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

Linux系统核自2.4.版本之后采用了Netfilter机制，它核中扩展各种网络服务结构化底层框架。

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语作流现，包括作流核心接口类、主要类现以及作流引擎现，并该作流基础上，现了该系统公文流转、审批流程设置等主要办公业务。