Java可视虚拟机的研究与实现

【作者】 申剑；

【导师】 吴伟民；

【作者基本信息】 广东工业大学 ， 计算机应用， 2004， 硕士

【摘要】 虽然Visual Basic、Visual C++和Delphi等面向程序界面可视化的程序设计语言已经十分流行，但迄今为止，还没有出现真正意义上的可视化编程环境。目前广泛使用的各种编译和运行环境向用户反馈的都是字符信息，难以直观地动态反映程序的控制流程和复杂数据的抽象关系，程序的运行和调试主要依赖编程者的抽象思维和逻辑分析能力。 可视化技术具有交互性、多维性和可视性等特点。将程序的编译和运行环境可视化，可以使程序和数据的表达更加直观，用户能够静态或者动态地直接观察程序的执行过程和数据及其之间关系的变化，从而降低程序分析、设计和调试过程的抽象性和难度。 本课题研究并实现一个Java可视虚拟机。首先，对Java虚拟机(JVM)一些关键技术进行了深入细致的分析，确保对其运行机理、JavaAPI、本地方法库、JVM运行结构、垃圾收集等细节具有全面准确的理解。然后，提出了一个Java可视虚拟机(JVVM)的结构模型，并进行了具体设计和初步实现。 这个JVVM充分利用了Java编译器产生的class文件包含的各种信息，提出了用类结构概念来解决面向对象的特性，实现了Java基本class文件的读取、数组对象的实现、基本Java操作码的实现、本地库的DLL实现、JVM运行结构可视显示、一些数据结构在运行时的动态可视化、垃圾回收算法的可视化，在实现中将所有类型都统一起来，取得了很好的效果。为最终研发Java的可视化编程环境提供了一个基本原型，并积累了技术和经验。 本文的内容组织如下：第一章介绍可视化编程技术的背景、现状以及研究Java可视虚拟机的意义，并介绍了本课题的主要内容；第二章分析Java虚拟机的结构模型和关键技术，介绍了这些技术的原理和成因，提出了实现Java可视虚拟机的技术方案；第三章介绍Java可视虚拟机的设计与实现，具体讨论了JVVM的实现细节；第四章给出了若干测试实例，包括常规测试、本地方法调用测试、多态继承测试等；第五章总结了本课题的工作，并对后续工作以及应用前景进行了讨论。更多还原

【Abstract】 There is no complete visual programming environment by now. The popular visual programming languages, such as Visual Basic, Visual C++ and Delphi and etc., are only oriental to visual program interfaces. They give feedback to users with character information in compiling and running environments, which cannot straightforward reflect control flows of programs and abstract relations of complex data. So it needs programmers’ abstract thinking and logic analysis abilities to complete debugging and running jobs.As known, the visual technology has characteristics of inter-action, visualization and etc. Applying it to compiling and running environments makes programs and data more straightforward to users. In the meantime, users can observe running processes and changes of data in different conditions, which decreases the difficulties and abstractions of programs’ analysis, designing and debugging.The objective of this paper is to design and implement a Java visual virtual machine (JVVM). Firstly, some key technologies are analyzed in details, which gives complete and precise comprehensions of the running mechanisms, JavaAPI, local method base, JVM running structures, rubbish collections and so on. Secondly, a structure model of JVVM is presented. Finally, a detailed designs and elementary implementation are given.This JVVM fully utilizes diversified information of class files produced by Java compilers. It implements some functions, for example, reading and writing of class files, constructing of class structures, implementation of array objects, basic implementation of Java operation codes, implementation of local methods’ DLL, visual display of JVM running structures, visual running of some data structure, visualization of rubbish collection algorithms. This paper provides a prototype of Java visual programming environment, and accumulates the technology and experience for future researches.The structure and organization of this paper is as follows. Chapter I introduces the background of programming technologies, research motive of Java visual machine and main content of the paper. Chapter II analyzes the structure model and the key technologies of Java visual machine, introduce the principles of these technologiesand presents a solution of JVM implementation. Chapter III introduces the design and implementation of JVM, discussing the implementation details of JVVM. Chapter IV gives several testing examples, including normal testing, local method testing and etc. Chapter VI makes a conclusion of this research, and discusses coming research works and application future.更多还原