Optimizing Java: theory and practice

The enormous popularity of the Internet has made an instant star of the Java programming language. Java's portability, reusability, security and clean design has made it the language of choice for Web-based applications and a popular alternative to C++ for object-oriented programming. Unfortunately, the performance of the standard Java implementation, even with just-in-time compilation technology, is far behind the most popular languages today. The need for an aggressive optimizing compiler for Java is clear. Building on preliminary experience with the JavaSoft bytecode optimizer, this paper explores some of the issues that arise in building efficient implementations of Java. A number of interesting problems are presented by the Java language design, making classical optimization strategies much harder to implement. On the other hand, Java presents the opportunity for some new optimizations, unique for this language. © 1997 John Wiley & Sons, Ltd.     

A software tool for semi-automatic gridification of resource-intensive Java bytecodes and its application to ray tracing and sequence alignment

Computational Grids deliver the necessary computational infrastructure to perform resource-intensive computations such as the ones that solve the problems scientists are facing today. Exploiting Computational Grids comes at the expense of explicitly adapting the ordinary software implementing scientific problems to take advantage of Grid resources, which unavoidably requires knowledge on Grid programming. The recent notion of “gridifying” ordinary applications, which is based on semi-automatically deriving a Grid-aware version from the compiled code of a sequential application, promises users to be relieved from the requirement of manual usage of Grid APIs within their source codes. In this paper, we describe a novel gridification tool that allows users to easily parallelize Java applications on Grids. Extensive experiments with two real-world applications - ray tracing and sequence alignment - suggest that our approach provides a convenient balance between ease of gridification and Grid resource exploitation compared to manually using Grid APIs for gridifying ordinary applications.     

Java程序内存空间优化策略的研究

一、引言基于Java的应用程序在运行时由于受到语言本身的特点和虚拟机的限制,对于客户端硬件配置的要求相对于Vi-sual C~( )和Visual Basic语言编写的程序要高。虽然Java 2对于JDK虚拟机解释器进行了优化处理,但是仍然不能够完全令用户满意。因此,Java程序的开发人员在对程序代码进行优化时,很自然地将关注焦点放在提高运行性能上。然而,Ja-va程序还可以从另一方面得到优化,即对程序所占用内存空间进行优化。很多功能复杂的Java应用程序在运行时由于系统频繁针对内存进行存储交换操作,从而在很大程度上影响了软件运行的性能。程序中存在的内存漏洞造成了程序通过操作系统消耗内存,而没有及时进行对内存空间的复用和释放,这最终造成了程序消耗的内存空间逐渐加大。从软件工程的角度分析,对空间的优化处理主要以两种形式表现出来:降     

用Java实现基于向量空间的搜索引擎优化

介绍了在一个已有搜索引擎的基础上进行前台优化的方法，实现检索的多样化，应用了向量空间信息检索方法，扩展了传统的信息检索，利用HTML文档结构提高了在WWW环境下的检索效率。     

基于Java体系结构的Web服务器性能优化研究

静态Web技术以固定的方式法布信息,限制了系统综合性能的发挥。采用动态Web技术,通过在服务器和客户端两端编程的方法实现对通信双方系统和信息的发布过程的灵活控制,可以在一定程度上提高Web服务的整体性能。通过对Web服务的原理的分析,找出了影响系统性能的关键环节。提出了基于JAVA架构的解决方案,给出了具体优化设计算法,并进行了性能比较和效益的分析评估。理论和实践证明,方案具有较好的适应性和实用价值。     

Hot Java与Java

ＨｏｔＪａｖａ与Ｊａｖａ武汉大学郑懋申佳丽韩郁飞１引言在当今信息爆炸的时代，Ｉｎｔｅｒｎｅｔ被称之为信息高速公路，它将分布在世界不同地域的资源连接起来，是目前世界上最大的计算机互连网络。Ｉｎｔｅｒｎｅｔ上提供的服务非常丰富，而其中ＷｏｒｌｄＷｉｄｅＷ...     

Java语言与Java技术

介绍Ｊａｖａ语言对业界的影响，Ｊａｖａ平台及当前正在发展着的Ｊａｖａ技术。     

Monitoring Java Programs with Java PathExplorer

We present recent work on the development of Java PathExplorer (JPaX), a tool for monitoring the execution of Java programs. JPaX can be used during program testing to gain increased information about program executions, and can potentially furthermore be applied during operation to survey safety critical systems. The tool facilitates automated instrumentation of a program's byte code, which will then emit events to an observer during its execution. The observer checks the events against user provided high level requirement specifications, for example temporal logic formulae, and against lower level error detection procedures, usually concurrency related such as deadlock and data race algorithms. High level requirement specifications together with their underlying logics are defined in rewriting logic using Maude, and then can either be directly checked using Maude rewriting engine, or be first translated to efficient data structures and then checked in Java.     

Java编译程序技术与Java性能

概述了Java编译程序技术,把Java编译程序分成5类:具有解释技术的编译程序;具有及时(JIT)编译技术的编译程序;具有自适应优化技术的编译程序;本地编译程序和翻译程序.详细描述和分析了它们的体系结构和工作原理.同时也分析了编译程序技术对Java性能的影响.     

