Method newHandler

core/src/main/java/io/ddf/DDF.java:864–909

Instantiate a new ADDFFunctionalGroupHandler given its class name @param theInterface @return @throws ClassNotFoundException @throws NoSuchMethodException @throws SecurityException @throws InvocationTargetException @throws IllegalArgumentException @throws IllegalAccessException @throws Inst

(Class<I> theInterface)

   * @throws InstantiationException
   */
  @SuppressWarnings("unchecked")
  protected <I> I newHandler(Class<I> theInterface) {
    if (theInterface == null) return null;

    String className = null;

    try {
      className = Config.getValueWithGlobalDefault(this.getEngine(), theInterface.getSimpleName());
      mLog.info(">>> className = " + className);
      if (Strings.isNullOrEmpty(className)) {
        mLog.error(String.format("Cannot determine classname for %s from configuration source [%s] %s",
                theInterface.getSimpleName(), Config.getConfigHandler().getSource(), this.getEngine()));
        return null;
      }

      Class<?> clazz = Class.forName(className);

      if (Modifier.isAbstract(clazz.getModifiers())) {
        throw new InstantiationError(String.format("Class %s is abstract and cannot be instantiated", className));
      }

      Constructor<ADDFFunctionalGroupHandler> cons = (Constructor<ADDFFunctionalGroupHandler>) clazz
              .getDeclaredConstructor(new Class<?>[] { DDF.class });

      if (cons != null) cons.setAccessible(true);

      return cons != null ? (I) cons.newInstance(this) : null;

    } catch (ClassNotFoundException cnfe) {
      mLog.error(String.format("Cannot instantiate handler for [%s] %s/%s", this.getEngine(),
              theInterface.getSimpleName(), className), cnfe);
    } catch (NoSuchMethodException nsme) {
      mLog.error(String.format("Cannot instantiate handler for [%s] %s/%s", this.getEngine(),
              theInterface.getSimpleName(), className), nsme);
    } catch (IllegalAccessException iae) {
      mLog.error(String.format("Cannot instantiate handler for [%s] %s/%s", this.getEngine(),
              theInterface.getSimpleName(), className), iae);
    } catch (InstantiationException ie) {
      mLog.error(String.format("Cannot instantiate handler for [%s] %s/%s", this.getEngine(),
              theInterface.getSimpleName(), className), ie);
    } catch (InvocationTargetException ite) {
      mLog.error(String.format("Cannot instantiate handler for [%s] %s/%s", this.getEngine(),
              theInterface.getSimpleName(), className), ite);
    }
    return null;
  }


  @Override