软件的易维护性是指理解、改正、改进软件的难易程度。通常影响软件易维护性的因素有易理解性、易修改性和(25)。

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Originally, the World-Wide Web was designed as information medium for (71) research teams. A deliberately simple implementation model was chosen to make it as simple as possible for authors to (72) documents to the web, and to (73) these in the sense of updating content. This implementation model is centered around the notion of resources, usually file-base D. For the (74) intended use of the web, resources presented a useful abstraction, as they related to relatively self-contained chunks of information such as research publications and (75) pages. Such chunks of information typically could be set up and maintained independently of other resources, so that resources were the appropriate abstraction for composition and modification.

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UML-based tools are often used for J2EE/.NET application analysis and design, both because UML's object orientation is ideal for the J2EE/.NET implementation(66)and because of the expanding scope and complexity of today's enterprise endeavors.(67)the approaches diverge at the coding/implementation phase, a common set of analysis and design techniques applies to both J2EE and.NET.

 The use of a virtual, machine(VM)architecture is also common to J2EE and .NET. Application development tools(68)intermediate-level code instead of platform-specific binary code, which means the VM interprets that code in real time or performs Just-In-Time(JIT)compilation; the Microsoft VM always runs JIT-compiled code. This VM-based model results in(69)-independent applications and is conducive to the late-binding technique that's(70)to the OO approach.