基于Java平台的多语言混合编程

Java领域混合语言编程时代已经到来。本文首先回顾静态类型语言和动态类型语言、命令式语言和声明式语言的基本概念和各自的优缺点,然后介绍Java语言的发展趋势和基于Java Virture Machine的代表性语言Jython、JRuby、Groovy、Scala和Clojure,最后指出软件项目的未来在于混合语言编程,Java仍将是JVM生态系统中的重要组成部分。     

使用Java扩展Matlab

为了能结合Java和Matlab两者的优点,构造功能更加强大的科学计算环境,对使用Java语言扩展Matlab主开发环境自身功能的关键技术进行了研究.首先介绍了使用Java扩展Matlab的基本方法,在此基础上结合项目实践中对复杂图形用户接口的需要,提出了一种在Java对象中通过Matlab接口对象访问当前Matlab会话的方法.给出了两个短小完整实例,可用于进一步扩展与重用.     

基于HPJava集群系统的环境搭建与性能分析

Bcwulf集群系统是基于广泛应用的高性能网络环境的由一些微机组成的系统,它可以运行于很多操作系统,如Linux、Windows.Java在作为科学与工程计算语言方面,并没有显著的缺点,却有一些明显的优点.随着Java编译技术的进步,用户会发现用Java编写新应用程序将变得更有吸引力.HPJava语言作为一种支持科学和并行计算的Java新扩展语言,尤其适合大型的并行编程和分布式存储的计算机.HPJava是用Java来实现科学和并行编程的环境,它是基于Java语言的扩充.主要介绍了HPJava在Ljnux系统下构建集群的方法,并用矩阵相乘算法对该系统进行了性能分析.     

基于多线程Java程序安全行为模型的静态检查对策探析

本文通过参数化扩展上下文无关文法作为其安全相关行为模型的抽象表示,针对Java多线程序研究,总结出了从多线程Java程序自动生成安全相关行为模型的方法,该方法应用到携带模型代码方法的实现框架中,形象的描述了静态检查该模型是否满足安全策略的实现,同时为安全执行非信任多线程Java移动代码提供了有效支持。本文合理的使用静态分析多线程Java程序的措施,来进行相关安全性的检查,从中来考察出多线程Java程序的相关安全行为。     

基于Cocoon+XSP框架的网站开发技术

XSP是一种基于Java和XML的能产生动态Web内容的服务器端语言。在Internet应用程序开发中,使用XSP可以实现静态内容、表现形式和程序逻辑的分离,而这种分离是通过Apache Cocoon实现的。Cocoon 是一个用Java语言编写的、提供静态和动态Web内容的,基于XML的Web出版框架。XSP与Cocoon的结合大大提高了站点的开发速度以及站点的可管理性。     

多线程Java程序安全行为模型的静态检查方法

多线程作为支持程序结构化和并行化的重要机制,其应用越来越广泛,多线程应用程序的安全性也成为新的研究热点之一.针对Java多线程程序,文中采用参数化扩展上下文无关文法作为其安全相关行为模型的抽象表示,给出了从多线程Java程序自动生成安全相关行为模型的方法,形式地描述了静态检查该模型是否满足安全策略的实现,并应用到携带模型代码方法的实现框架中.该方法为安全执行非信任多线程Java移动代码提供了有效支持.     

一种基于关联分析与N-Gram的错误参数检测方法

为了检测软件系统中存在错误参数的函数调用,本文提出了一种基于关联分析和N-Gram语言模型的静态检测方法（ANiaD）.基于海量开源代码,构建了关联分析模型以挖掘参数间存在的强关联规则.针对参数间存在强关联规则的函数调用构建N-Gram语言模型.基于训练过的N-Gram模型,计算给定函数调用语句正确的概率.低概率的函数调用被报告为异常函数调用.基于10个开源Java项目对该方法进行实验验证.实验结果表明该方法检测的查准率约43.40%,显著高于现有的基于相似度的检测方法（查准率25%）.     

基于HPJava集群系统的环境搭建与性能分析

Beowulf集群系统是基于广泛应用的高性能网络环境的由一些微机组成的系统,它可以运行于很多操作系统,如Linux、Windows。Java在作为科学与工程计算语言方面,并没有显著的缺点,却有一些明显的优点。随着Java编译技术的进步,用户会发现用Java编写新应用程序将变得更有吸引力。HPJava语言作为一种支持科学和并行计算的Java新扩展语言,尤其适合大型的并行编程和分布式存储的计算机。HPJava是用Java来实现科学和并行编程的环境,它是基于Java语言的扩充。主要介绍了HPJava在Linux系统下构建集群的方法,并用矩阵相乘算法对该系统进行了性能分析。     

基于Java语言的手机软件开发技术分析

随着智能手机的高速发展,手机软件开发成为了当下热门行业。本文以Java语言为基础,通过分析Java语言的概述及手机软件应用程序及架构,简要叙述基于Java语言下手机软件开发技术,最后以基于Java语言对手机加密软件开发实例进行探讨和分析,提高对Java语言在手机软件开发技术更加直观的了解,对于基于Java语言开发手机软件具有借鉴和参考价值。     

基于.NET平台的面向方面编程语言Eos

目前面向方面编程(AOP)的主流工具是基于Java平台的AspectJ。该文论述了基于.NET平台的新AOP技术——Eos语言,该语言扩展了C#语言,引入一套完整的AOP语法,并提供Eos专用编译器,使其性能高于其他AOP实现技术。支持多语言的.NET平台的应用使跨语言应用AOP成为可能。     

