private static <C extends Command<R>, R extends Serializable> void executeCommand( CommandExecutor<C, R> executor, ZNode executorNode, final QueueEntry<C, R> entry, final NodeContext nodeContext) { String relativePath = entry.getResultPath().substring(executorNode.getPath().length() + 1); final ZNode output = executorNode.child(relativePath); final NodeCommandExecutionListener<C> listener = entry.getListener(); try { C command = entry.getCommand(); listener.onCommandExecutionStarted(command, nodeContext); R result = executor.execute(command, nodeContext); log.debug("Command {} executed", command); listener.onCommandExecuted(command); output.setObject(CommandExecutionResult.success(result)); } catch (Throwable throwable) { // todo add fail event log.error("error during task execution", throwable); output.setObject(CommandExecutionResult.fail(throwable)); } }