import java.time.LocalDate;
import java.time.Month;
import java.time.ZoneId;

/**
 * LocalDate Examples
 * 
 * @author pankaj
 *
 */
public class LocalDateExample
{

    public static void main(String[] args)
    {

        // 當前日期
        LocalDate today = LocalDate.now();
        System.out.println("當前日期=" + today);

        // 通過傳入的參數創建LocalDate對象
        LocalDate firstDay_2014 = LocalDate.of(2014, Month.JANUARY, 1);
        System.out.println("指定日期=" + firstDay_2014);

        // 根據有效輸入創建日期，以下代碼會拋異常，無效輸入，2014年2月沒有29日
        // LocalDate feb29_2014 = LocalDate.of(2014, Month.FEBRUARY, 29);
        // Exception in thread "main" java.time.DateTimeException:
        // Invalid date 'February 29' as '2014' is not a leap year

        // 獲取不同時區的日期 "Asia/Kolkata", you can get it from ZoneId javadoc
        LocalDate todayKolkata = LocalDate.now(ZoneId.of("Asia/Kolkata"));
        System.out.println("當前印度標準日期=" + todayKolkata);

        // java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
        // LocalDate todayIST = LocalDate.now(ZoneId.of("IST"));

        // 從基準日期獲取日期  例如： 01/01/1970
        LocalDate dateFromBase = LocalDate.ofEpochDay(365);
        System.out.println("基準日期的第365天= " + dateFromBase);

        //2014年的第一百天
        LocalDate hundredDay2014 = LocalDate.ofYearDay(2014, 100);
        System.out.println("2014年的第一百天=" + hundredDay2014);
    }

}

import java.time.LocalTime;
import java.time.ZoneId;

/**
 * LocalTime Examples
 * 
 * @author pankaj
 *
 */
public class LocalTimeExample
{

    public static void main(String[] args)
    {

        // Current Time
        LocalTime time = LocalTime.now();
        System.out.println("Current Time=" + time);

        // Creating LocalTime by providing input arguments
        LocalTime specificTime = LocalTime.of(12, 20, 25, 40);
        System.out.println("Specific Time of Day=" + specificTime);

        // Try creating time by providing invalid inputs
        // LocalTime invalidTime = LocalTime.of(25,20);
        // Exception in thread "main" java.time.DateTimeException:
        // Invalid value for HourOfDay (valid values 0 - 23): 25

        // Current date in "Asia/Kolkata", you can get it from ZoneId javadoc
        LocalTime timeKolkata = LocalTime.now(ZoneId.of("Asia/Kolkata"));
        System.out.println("Current Time in IST=" + timeKolkata);

        // java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
        // LocalTime todayIST = LocalTime.now(ZoneId.of("IST"));

        // Getting date from the base date i.e 01/01/1970
        LocalTime specificSecondTime = LocalTime.ofSecondOfDay(10000);
        System.out.println("10000th second time= " + specificSecondTime);

    }

}

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.Month;
import java.time.ZoneId;
import java.time.ZoneOffset;

public class LocalDateTimeExample
{

    public static void main(String[] args)
    {

        // Current Date
        LocalDateTime today = LocalDateTime.now();
        System.out.println("Current DateTime=" + today);

        // Current Date using LocalDate and LocalTime
        today = LocalDateTime.of(LocalDate.now(), LocalTime.now());
        System.out.println("Current DateTime=" + today);

        // Creating LocalDateTime by providing input arguments
        LocalDateTime specificDate = LocalDateTime.of(2014, Month.JANUARY, 1, 10, 10, 30);
        System.out.println("Specific Date=" + specificDate);

        // Try creating date by providing invalid inputs
        // LocalDateTime feb29_2014 = LocalDateTime.of(2014, Month.FEBRUARY, 28,
        // 25,1,1);
        // Exception in thread "main" java.time.DateTimeException:
        // Invalid value for HourOfDay (valid values 0 - 23): 25

        // Current date in "Asia/Kolkata", you can get it from ZoneId javadoc
        LocalDateTime todayKolkata = LocalDateTime.now(ZoneId.of("Asia/Kolkata"));
        System.out.println("Current Date in IST=" + todayKolkata);

        // java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
        // LocalDateTime todayIST = LocalDateTime.now(ZoneId.of("IST"));

        // Getting date from the base date i.e 01/01/1970
        LocalDateTime dateFromBase = LocalDateTime.ofEpochSecond(10000, 0, ZoneOffset.UTC);
        System.out.println("10000th second time from 01/01/1970= " + dateFromBase);

