工作流异常处理技术与方法

首先介绍了工作流异常处理的体系结构,然后详细介绍了异常处理在流程建模中的描述方式和异常处理的四个基本方法：事务特性与程序设计结合法、知识库法、ECA规则法和工作流进化法。最后展望了工作流异常处理的未来发展方向。     

流程违例处理的行为及分析

业务流程运行期间,外部或运行环境中的某些属性与流程设计时所设定的条件不一致时,将导致流程运行时的违例,违例处理方法涉及流程运行时违例的发现和处理。首先介绍了流程的违例及其分类;基于流程违例处理模式,使用CCS偶图对流程工作项级、案例级违例处理以及相关补偿处理进行分析和表述;在违例处理策略讨论的基础上,总结了违例处理模式的基本形式,并通过CCS偶图的动态特征分析了违例处理的动态行为。     

工作流系统中的一种异常处理机制

文中通过对工作流系统可能出现的异常情况进行较详细的分析，提出了利用规则库进行异常处理的模型，并对异常处理规则的数据结构进行了较深入的探讨。     

工作流异常处理的形式描述

异常处理是工作流执行中要解决的主要问题之一，清楚地描述异常处理的过程是最终得到实现的基础。Petri-net对工作流的描述适合于对过程定义进行正确性验证和评价，但描述各种不同条件下的处理策略却很繁琐，采用了一种直观的描述方法对异常处理过程中的元素，即活动、异常处理策略以及处理措施进行了形式化描述，特别是对不同处理策略下的处理过程进行了描述。结合消息机制，分析了一个异常事件出现时，如何处理一个活动实例产生的中间数据，并对事务处理和异常处理的补偿策略进行了比较。描述方法为编码实现提供了很大的方便。     

基于补偿业务生成图的组合服务异常处理方法研究

为提高组合Web服务执行的一致性、可靠性,提出一种基于补偿业务生成图的组合服务异常处理方法.基于业务流程中任务间补偿依赖关系,讨论了补偿业务生成图的自动生成问题.重点讨论了补偿任务、补偿目标和服务转让应用模式,并相应地介绍了支持框架和相关技术.在此基础上设计了补偿依赖关系、补偿业务生成图的自动生成及组合服务执行过程中异常处理算法.当业务流程出现异常采取向前或向后恢复处理时,该方法在保证补偿实现的同时,兼顾补偿服务不存在或补偿服务代价过高的问题,提高了业务流程执行过程中的自动化水平和自适应能力.仿真结果证实,该方法保证了异常发生时组合服务执行的可靠性和一致性.     

Exception Handling in Workflow Systems

In this paper, defeasible workflow is proposed as a framework to support exception handling for workflow management. By using the justified ECA rules to capture more contexts in workflow modeling, defeasible workflow uses context dependent reasoning to enhance the exception handling capability of workflow management systems. In particular, this limits possible alternative exception handler candidates in dealing with exceptional situations. Furthermore, a case-based reasoning (CBR) mechanism with integrated human involvement is used to improve the exception handling capabilities. This involves collecting cases to capture experiences in handling exceptions, retrieving similar prior exception handling cases, and reusing the exception handling experiences captured in those cases in new situations.     

Cross-Organizational Transaction Support for E-Services in Virtual Enterprises

In recent years, workflow management systems have become an accepted technology to support automation in process-centric environments. Lately, organizations concentrate more and more on their core business processes while outsourcing supporting processes to other organizations, thereby forming virtual enterprises. The organizations forming the virtual enterprise operate in a B2B e-commerce setting in which provider organizations perform e-services for consumer organizations. To apply workflow management technology in these virtual enterprises, current workflow management systems need to be extended to offer support for cross-organizational processes. Transaction support, already considered an important issue in intra-organizational workflow management systems, must be extended to deal with the cross-organizational aspects as well. This paper presents a high-level, compensation based transaction model and a flexible architecture to support thistransaction model, as required by cross-organizational workflow processes. Characteristic of the model is the flexibility in rollback semantics by combining rollback modes and rollback scopes. This is supported by a dynamically composed architecture that is configured using the agreements that are specified in an electronic contract that has been established between the participating organizations. The transaction model supported by the dynamically composed architecture is implemented in a prototype system, based on commercial workflow management technology.     

Java异常处理机制研究

异常处理机制是程序设计语言的主要特征,它为开发稳定的软件系统提供了有力的支持.文章对Java语言的异常处理机制以及异常类的层次进行了详细介绍,提出了Java异常处理策略.     

基于Pi演算的跨组织工作流建模研究

传统的工作流建模方法主要用于描述组织内部流程,因而难以描述跨组织工作流面向流程、组合、抽象、涉及多个自治系统通信合作的新特点.针对此问题,提出了一种基于Pi演算的跨组织工作流建模方法,利用Pi演算的并发计算操作符,将跨组织业务流程建模为一组自治且并发执行的组织内子流程的组合,子流程建模为组织内本地流程定义和组织间控制约束的组合.基于Pi演算的弱互相似理论,验证了两个跨组织子流程外部行为的相等性,用于帮助组织内私有流程的外部抽象.基于该方法建立的跨组织工作流模型在子流程间建立了一种松耦合的关系,适用于动态的跨组织环境,同时基于严格的形式化方法,便于分析和验证.     