Java之路

Java已经问世10年了.在这10年间,Java从一种诱人的技术发展成为一种繁荣的经济生态体系.在这个经济生态体系之中,每家软件企业、每个软件开发人员都可以播种、耕耘、收获,聚集属于自己的财富.     

Java处理器技术

本文介绍了几种 Java处理器技术的结构和特点 ,包括 Java虚拟机、采用堆栈结构的 Java处理器、Java协处理器、采用 VL IW技术的 Java并行处理器等 .最后 ,简述了 Java处理器技术的最近发展概况     

Java Pro

用Windows Workflow和Web Services配置分布式商务处理;利用Windows Vista和WCF中的P2P Communication；     

Java supervenience

This paper reports on the development of a language construct designed to solve certain problems in composability at the level of object-oriented programming languages. Features were chosen to investigate how much compositional functionality could be added to core Java with as small a change as possible and in an additive manner. A fairly elegant and effective syntax on core Java resulted in reducing the clutter of the "mechanics" of composition. This construct features eliminating runtime cast and null exceptions within the construct, and the option of parametric covariant override. It does so while avoiding undesirable restrictions or new frameworks. Recently, new techniques intended to improve the composability of software components in the Java ecosystem have been vigorously pursued. Proposals take on the objectives of composition in largescale systems and enterprise applications but often implement on conventional object-oriented languages which face the same kinds of problems from the ground up. Benefitting from those experiences, the present work seeks to provide core Java-level solutions to problems that are analogous to those at the higher-levels. The supervenience construct described in this paper is based on a well-established formulation for composing a relationship over classes with some common behavioral elements, their behavioral intersection. The narrow concern of this construct is the sound composition of components across class families while eliminating certain barriers to runtime type-safety in core Java. The supervenience construct has been applied to certain classic problems and key case studies in composability and extensibility which represent fundamental issues that emerge at every level. The implementation requires no installed runtime frameworks and no changes to the JVM or type system of core Java. It is designed to deploy stand-alone or later integrate with the standard Java compiler and IDEs. The continuing research is now focusing on a more formal proof of its type-safety, applying the reference implementation to mid-scale and distributed applications.     

Pervasive Java

Highlights pervasive Java - a surge of wireless and mobile platform standardization activities led by Sun Microsystems. Driven by a fast-pace proliferation of portable devices and appliances with embedded computers, pervasive Java (also called wireless Java and mobile Java) attempts to bridge the gap between disparate devices and platforms, and profitable business and application development.     

JAVA的安全结构

Ｊａｖａ的安全结构———“沙盒”模型的４个组成部分：内建于Ｊａｖａ虚拟机和语言的安全特性、类的载入结构、类文件校验器、安全管理器和ＪＡＶＡＡＰＩ。     

Leveraging Java applets: toward collaboration transparency in Java

Widespread use of the Internet is giving rise to the need for collaborative applications that link users at remote sites. Many toolkits support the development of collaboration-aware applications, those developed specifically for cooperative work by multiple users. Another approach is collaboration transparency, the collaborative use of applications originally developed for a single user. When the runtime environment supports collaboration transparency, an application programmer need not write new code to make an application collaborative. Thus, collaboration transparency leverages the existing base of single user applications by extending them to collaborative use. We review options for providing collaboration transparency. We also discuss how collaboration transparency can be incorporated into Sun Microsystems' Java, the most widely used vehicle for developing interactive World Wide Web applications     

Java SSH 框架在Java Web 中的应用

SSH 框架是Java Web 开发的常见技术框架集合,包含Struts、Hibernate 和Spring 三个框架,这三个框架在具体 开发应用侧重点都有所不同,各自管理的代码范围也有着较大的区别,当前应用SSH 框架集进行Java Web 项目的开发是web 开发过程中非常流行的开发模式。本文通过对SSH 框架进行简单介绍,探讨各自框架在web 领域具体应用以及Java Web 框架 技术的发展展望,使得读者能够通过本文快速了解SSH 框架及相关技术,同时为开发人员进行快速开发提供有效参考。     

Java平台及应用Java技术的安全问题

应用系统安全性在网络应用技术发展中发挥越来越重要的作用,同时,逐渐成为信息安全管理措施的核心。Java平台即将应用系统安全技术,结合Java技术,提高网络信息时代的安全性。Java平台配置容易,使用便利,提高了安全体系结构的安全性和稳定性。基于此,简要分析了Java平台,提出了应用Java技术的安全问题,以期为相应企业提供借鉴。     

Java虚拟机中Java栈以及相关指令的实现

Java栈是Java虚拟机中运行时数据区的主要组成部分。大部分虚拟机指令的操作都与Java栈中的框架相关联。该文描述了Java栈在Java虚拟机运行中所起的作用,自行设计了一种Java栈的数据结构,提出了一些具有代表性的字节码指令的实现方法。同时总结了Java栈对虚拟机运行效率的影响。