    }

}

import java.time.Duration;
import java.time.Instant;

public class InstantExample
{

    public static void main(String[] args)
    {
        // Current timestamp
        Instant timestamp = Instant.now();
        System.out.println("Current Timestamp = " + timestamp);

        // Instant from timestamp
        Instant specificTime = Instant.ofEpochMilli(timestamp.toEpochMilli());
        System.out.println("Specific Time = " + specificTime);

        // Duration example
        Duration thirtyDay = Duration.ofDays(30);
        System.out.println(thirtyDay);
    }

}

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Period;
import java.time.temporal.TemporalAdjusters;

public class DateAPIUtilities
{

    public static void main(String[] args)
    {

        LocalDate today = LocalDate.now();

        // Get the Year, check if it's leap year
        System.out.println("Year " + today.getYear() + " is Leap Year? " + today.isLeapYear());

        // Compare two LocalDate for before and after
        System.out.println("Today is before 01/01/2015? " + today.isBefore(LocalDate.of(2015, 1, 1)));

        // Create LocalDateTime from LocalDate
        System.out.println("Current Time=" + today.atTime(LocalTime.now()));

        // plus and minus operations
        System.out.println("10 days after today will be " + today.plusDays(10));
        System.out.println("3 weeks after today will be " + today.plusWeeks(3));
        System.out.println("20 months after today will be " + today.plusMonths(20));

        System.out.println("10 days before today will be " + today.minusDays(10));
        System.out.println("3 weeks before today will be " + today.minusWeeks(3));
        System.out.println("20 months before today will be " + today.minusMonths(20));

        // Temporal adjusters for adjusting the dates
        System.out.println("First date of this month= " + today.with(TemporalAdjusters.firstDayOfMonth()));
        LocalDate lastDayOfYear = today.with(TemporalAdjusters.lastDayOfYear());
        System.out.println("Last date of this year= " + lastDayOfYear);

        Period period = today.until(lastDayOfYear);
        System.out.println("Period Format= " + period);
        System.out.println("Months remaining in the year= " + period.getMonths());
    }
}

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class DateParseFormatExample
{

    public static void main(String[] args)
    {

        // Format examples
        LocalDate date = LocalDate.now();
        // default format
        System.out.println("Default format of LocalDate=" + date);
        // specific format
        System.out.println(date.format(DateTimeFormatter.ofPattern("d::MMM::uuuu")));
        System.out.println(date.format(DateTimeFormatter.BASIC_ISO_DATE));

        LocalDateTime dateTime = LocalDateTime.now();
        // default format
        System.out.println("Default format of LocalDateTime=" + dateTime);
        // specific format
        System.out.println(dateTime.format(DateTimeFormatter.ofPattern("d::MMM::uuuu HH::mm::ss")));
        System.out.println(dateTime.format(DateTimeFormatter.BASIC_ISO_DATE));

        Instant timestamp = Instant.now();
        // default format
        System.out.println("Default format of Instant=" + timestamp);

        // Parse examples
        LocalDateTime dt = LocalDateTime.parse("27::四月::2014 21::39::48",
            DateTimeFormatter.ofPattern("d::MMM::uuuu HH::mm::ss"));
        System.out.println("Default format after parsing = " + dt);
    }

}

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;

public class DateAPILegacySupport
{

    public static void main(String[] args)
    {

        // Date to Instant
        Instant timestamp = new Date().toInstant();
        // Now we can convert Instant to LocalDateTime or other similar classes
        LocalDateTime date = LocalDateTime.ofInstant(timestamp,
            ZoneId.of(ZoneId.SHORT_IDS.get("PST")));
        System.out.println("Date = " + date);

        // Calendar to Instant
        Instant time = Calendar.getInstance().toInstant();
        System.out.println(time);
        // TimeZone to ZoneId
        ZoneId defaultZone = TimeZone.getDefault().toZoneId();
        System.out.println(defaultZone);

        // ZonedDateTime from specific Calendar
        ZonedDateTime gregorianCalendarDateTime = new GregorianCalendar().toZonedDateTime();
        System.out.println(gregorianCalendarDateTime);

        // Date API to Legacy classes
        Date dt = Date.from(Instant.now());
        System.out.println(dt);

        TimeZone tz = TimeZone.getTimeZone(defaultZone);
        System.out.println(tz);

        GregorianCalendar gc = GregorianCalendar.from(gregorianCalendarDateTime);
        System.out.println(gc);

    }

}