 Encoding is not supported

timeToTimeBytes

public static final int timeToTimeBytes(byte[] buffer,
                                        int offset,
                                        DateTimeValue time)
                                 throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timestampToTimestampBytes

public static final int timestampToTimestampBytes(byte[] buffer,
                                                  int offset,
                                                  DateTimeValue timestamp,
                                                  boolean supportsTimestampNanoseconds)
                                           throws SqlException,
                                                  java.io.UnsupportedEncodingException

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

java.io.UnsupportedEncodingException

dateBytesToTimestamp

public static final java.sql.Timestamp dateBytesToTimestamp(byte[] buffer,
                                                            int offset,
                                                            java.util.Calendar recyclableCal,
                                                            java.lang.String encoding)
                                                     throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timeBytesToTimestamp

public static final java.sql.Timestamp timeBytesToTimestamp(byte[] buffer,
                                                            int offset,
                                                            java.util.Calendar recyclableCal,
                                                            java.lang.String encoding)
                                                     throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timestampBytesToDate

public static final java.sql.Date timestampBytesToDate(byte[] buffer,
                                                       int offset,
                                                       java.util.Calendar recyclableCal,
                                                       java.lang.String encoding)
                                                throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

timestampBytesToTime

public static final java.sql.Time timestampBytesToTime(byte[] buffer,
                                                       int offset,
                                                       java.util.Calendar recyclableCal,
                                                       java.lang.String encoding)
                                                throws java.io.UnsupportedEncodingException

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

Throws:

java.io.UnsupportedEncodingException

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