ReflectionTapestryProvider.java :  » Profiler » MessAdmin » clime » messadmin » providers » locale » Java Open Source

/**
 * 
 */
package clime.messadmin.providers.locale;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Locale;

import javax.servlet.http.HttpSession;

import clime.messadmin.providers.spi.LocaleProvider;

/**
 * Note: this provider implementation uses reflexion, to avoid linking against Tapestry libs.
 * @author Cédrik LIME
 */
public class ReflectionTapestryProvider implements LocaleProvider {

  /**
   * 
   */
  public ReflectionTapestryProvider() {
    super();
  }

  /**
   * {@inheritDoc}
   */
  public int getPriority() {
    return 30;
  }

  /**
   * {@inheritDoc}
   */
  public Locale guessLocaleFromSession(HttpSession httpSession) {
    Locale locale = null;

    // Tapestry 3.0: Engine stored in session under "org.apache.tapestry.engine:" + config.getServletName()
    // TODO: Tapestry 4+
    final List tapestryArray = new ArrayList();
    for (Enumeration enumeration = httpSession.getAttributeNames(); enumeration.hasMoreElements();) {
      String name = (String) enumeration.nextElement();
      if (name.indexOf("tapestry") > -1 && name.indexOf("engine") > -1 && null != httpSession.getAttribute(name)) {//$NON-NLS-1$ //$NON-NLS-2$
        tapestryArray.add(httpSession.getAttribute(name));
      }
    }
    if (tapestryArray.size() == 1) {
      // found a potential Engine! Let's call getLocale() on it.
      Object probableEngine = tapestryArray.get(0);
      if (null != probableEngine) {
        try {
          Method readMethod = probableEngine.getClass().getMethod("getLocale", null);//$NON-NLS-1$
          if (null != readMethod) {
            // Call the property getter and return the value
            Object possibleLocale = readMethod.invoke(probableEngine, null);
            if (null != possibleLocale && possibleLocale instanceof Locale) {
              locale = (Locale) possibleLocale;
            }
          }
        } catch (Exception e) {
          // stay silent
        }
      }
    }

    return locale;
  }

}