UnitNames.java

package org.andork.unit;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Locale.LanguageRange;
import java.util.Map;

import org.andork.util.StringUtils;

public abstract class UnitNames {
	private static final Map<Locale, UnitNames> map = new HashMap<>();

	static {
		map.put(Locale.ENGLISH, EnglishUnitNames.inst);
	}

	public static String getName(Locale locale, Unit<?> unit, Number value, UnitNameType nameType) {
		UnitNames names = getNames(locale);
		return names.getName(unit, value, nameType);
	}

	public static UnitNames getNames(Locale locale) {
		UnitNames names = map.get(locale);
		if (names == null) {
			Locale origLocale = locale;
			List<LanguageRange> ranges = new ArrayList<>();
			if (!StringUtils.isNullOrEmpty(locale.getLanguage())) {
				ranges.add(new LanguageRange(locale.getLanguage() + "-*"));
			}
			if (!StringUtils.isNullOrEmpty(locale.getCountry())) {
				ranges.add(new LanguageRange("*-" + locale.getCountry()));
			}
			locale = Locale.lookup(ranges, map.keySet());
			if (locale == null) {
				locale = EnglishUnitNames.inst.locale;
			}
			names = map.get(locale);
			map.put(origLocale, names);
		}
		return names;
	}

	public static <T extends UnitType<T>> Unit<T> lookup(Locale locale, String unitText, T unitType) {
		UnitNames names = getNames(locale);
		return names.lookup(unitText, unitType);
	}

	public final Locale locale;

	public UnitNames(Locale locale) {
		super();
		this.locale = locale;
	}

	public abstract String getName(Unit<?> unit, Number value, UnitNameType nameType);

	public abstract <T extends UnitType<T>> Unit<T> lookup(String unitText, T unitType);
}