DateTimeUtils (Calcite Avatica 1.2.0-incubating API)

java.lang.Object
- org.apache.calcite.avatica.util.DateTimeUtils

```
public class DateTimeUtils
extends Object
```
Utility functions for datetime types: date, time, timestamp.
Used by the JDBC driver.
TODO: review methods for performance. Due to allocations required, it may be preferable to introduce a "formatter" with the required state.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`DateTimeUtils.PrecisionTime` Helper class for `parsePrecisionDateTimeLiteral(java.lang.String, java.lang.String, java.util.TimeZone)`

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`DATE_FORMAT_STRING` The SimpleDateFormat string for ISO dates, "yyyy-MM-dd".
`static TimeZone`	`DEFAULT_ZONE` The Java default time zone.
`static int`	`EPOCH_JULIAN` The julian date of the epoch, 1970-01-01.
`static TimeZone`	`GMT_ZONE` The GMT time zone.
`static long`	`MILLIS_PER_DAY` The number of milliseconds in a day.
`static long`	`MILLIS_PER_HOUR` The number of milliseconds in an hour.
`static long`	`MILLIS_PER_MINUTE` The number of milliseconds in a minute.
`static long`	`MILLIS_PER_SECOND` The number of milliseconds in a second.
`static String`	`TIME_FORMAT_STRING` The SimpleDateFormat string for ISO times, "HH:mm:ss".
`static String`	`TIMESTAMP_FORMAT_STRING` The SimpleDateFormat string for ISO timestamps, "yyyy-MM-dd HH:mm:ss".
`static Calendar`	`ZERO_CALENDAR` Calendar set to the epoch (1970-01-01 00:00:00 UTC).

Method Summary

Methods
Modifier and Type	Method and Description
`static void`	`checkDateFormat(String pattern)` Checks if the date/time format is valid
`static int`	`dateStringToUnixDate(String s)`
`static int`	`digitCount(int v)`
`static TimeZone`	`getTimeZone(Calendar cal)` Gets the active time zone based on a Calendar argument
`static String`	`intervalDayTimeToString(long v, TimeUnitRange range, int scale)`
`static String`	`intervalYearMonthToString(int v, TimeUnitRange range)`
`static SimpleDateFormat`	`newDateFormat(String format)` Creates a new date formatter with Farrago specific options.
`static StringBuilder`	`number(StringBuilder buf, int v, int n)`
`static Calendar`	`parseDateFormat(String s, String pattern, TimeZone tz)` Parses a string using `SimpleDateFormat` and a given pattern.
`static DateTimeUtils.PrecisionTime`	`parsePrecisionDateTimeLiteral(String s, String pattern, TimeZone tz)` Parses a string using `SimpleDateFormat` and a given pattern, and if present, parses a fractional seconds component.
`static long`	`powerX(long a, long b)` Cheap, unsafe, long power.
`static long`	`timestampStringToUnixDate(String s)`
`static int`	`timeStringToUnixDate(String v)`
`static int`	`timeStringToUnixDate(String v, int start)`
`static long`	`unixDateCeil(TimeUnitRange range, long date)`
`static long`	`unixDateExtract(TimeUnitRange range, long date)`
`static long`	`unixDateFloor(TimeUnitRange range, long date)`
`static String`	`unixDateToString(int date)` Helper for CAST({date} AS VARCHAR(n)).
`static long`	`unixTimestamp(int year, int month, int day, int hour, int minute, int second)`
`static long`	`unixTimestampCeil(TimeUnitRange range, long timestamp)`
`static long`	`unixTimestampFloor(TimeUnitRange range, long timestamp)`
`static String`	`unixTimestampToString(long timestamp)` Helper for CAST({timestamp} AS VARCHAR(n)).
`static String`	`unixTimeToString(int time)` Helper for CAST({timestamp} AS VARCHAR(n)).
`static int`	`ymdToJulian(int year, int month, int day)`
`static int`	`ymdToUnixDate(int year, int month, int day)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EPOCH_JULIAN
```
public static final int EPOCH_JULIAN
```
    The julian date of the epoch, 1970-01-01.
    
    See Also:
    Constant Field Values
  - DATE_FORMAT_STRING
```
public static final String DATE_FORMAT_STRING
```
    The SimpleDateFormat string for ISO dates, "yyyy-MM-dd".
    
    See Also:
    Constant Field Values
  - TIME_FORMAT_STRING
```
public static final String TIME_FORMAT_STRING
```
    The SimpleDateFormat string for ISO times, "HH:mm:ss".
    
    See Also:
    Constant Field Values
  - TIMESTAMP_FORMAT_STRING
```
public static final String TIMESTAMP_FORMAT_STRING
```
    The SimpleDateFormat string for ISO timestamps, "yyyy-MM-dd HH:mm:ss".
    
    See Also:
    Constant Field Values
  - GMT_ZONE
```
public static final TimeZone GMT_ZONE
```
    The GMT time zone.
  - DEFAULT_ZONE
```
public static final TimeZone DEFAULT_ZONE
```
    The Java default time zone.
  - MILLIS_PER_SECOND
```
public static final long MILLIS_PER_SECOND
```
    The number of milliseconds in a second.
    
    See Also:
    Constant Field Values
  - MILLIS_PER_MINUTE
```
public static final long MILLIS_PER_MINUTE
```
    The number of milliseconds in a minute.
    
    See Also:
    Constant Field Values
  - MILLIS_PER_HOUR
```
public static final long MILLIS_PER_HOUR
```
    The number of milliseconds in an hour.
    
