package ca.uhn.hl7v2.hoh.util;
   
   import java.io.InputStream;
   import java.util.Properties;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   /**
   * Class to log the HAPI version when HAPI is first used (mostly for troubleshooting purposes)
   */
  public class VersionLogger {
  
      private static final Logger LOG = LoggerFactory.getLogger(VersionLogger.class);
  	private static boolean ourInitialized = false;
      private static String ourVersion; 
      /**
       * Non-instantiable
       */
      private VersionLogger() {
          // nothing
      }
  
      /**
  	 * @return Returns the current version of HAPI
  	 */
  	public static String getVersion() {
  		init();
  		return ourVersion;
  	}
  
  	/**
       * Logs the HAPI version on the first time this method is invoked, does nothing afterwards
       */
      public static void init() {
          if (!ourInitialized) {
              try {
                  InputStream is = VersionLogger.class.getResourceAsStream("/ca/uhn/hl7v2/hoh/hoh-version.properties");
                  Properties p = new Properties();
                  p.load(is);
                  ourVersion = p.getProperty("version");
                  String build = p.getProperty("build");
  				LOG.info("HL7 over HTTP (HAPI) library version " + ourVersion + " - Build " + build);
              } catch (Exception e) {
                  // ignore
              }
              ourInitialized = true;
          }
      }
      
  }