Linux system kenel adopts the Netfilter mechanism ,which is a structural bottom frame for expanding various network service after 2.4 version.

Linux的系统内核自2.4.版采用了Netfilter机制，它是在内核中扩展各种网络服务的结构化底层框架。

Workflow realization base on JAVA was given, including kenel interface, main classes and workflow engine.File flow, examine and approve flow function of the system were realized based on the workflow.

现了协同网络税务办公系统，给出了使用JAVA语言的流的现，包流的核心接口类、主要类的现以及流引擎的现，并在该流基础上，现了该系统的公文流转、审批流程设置等主要办公业务。