Java Date Time - YearMonth.query() Examples

package com.logicbig.example.yearmonth;

import java.time.YearMonth;
import java.time.chrono.Chronology;
import java.time.temporal.TemporalQueries;
import java.time.temporal.TemporalUnit;

public class QueryExample {

    public static void main(String... args) {
        YearMonth y = YearMonth.of(2010, 11);
        System.out.println(y);

        Chronology c = y.query(TemporalQueries.chronology());
        System.out.println(c);

        TemporalUnit u = y.query(TemporalQueries.precision());
        System.out.println(u);
    }
}

package com.logicbig.example.yearmonth;

import java.time.YearMonth;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalQuery;
import java.time.temporal.UnsupportedTemporalTypeException;

public class QueryExample2 {

    public static void main(String... args) {
        YearMonth y = YearMonth.of(1940, 5);
        System.out.println(y);

        Boolean b = y.query(secondWorldWarPeriodQuery);
        System.out.println(b);

        YearMonth y2 = YearMonth.now();
        System.out.println(y2);
        Boolean b2 = y2.query(secondWorldWarPeriodQuery);
        System.out.println(b2);
    }

    private static final TemporalQuery<Boolean> secondWorldWarPeriodQuery = temporal -> {
        if (temporal.isSupported(ChronoField.YEAR) &&
                temporal.isSupported(ChronoField.MONTH_OF_YEAR)) {
            YearMonth y = YearMonth.from(temporal);
            return y.isAfter(YearMonth.of(1939, 9)) && y.isBefore(YearMonth.of(1945, 9));
        }

        throw new UnsupportedTemporalTypeException("The temporal must support year and year-of-month fields");
    };
}