private String getActionClassName() throws AmbariException {
    String wrappedClassName = getCommandParameterValue(ServerAction.WRAPPED_CLASS_NAME);
    if (null == wrappedClassName) {
      throw new AmbariException("The name of the upgrade action class to execute was not found.");
    }

    return wrappedClassName;
  }
Gets the fully qualified classname of the {@link UpgradeAction} class which
will be executed. This will look in the command parameters of the execution
command for {@link ServerAction#WRAPPED_CLASS_NAME}.


@return the name of the class.
@throws AmbariException
          if the class name could not be found.
ambari-server/src/main/java/org/apache/ambari/server/serveraction/upgrades/PluginUpgradeServerAction.java