    See Also:
    Constant Field Values
  - MILLIS_PER_DAY
```
public static final long MILLIS_PER_DAY
```
    The number of milliseconds in a day.
    This is the modulo 'mask' used when converting TIMESTAMP values to DATE and TIME values.
    
    See Also:
    Constant Field Values
  - ZERO_CALENDAR
```
public static final Calendar ZERO_CALENDAR
```
    Calendar set to the epoch (1970-01-01 00:00:00 UTC). Useful for initializing other values. Calendars are not immutable, so be careful not to screw up this object for everyone else.
- Method Detail
  - parseDateFormat
```
public static Calendar parseDateFormat(String s,
                       String pattern,
                       TimeZone tz)
```
    Parses a string using SimpleDateFormat and a given pattern. The entire string must match the pattern specified.
    
    Parameters:
    s - string to be parsed
    pattern - SimpleDateFormat pattern
    tz - time zone in which to interpret string. Defaults to the Java default time zone
    
    Returns:
    a Calendar initialized with the parsed value, or null if parsing failed. If returned, the Calendar is configured to the GMT time zone.
  - parsePrecisionDateTimeLiteral
```
public static DateTimeUtils.PrecisionTime parsePrecisionDateTimeLiteral(String s,
                                                        String pattern,
                                                        TimeZone tz)
```
    Parses a string using SimpleDateFormat and a given pattern, and if present, parses a fractional seconds component. The fractional seconds component must begin with a decimal point ('.') followed by numeric digits. The precision is rounded to a maximum of 3 digits of fractional seconds precision (to obtain milliseconds).
    
    Parameters:
    s - string to be parsed
    pattern - SimpleDateFormat pattern
    tz - time zone in which to interpret string. Defaults to the local time zone
    
    Returns:
    a PrecisionTime initialized with the parsed value, or null if parsing failed. The PrecisionTime contains a GMT Calendar and a precision.
  - getTimeZone
```
public static TimeZone getTimeZone(Calendar cal)
```
    Gets the active time zone based on a Calendar argument
  - checkDateFormat
```
public static void checkDateFormat(String pattern)
```
    Checks if the date/time format is valid
    
    Parameters:
    pattern - SimpleDateFormat pattern
    
    Throws:
    
    IllegalArgumentException - if the given pattern is invalid
  - newDateFormat
```
public static SimpleDateFormat newDateFormat(String format)
```
    Creates a new date formatter with Farrago specific options. Farrago parsing is strict and does not allow values such as day 0, month 13, etc.
    
    Parameters:
    format - SimpleDateFormat pattern
  - unixTimestampToString
```
public static String unixTimestampToString(long timestamp)
```
    Helper for CAST({timestamp} AS VARCHAR(n)).
  - unixTimeToString
```
public static String unixTimeToString(int time)
```
    Helper for CAST({timestamp} AS VARCHAR(n)).
  - unixDateToString
```
public static String unixDateToString(int date)
```
    Helper for CAST({date} AS VARCHAR(n)).
  - intervalYearMonthToString
```
public static String intervalYearMonthToString(int v,
                               TimeUnitRange range)
```
  - number
```
public static StringBuilder number(StringBuilder buf,
                   int v,
                   int n)
```
  - digitCount
```
public static int digitCount(int v)
```
  - powerX
```
public static long powerX(long a,
          long b)
```
    Cheap, unsafe, long power. power(2, 3) returns 8.
  - intervalDayTimeToString
```
public static String intervalDayTimeToString(long v,
                             TimeUnitRange range,
                             int scale)
```
  - dateStringToUnixDate
```
public static int dateStringToUnixDate(String s)
```
  - timeStringToUnixDate
```
public static int timeStringToUnixDate(String v)
```
  - timeStringToUnixDate
```
public static int timeStringToUnixDate(String v,
                       int start)
```
  - timestampStringToUnixDate
```
public static long timestampStringToUnixDate(String s)
```
  - unixDateExtract
```
public static long unixDateExtract(TimeUnitRange range,
                   long date)
```
  - unixTimestampFloor
```
public static long unixTimestampFloor(TimeUnitRange range,
                      long timestamp)
```
  - unixDateFloor
```
public static long unixDateFloor(TimeUnitRange range,
                 long date)
```
  - unixTimestampCeil
```
public static long unixTimestampCeil(TimeUnitRange range,
                     long timestamp)
```
  - unixDateCeil
```
public static long unixDateCeil(TimeUnitRange range,
                long date)
```
  - ymdToUnixDate
```
public static int ymdToUnixDate(int year,
                int month,
                int day)
```
  - ymdToJulian
```
public static int ymdToJulian(int year,
              int month,
              int day)
```
  - unixTimestamp
```
public static long unixTimestamp(int year,
                 int month,
                 int day,
                 int hour,
                 int minute,
                 int second)
```

Class DateTimeUtils

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EPOCH_JULIAN

DATE_FORMAT_STRING

TIME_FORMAT_STRING

TIMESTAMP_FORMAT_STRING

GMT_ZONE

DEFAULT_ZONE

MILLIS_PER_SECOND

MILLIS_PER_MINUTE

MILLIS_PER_HOUR

MILLIS_PER_DAY

ZERO_CALENDAR

Method Detail

parseDateFormat

parsePrecisionDateTimeLiteral

getTimeZone

checkDateFormat

newDateFormat

unixTimestampToString

unixTimeToString

unixDateToString

intervalYearMonthToString

number

digitCount

powerX

intervalDayTimeToString

dateStringToUnixDate

timeStringToUnixDate

timeStringToUnixDate

timestampStringToUnixDate

unixDateExtract

unixTimestampFloor

unixDateFloor

unixTimestampCeil

unixDateCeil

ymdToUnixDate

ymdToJulian

unixTimestamp