基于契约式设计的Java编译器实现

本文通过实现一个基于VeriJava语法与语义检查、验证的编译器,试图在编译阶段通过对方法,类等先决条件与后置条件的验证,在逻辑上保证方法的正确性,帮助开发人员在开发的过程中及时找到设计错误或协调沟通问题,促进交流与理解,使开发过程更为完善。     

Featherweight Java with dynamic and static overloading

We propose FMJ (Featherweight Multi Java), an extension of Featherweight Java with encapsulated multi-methods thus providing dynamic overloading. Multi-methods (collections of overloaded methods associated to the same message, whose selection takes place dynamically instead of statically as in standard overloading) are a useful and flexible mechanism which enhances re-usability and separation of responsibilities. However, many mainstream languages, such as, e.g., Java, do not provide it, resorting to only static overloading.The proposed extension is conservative and type safe: both “message-not-understood” and “message-ambiguous” are statically ruled out. Possible ambiguities are checked during type checking only on method invocation expressions, without requiring to inspect all the classes of a program. A static annotation with type information guarantees that in a well-typed program no ambiguity can arise at run-time. This annotation mechanism also permits modeling static overloading in a smooth way.Our core language can be used as the formal basis for an actual implementation of dynamic (and static) overloading in Java-like languages.     

Java在基于WEB的嵌入式系统中的应用

该文提出了一种基于uClinux嵌入式操作系统的嵌入式系统中,使用Java实现嵌入式实时数据采集系统中数据在WEB中实时图形化显示的方案。该方案弥补uClinux不支持java的缺憾,实现了嵌入式数据采集系统数据的动态WEB显示。     

Mumbo: A Rule-Based Implementation of a Run-time Program Generation Language

We describe our efforts to use rule-based programming to produce a model of Jumbo, a run-time program generation (RTPG) system for Java. Jumbo incorporates RTPG following the simple principle that the regular compiler — or, rather, its back-end — can be used both for ordinary, static compilation and for run-time compilation. This tends to produce a run-time compiler that is inefficient but potentially subject to improvement by partial evaluation. However, the complexity of the language and compiler have made it difficult for us to achieve actual optimization. The model, written in Maude, preserves all the essential ingredients of Jumbo, but operates on a simplified language, called Mumbo. The simplification in the language together with Maude's support for code rewriting has allowed us to make rapid progress. We discuss the model in detail, the kinds of optimizations we have obtained, and the impact on the Jumbo project.     

Java 3D实现VRML浏览器新途径

Java是一种网络语言,Java 3D是Java语言在三维图形领域的扩充,它继承了Java许多优良的特性,Java3D能实现VRML绘制的所有三维图形,通过对Java 3D实现编译浏览VRML文件的分析,简要叙述了Java 3D的几何形体绘制、动画、交互技术,介绍了用Java语言编译VRML文件中遇到的一些技术问题。     

Delegation by object composition

Class inheritance and method overriding, as provided by standard class-based languages, are often not flexible enough to represent objects with some dynamic behavior. In this respect, object composition equipped with different forms of method body lookup is often advocated as a more flexible alternative to class inheritance since it takes place at run time, thus permitting the behavior of objects to be specialized dynamically. In this paper, we illustrate Incomplete Featherweight Java (IFJ), an extension of Featherweight Java with a novel linguistic construct, the incomplete object. Incomplete objects require some missing methods which can be provided at run time by composition with another (complete) object. Furthermore, we present two mechanisms for the method body lookup on (composed) objects, one based on delegation and the other based on consultation. Thanks to the design of the language, the consultation-based lookup is a simple extension of the delegation-based one. Both mechanisms are disciplined by static typing, therefore the language enjoys type safety (which implies no “message-not-understood” run-time errors) and avoids possible accidental overrides due to method name clashes.     

Java性能优化技术综述

Java由于其简单、面向对象、独立于硬件体系结构、安全等特点在各种应用领域内获得广泛的应用,但在很多情况下其运行性能仍有待提高.优化Java应用的运行性能成为当前业界迫切要解决的问题和当前研究的热点.本文简要回顾了当前在Java性能优化方面的最新研究成果,对其中的关键技术进行了深入探讨,并结合作者的经验提出对未来发展的一些看法.     

新一代的网站开发技术XSP

本文介绍了一个全新的基于XML的Web开发技术XSP。XSP是一种基于Java和XML的能产生动态Web内容的服务器端语言。使用XSP可以实现Web的静态内容、表现形式和程序逻辑的分离,而这种分离是通过Apache Cocoon实现的。XSP与Cocoon的结合大大提高了站点的开发速度以及站点的可管理性。     

Java in high performance environments

Java programs are executed by a Java virtual machine (JVM), which interprets intermediate compiled bytecode that is nominally platform independent. Although early versions of Java interpreted unoptimized bytecode in a relatively unsophisticated manner, recent developments including static analysis, just-in-time compilation, JVM optimization, and instruction-level optimizations have improved execution efficiency. Consequently, Java is now competitive with C and C++ for some applications and on some platforms. Despite Java's increasing popularity, there is a lingering perception that deficiencies in the language make it unsuitable for high-performance computing. In this paper we address some of those deficiencies and discuss the suitability of using Java in a distributed environment.