OsgiUtil.java

/**
 *  Copyright 2009, 2010 The Regents of the University of California
 *  Licensed under the Educational Community License, Version 2.0
 *  (the "License"); you may not use this file except in compliance
 *  with the License. You may obtain a copy of the License at
 *
 *  http://www.osedu.org/licenses/ECL-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an "AS IS"
 *  BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 *  or implied. See the License for the specific language governing
 *  permissions and limitations under the License.
 *
 */

package ch.entwine.weblounge.bridge.oaipmh.util;

import org.apache.commons.lang.StringUtils;
import org.osgi.service.cm.ConfigurationException;
import org.osgi.service.component.ComponentContext;

import java.util.Dictionary;

/**
 * Collection of utility function around OSGi.
 */
public final class OsgiUtil {

  private OsgiUtil() {
  }

  /**
   * Get a mandatory, non-blank value from a component context.
   * 
   * @throws RuntimeException
   *           key does not exist or its value is blank
   */
  public static String getContextProperty(ComponentContext cc, String key) {
    String p = cc.getBundleContext().getProperty(key);
    if (StringUtils.isBlank(p))
      throw new RuntimeException("Please provide context property " + key);
    return p;
  }

  /**
   * Get a mandatory, non-blank value from a dictionary.
   * 
   * @throws ConfigurationException
   *           key does not exist or its value is blank
   */
  public static String getCfg(Dictionary d, String key)
      throws ConfigurationException {
    Object p = d.get(key);
    if (p == null)
      throw new ConfigurationException(key, "does not exist");
    String ps = p.toString();
    if (StringUtils.isBlank(ps))
      throw new ConfigurationException(key, "is blank");
    return ps;
  }

  /**
   * Get a mandatory integer from a dictionary.
   * 
   * @throws ConfigurationException
   *           key does not exist or is not an integer
   */
  public static int getCfgAsInt(Dictionary d, String key)
      throws ConfigurationException {
    try {
      return Integer.parseInt(getCfg(d, key));
    } catch (NumberFormatException e) {
      throw new ConfigurationException(key, "not an integer");
    }
  }

  /**
   * Check the existence of the given dictionary. Throw an exception if null.
   */
  public static void checkDictionary(Dictionary properties,
      ComponentContext componentContext) throws ConfigurationException {
    if (properties == null) {
      String dicName = componentContext.getProperties().get("service.pid").toString();
      throw new ConfigurationException("*", "Dictionary for " + dicName + " does not exist");
    }
  }

  public interface UpdateHandler {
    void updated(Dictionary dictionary);

    void deleted();
  }
}