JAVA异常处理的分析与研究

Java的异常处理机制是其一大特色。该文在介绍Java语言的异常处理技术的基础上,提出了异常处理的设计原则,从而为Java的程序设计实现提供技术上的借鉴。     

Java异常处理策略研究

异常处理机制是程序设计语言的重要标志之一,在程序设计过程中用来处理程序运行中的异常。传统的程序设计语言里异常处理较为繁杂。Java是一种面向对象的程序设计语言,且引入了异常处理机制。合理完备的异常处理可以增强程序运行的可靠性、提高软件的健壮性,可以较为快速地确定错误的位置。文章分析了Java异常处理的逻辑,阐述了异常类、异常处理机制以及异常处理方法,提出了异常处理的一些策略。综合运用这些策略可以使编程人员编写出更加简洁、高效的程序代码。     

Workflow View Based E-Contracts in a Cross-Organizational E-Services Environment

In an e-service environment, workflow involves not only a single organization but also a number of business partners. Therefore, workflow inter-operability in such an environment is an important issue for enacting workflows. In this article, we introduce our approach of using workflow views as a fundamental support for E-service workflow inter-operability and for controlled visibility of (sub-)workflows by external parties. We discuss various aspects of a workflow view, and their semantics with example usage. Furthermore, we develop a contract model based on workflow views and demonstrate how management of e-contracts can be facilitated, with an Internet start-up E-service inter-organization workflow example.     

基于C#的异常处理及应用

C#提供了一种结构化异常处理方法,能处理程序运行时出现的任何意外或异常情况。该方法可使程序区分不同的错误类型,并做出不同的响应,使程序更高效、更健壮,更易于维护。     

Java异常处理机制的研究

异常处理是Java语言的重要语言机制，正确、合理地处理异常对程序的可靠性、健壮性是十分重要的。在分析了异常处理技术的概念和思想后，对异常处理提出了指导原则，并针对检查型异常和非检查型异常的差异，探讨了对应的解决措施。     

Java异常处理的设计原则

异常处理是程序设计中必须重点考虑的问题。在深入剖析Java语言的异常处理机制基础上,对Java异常处理提出了指导原则,从而可以提高程序的安全性和健壮性。     

Adeptflex—Supporting Dynamic Changes of Workflows Without Losing Control

Today's workflow management systems (WFMS_s) are only applicable in a secure and safe manner if the business process (BP) to be supported is well-structured and there is no need for ad hoc deviations at run-time. As only few BPs are static in this sense, this significantly limits the applicability of current workflow (WF) technology. On the other hand, to support dynamic deviations from premodeled task sequences must not mean that the responsibility for the avoidance of consistency problems and run-time errors is now completely shifted to the (naive) end user. In this paper we present a formal foundation for the support of dynamic structural changes of running WF instances. Based upon a formal WF model (ADEPT), we define a complete and minimal set of change operations (ADEPT_flex) that support users in modifying the structure of a running WF, while maintaining its (structural) correctness and consistency. The correctness properties defined by ADEPT are used to determine whether a specific change can be applied to a given WF instance or not. If these properties are violated, the change is either rejected or the correctness must be restored by handling the exceptions resulting from the change. We discuss basic issues with respect to the management of changes and the undoing of temporary changes at the instance level. Recently we have started the design and implementation of ADEPT_workflow, the ADEPT workflow engine, which will make use of the change facilities presented in this paper.     

浅谈C#程序中的异常处理机制

程序设计中,异常是一个不可忽略的元素,因此,有效的异常处理是程序完善的重要标志。重点介绍了C#语言中的异常处理机制。主要包括异常的基础知识、异常处理机制、程序设计中的异常三个部分。异常基础知识部分,讲解了什么是异常,异常发生的情况及主要的异常类,使读者对程序异常有基本的认识。异常处理机制部分,从应用程序和理论两方面对C#语言中对异常的处理机制进行讲解,详细分析了三种异常处理语句。程序设计中的异常部分,通过一个简单的程序开发中的例子扩展异常机制在程序设计中的应用,拓宽软件开发人员的设计思路。     

包含异常处理的Java程序切片

Exception是一类特殊的对象，它在Java方法出错时被创建，并利用try／catch／finally机制抛出、处理异常。本文提出了一种合理的新方法，在系统依赖图中表示异常处理模块，利用图可迭性算法实现了Java程序切片。     

Java异常处理与自定义异常

Java程序运行期间发生的错误称为异常.异常产生后,应有相应的异常处理机制来捕获异常或抛出异常。JDK平台为我们提供了丰富和完整的异常类,通过它们来处理程序运行中的错误,防止错误对程序造成影响,确保程序能够安全运行。当这些异常类不能捕获实际应用中的异常时．就需要用户自定义异常。异常处理和用户自定义异常的正确与灵活运用：将有效地增强程序的交互性。增加程序的完整性。     

基于C++异常处理机制的研究

异常处理是程序开发的一个重要内容,异常处理的好坏关系到程序的友好程度和系统的稳定性。C 是一种纯面向对象的编程语言,其异常处理机制和普通的编程语言有很多不同的地方,有力地增强了C 程序的健壮性和容错性。文中从介绍其运行步骤入手,通过一个简单的例子,详细阐述了C 异常处理机制的规则和栈展开技术,并扼要地对比了函数调用和异常处理的异同点,以便更好地在C 面向对象程序设计中正确使用异常处理机制。