package org.daisy.pipeline.common;
   
   import java.util.HashMap;
   import java.util.Locale;
   import java.util.Map;
   
   public class NormalizeLang {
   
   	/**
  	 * Mapping from three- to two-letter language tags
  	 */
  	private static Map<String,String> langMap = null;
  
  	/**
  	 * Convert three-letter language subtag to two-letter tag if possible.
  	 */
  	public static Locale normalize(Locale locale) {
  		if (langMap == null) {
  			String[] allLanguages = Locale.getISOLanguages(); // all two-letter language tags
  			langMap = new HashMap<String,String>(allLanguages.length);
  			for (String l : allLanguages)
  				langMap.put(new Locale(l).getISO3Language(), l);
  		}
  		String twoLetterLang = langMap.get(locale.getLanguage()); // convert to two-letter
  		if (twoLetterLang != null)
  			return (new Locale.Builder()).setLocale(locale).setLanguage(twoLetterLang).build();
  		return locale;
  	}
  }