LocaleHelper.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright 2006 - 2008 Pentaho Corporation.  All rights reserved.
 */
package org.pentaho.platform.util.messages;

import java.nio.charset.Charset;
import java.text.DateFormat;
import java.text.NumberFormat;
import java.util.Locale;

import org.pentaho.platform.util.logging.Logger;

public class LocaleHelper {

  private static final ThreadLocal<Locale> threadLocales = new ThreadLocal<Locale>();
  private static final ThreadLocal<Locale> threadLocaleOverride = new ThreadLocal<Locale>();

  public static final int FORMAT_SHORT = DateFormat.SHORT;

  public static final int FORMAT_MEDIUM = DateFormat.MEDIUM;

  public static final int FORMAT_LONG = DateFormat.LONG;

  public static final int FORMAT_FULL = DateFormat.FULL;

  public static final int FORMAT_IGNORE = -1;

  private static Locale defaultLocale;

  public static final String UTF_8 = "UTF-8"; //$NON-NLS-1$

  private static String encoding = LocaleHelper.UTF_8;

  public static final String LEFT_TO_RIGHT = "LTR"; //$NON-NLS-1$

  private static String textDirection = LocaleHelper.LEFT_TO_RIGHT;

  public static void setDefaultLocale(final Locale newLocale) {

    LocaleHelper.defaultLocale = newLocale;
  }

  public static Locale getDefaultLocale() {
    return LocaleHelper.defaultLocale;
  }

  public static void setLocaleOverride(final Locale localeOverride) {
    LocaleHelper.threadLocaleOverride.set(localeOverride);
  }

  public static Locale getLocaleOverride() {
    return LocaleHelper.threadLocaleOverride.get();
  }
  
  public static void setLocale(final Locale newLocale) {
    LocaleHelper.threadLocales.set(newLocale);
  }

  public static Locale getLocale() {
    Locale override = LocaleHelper.threadLocaleOverride.get();
    if (override != null) {
      return override;
    }
    Locale rtn = LocaleHelper.threadLocales.get();
    if (rtn != null) {
      return rtn;
    }
    LocaleHelper.defaultLocale = Locale.getDefault();
    LocaleHelper.setLocale(LocaleHelper.defaultLocale);
    return LocaleHelper.defaultLocale;
  }

  public static void setSystemEncoding(final String encoding) {

    Charset platformCharset = Charset.forName(encoding);
    Charset defaultCharset = Charset.defaultCharset();

    if (platformCharset.compareTo(defaultCharset) != 0) {
      Logger.warn(LocaleHelper.class.getName(), Messages.getInstance().getString("LocaleHelper.WARN_CHARSETS_DONT_MATCH",
          platformCharset.name(), defaultCharset.name()));
    }

    LocaleHelper.encoding = encoding;
  }

  public static void setTextDirection(final String textDirection) {
    // TODO make this ThreadLocal
    LocaleHelper.textDirection = textDirection;
  }

  public static String getSystemEncoding() {
    return LocaleHelper.encoding;
  }

  public static String getTextDirection() {
    // TODO make this ThreadLocal
    return LocaleHelper.textDirection;
  }

  public static DateFormat getDateFormat(final int dateFormat, final int timeFormat) {

    if ((dateFormat != LocaleHelper.FORMAT_IGNORE) && (timeFormat != LocaleHelper.FORMAT_IGNORE)) {
      return DateFormat.getDateTimeInstance(dateFormat, timeFormat, LocaleHelper.getLocale());
    } else if (dateFormat != LocaleHelper.FORMAT_IGNORE) {
      return DateFormat.getDateInstance(dateFormat, LocaleHelper.getLocale());
    } else if (timeFormat != LocaleHelper.FORMAT_IGNORE) {
      return DateFormat.getTimeInstance(timeFormat, LocaleHelper.getLocale());
    } else {
      return null;
    }

  }

  public static DateFormat getShortDateFormat(final boolean date, final boolean time) {
    if (date && time) {
      return DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, LocaleHelper.getLocale());
    } else if (date) {
      return DateFormat.getDateInstance(DateFormat.SHORT, LocaleHelper.getLocale());
    } else if (time) {
      return DateFormat.getTimeInstance(DateFormat.SHORT, LocaleHelper.getLocale());
    } else {
      return null;
    }
  }

  public static DateFormat getMediumDateFormat(final boolean date, final boolean time) {
    if (date && time) {
      return DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM, LocaleHelper.getLocale());
    } else if (date) {
      return DateFormat.getDateInstance(DateFormat.MEDIUM, LocaleHelper.getLocale());
    } else if (time) {
      return DateFormat.getTimeInstance(DateFormat.MEDIUM, LocaleHelper.getLocale());
    } else {
      return null;
    }
  }

  public static DateFormat getLongDateFormat(final boolean date, final boolean time) {
    if (date && time) {
      return DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, LocaleHelper.getLocale());
    } else if (date) {
      return DateFormat.getDateInstance(DateFormat.LONG, LocaleHelper.getLocale());
    } else if (time) {
      return DateFormat.getTimeInstance(DateFormat.LONG, LocaleHelper.getLocale());
    } else {
      return null;
    }
  }

  public static DateFormat getFullDateFormat(final boolean date, final boolean time) {
    if (date && time) {
      return DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.FULL, LocaleHelper.getLocale());
    } else if (date) {
      return DateFormat.getDateInstance(DateFormat.FULL, LocaleHelper.getLocale());
    } else if (time) {
      return DateFormat.getTimeInstance(DateFormat.FULL, LocaleHelper.getLocale());
    } else {
      return null;
    }
  }

  public static NumberFormat getNumberFormat() {
    return NumberFormat.getNumberInstance(LocaleHelper.getLocale());
  }

  public static NumberFormat getCurrencyFormat() {
    return NumberFormat.getCurrencyInstance(LocaleHelper.getLocale());
  }

  public static String getClosestLocale(String locale, String locales[]) {
    // see if this locale is supported
    if (locales == null || locales.length == 0) {
      return locale;
    }
    if (locale == null || locale.length() == 0) {
      return locales[0];
    }
    String localeLanguage = locale.substring(0, 2);
    String localeCountry = (locale.length() > 4) ? locale.substring(0, 5) : localeLanguage;
    int looseMatch = -1;
    int closeMatch = -1;
    int exactMatch = -1;
    for (int idx = 0; idx < locales.length; idx++) {
      if (locales[idx].equals(locale)) {
        exactMatch = idx;
        break;
      } else if (locales[idx].length() > 1 && locales[idx].substring(0, 2).equals(localeLanguage)) {
        looseMatch = idx;
      } else if (locales[idx].length() > 4 && locales[idx].substring(0, 5).equals(localeCountry)) {
        closeMatch = idx;
      }
    }
    if (exactMatch != -1) {
      // do nothing we have an exact match
    } else if (closeMatch != -1) {
      locale = locales[closeMatch];
    } else if (looseMatch != -1) {
      locale = locales[looseMatch];
    } else {
      // no locale is close , just go with the first?
      locale = locales[0];
    }
    return locale;
  }
}