摘要
随着嵌入式系统日益普及，基于嵌入式系统开发应用软件的需求越来越广泛，但是嵌入式系统资源(如CPU处理能力、内存容量、功耗等)有限，从而使在该系统上运行的应用软件的大小及运行速度受到了不同程度的限制。解决这些问题的方法之一是采用裁减的客户端中间件开发平台，并使用组件技术进行应用软件开发。
本文对中间件CORBA和QPE开发平台的软硬件环境进行了深入的分析，基于QPE存储容量和CPU处理速度等硬件环境的局限，对CORBA的两种工作方式，既静态调用方式和动态调用方式进行比较，论述了‘设计基于QPE客户端中间件’应该采用静态调用工作方式的原因，设计并实现了‘客户端中间件模型QORB’。该中间件模型依据QPE开发平台的特点，采用静态调用方式，对已有MICO进行了大幅度的裁减，不但实现了客户端ORB最小化，而且符合CORBA规范，从而解决了资源有限的问题。QORB中间件采用GIOP／IIOP协议，客户端应用程序通过该中间件平台访问服务器端的远程目标对象，服务器端可以是台式机或专用服务器。
面向对象技术和组件技术是当今两种比较流行的软件程序设计方法。在对面向对象技术、组件技术深入研究的基础上，使用组件化的程序设计方法，依据MICO的IDL规范设计了PDA个人信息管理的接口，实现了客户端和服务器端的应用程序。客户端的应用程序通过本文设计的客户端中间件QORB访问服务器端的目标对象，目标对象执行相应的请求，并将操作结果通过客户端中间件返回给客户端应用程序。这样的应用系统运行速度较快，代码的重用性较高，开发周期短，同时也提高了系统的稳定性和可靠性。由于接口的定义一般不变，因而应用程序升级更加容易。
With the increasingly widespread use of the embedded system, It has more and more application programmers. According to the characteristics of embedded system that have limited resources. Therefore ,speed and scale application programmers are limited. One of methods of settling to above problem ,To use cutted middleware development flat of client and component technology will developed in application programmers.
CORBA is analyzed in depth , and designed and implemented middleware model of client on QPE, Due to characteristics of development flat of QPE , Two kinds of work method of CORBA .namely static invocation is compared with dynamic invocation.thus, QORB is applied static invocation . middleware model of client in QPE flat is designed and implemented .according to QPE development flat,using static invation , we must cut down strongly MICO System .implementing the least of ORB of client and according with CORBA Specification , we solve the problem of limited resource . using the protocol of GIOP/IIOP, application programmers of client invocate object of remote trough middleware development flat .Because of requiring of system's resource ?server is usually desktop computer .
There are two better popular method of programmer's design, Object and Component Technology .Through deeply studying them , applying component method of designing programmers in designing middleware flat of client and CORBA Interface Definition Language are designed component interface of Personal Information Management .implemented application programmer of client and server. Through QORB application programmer of client invoke object object of server, and it implement this request, through QORB the result of implement send application programmer of client. The speed of application system is better .The same code is frequency applied. The time of development shorten . The stability and reliability of system are advanced . Because the definition of component interface is invariability , the upgrade of application programmer is easier.
引文
【1】The Common Object Broke :Architecture and Specification 2.3.OMG. Octerber 1999
【2】The Common Object Broke :Architecture and Specification 2.4.OMG. Octerber 2000
【3】c++ Language Mapping Specification OMG. June 1999
【4】CORBA services: Common Object Services Specification .OMG.1998
【5】Naming Services Specification .OMG. April 2000
【6】IDL Type Extensions RFP: OMG.March 2000
【7】Generic Programming and STL
【8】Unified Modeling Language User Guide Booch,G,et a1,1998
【9】Design Patterns Gamma, E,et,al 1994
【10】IEEE Standards Collection. Software Engineering. 1994 Edition. IEEE, 1999
【11】ockschmidt K. Inside OLE2. Microsoft Press, 1994
【12】Berson A. Client/Sever Architecture. McGraw-Hill, 1992
【13】Object Management Group. The Common Object Request Broker: Architecture and Specification. Revision 2.0.1995
【14】[1][美]OMG编著．CORBA系统结构、原理与规范．北京：电子工业出版社，2000
【15】Arno Puder，Kay Rmer．MICO——开源CORBA的实现．北京：中国电力出版社，2001，7
【16】云晓春，方滨兴．基于部件设计的可靠性研究．计算机工程．1999，Vol．25
【17】何国斌，马世龙．基于构件的软件开发的方法与实践．计算机工程与应用．2000．10
【18】[美]Michi Henning，Steve Vinoski著．基于C++ COBRA高级编程．北京：清华大学出版社，2000
【19】[日]Dirk Slama[美]Jason Garbis[澳]Perry Russell著．COBRA企业解决方案．北京：机械工业出版社，2000
【20】Frank Buschmann，Regine Meunier，[德]Harts Rohnert，Peter Sommerlad，Michael Stal著．面向模式的软件体系结构 卷1：模式系统．北京：机械工业出版社，2003．1
【21】Amit Dey. Building an Office2K COM addin with VC++-ATL.
【22】Tom Mowbray. "CORBA Design Pattern". John Wiley&Sons,Inc. 1997
【23】Eric Gamma. "Design Patterns". Addison-Weskey. 1995
【24】Mary Shaw, David Garland. Software Architecture: Perspectives on an Emerging Discipline．Prentice Hall(1996)．北京：清华大学出版社，1998．5
【25】Microsoft Corporation著．Outlook2000编程．北京：超品计算机公司，2000
【26】探矽工作室著．嵌入式系统开发圣经．中国青年出版社，2002．1
【27】郭兵等．嵌入式应用软件集成开发环境的比较与分析．计算机应用Vol．21，No．8
【28】James Rumbaugh，Ivar Jacobson，Orady Booth著．UML参考手册．北京：机械
工业出版社，2001
【29】吴际 金茂忠编著．UML面向对象分析．北京：北京航空航天大学出版社，2002．1
【30】 Wendy Boggs,Michael Boggs著. Mastering UML with Rational Rose 2002. 北京:电子工业出版社, 2002.7
【31】Hiroshi Kashima. An Approach for Constructing Web Enterprise Systems on Distributed Objects.
【32】http://www.mico.org/
【33】http://www.pocketix.com/
【34】http://www.orty.com/linux/
【35】http://www.linuxeden.com/edu/
【36】http://www.linux.org.tw/
【37】http://www.linuxbyte.net/
【38】http://www.linuxaid.com.cn/
【39】http://www.hi-pda.com/
【40】http://www.palmpalm.com/
【41】http://www.pda.com.cn
【42】http://palm.on.net.cn/