code: public static boolean isPresent(String klass) {
  		hasText(klass, "Class name must not be empty");
  		try {
  			Class.forName(klass);
  			return true;
  		}
  		catch (Exception ex) {
  			return false;
  		}
  	}
docs: Check that a given class is available on
  classpath.
  
  @param klass Class name.
  @return True if class is available, false otherwise.