A portable AWT/Swing architecture for Java game development

Recently, the performance of Java platforms has been greatly improved to satisfy the requirements for game development. However, the rendering performance of Java 1.1, which is still used by about one‐third of current Web browser users, is not sufficient for high‐profile games. Therefore, practically, Java game developers, especially those who use applets, have to take this into consideration in most environments. In order to solve the above problems, this paper proposes a portable window toolkit architecture called the CYC Window Toolkit (CWT) with the ability to: (1) reach high rendering performance particularly in Java 1.1 applications and applets when using DirectX to render widgets in CWT; (2) support AWT/Swing compatible widgets, so hence the CWT can be easily applied to existing Java games; (3) define a general architecture that supports multiple graphics libraries such as AWT, DirectX and OpenGL, multiple virtual machines such as Java VM and .NET CLR, and multiple operating systems (OSs) such as Microsoft Windows, Mac OS and UNIX‐based OSs; (4) provide programmers with one‐to‐one mapping APIs to directly manipulate DirectX objects and other game‐related properties. The CWT has also been applied to an online Java game system to demonstrate the proposed architecture. Copyright © 2006 John Wiley & Sons, Ltd.     

Using Java applets and CORBA for multi-user distributedapplications

The Java language environment, World Wide Web, and Common Object Request Broker Architecture are complementary software technologies, which when used together provide a powerful set of tools for developing and deploying multi-user distributed applications. We describe an approach to building reasonably sophisticated and easy-to-use client software as WWW-downloadable Java applets, which use CORBA to interact effectively with remote server software and thus coordinate and control access to a set of shared resources. We used this approach to reimplement a portion of an existing multi-user distributed application that had been built using the WWW Common Gateway Interface (CGI), then evaluated the differences between the two approaches. We found our method of combining Java applets and CORBA not only practical but in many ways superior to the widely used CGI approach, as well as to a conventional CORBA approach that does not exploit the WWW     

Navigating the applet-browser divide

The World Wide Web has emerged as a new application-delivery platform. In response, developers are offering users sophisticated Web-based Java applets that range from cybershopping carts to complex tools for genome mapping. These applets give you application functionality without taking up space on your hard drive. But trailing behind the applet bounty are new usability questions. A major one is how to make applet navigation seamless in the Web browser domain. Java applets are programs you write in Java and integrate into your Web page. Although applets can provide functionality similar to traditional applications, the applet code need not be installed on the users' hard drive. Instead, the applets execute Java-compatible Web browsers. Unlike standard Web pages, which users simply visit and browse, applet-enhanced pages let the user manipulate applet components and dynamically interact with information. The author discusses tools, techniques and concepts to optimize user interfaces     

Chronicle of a Java Card death

Various attacks are designed to gain access to the assets of Java Card Platforms. These attacks use software, hardware or a combination of both. Manufacturers have improved their countermeasures to protect card assets from these attacks. In this paper, we attempt to gain access to assets of a recent Java Card Platform by combining various logical attacks. As we did not have any information about the internal structure of the targeted platform, we had to execute various attacks and analyze the results. Our investigation on the targeted Java Card Platform lead us to introduce two generic methods to gain access to the assets of Java Card Platforms. One of the new methods we present in this paper is based on the misuse of the Java Card API to build a type confusion and get access to the objects (including cryptographic keys) of a Java Card applet. The other method is a new approach to get access to the return address of the methods in Java Cards with Separate Stack countermeasure. We also propose a pattern that the targeted platform uses to store data and code of applets on the card plus the ability to read and write in the data and code area of the applets in different security contexts. These new attacks occur even in the presence of countermeasures such as Separate Stack for kernel and user data, indirect mapping for objects addressing and firewall mechanisms.     

Accessing embedded systems via WWW: the ProWeb toolset

The ubiquity of Web browsers makes them an ideal generic front end for simple client-server systems. A very suitable area of application is controlling embedded systems, such as network printers, where supporting standard Web browsers is a cost-effective and convenient alternative to developing custom client software for remote administration from different platforms.This paper describes the design and implementation of a flexible communication server to be run directly on the embedded system. It supports different protocols to allow remote access, including HTTP. Thus, the embedded system can be accessed with any Web browser. Its state is represented as a set of Web pages containing dynamically generated information. Java applets included in these Web pages can connect back to the server to subscribe to live data feeds for real-time visualization of the embedded system's state. A GUI builder implemented as a Java applet can be used to customize the visual appearance of these applets.     

Systems programming in Java

The Java programming language has been widely accepted as a general purpose language for developing portable applications, toolkits, and applets. With so much activity in industry and academia in these user-level areas, is it surprising that Java is also an equally capable systems programming language? This article describes our experiences at JavaSoft with using Java as a systems-level programming language during the development of JavaOS. The author discusses the motivations for using Java and shows code examples to demonstrate various system-level primitives, including an Ethernet device driver     

Editorial: Java for computational science and engineering – simulation and modeling

We are pleased to present a set of papers discussing the role of Java in Science and Engineering Simulation. These were presented at a small workshop with 45 participants at Syracuse on 16-17 December 1996. This was very successful, and a follow-up event will be sponsored by ACM in Las Vegas on 21 June 1997. The growing interest in this field is also supported by an email discussion list and other materials collected at the web site http://www.npac.syr.edu/projects/javaforcse. Java and Web technology can be used in many areas of science and engineering computation. These include sophisticated user interfaces and coarse-grain integration of different modules in complex meta-applications. However, also interesting (and controversial) is perhaps the use of Java as the language used for the computationally intense parts of a scientific code. All these areas were discussed at the workshop, with promising initial results and studies reported in each case. Again applications were described both for large-scale event-driven and time-stepped simulations and also for smaller client-side applets aimed at education. The appeal of Java as a simulation language includes its object-oriented characteristics, elegant applet software distribution model and natural support of graphical user interfaces. There are also non-technical reasons to think Java will be very important. In particular, one expects children to learn Java naturally as part of their Web experiences. On entering University, I find it hard to believe that many will be willing to switch from Java to Fortran77 or Fortran90. The papers in this issue fall into five areas. The first paper (‘Java for parallel computing and as a general language for scientific and engineering simulation and modeling’ by Geoffrey C. Fox and Wojtek Furmanski) is a general overview and the next three (‘Optimizing Java bytecodes’ by Michał Cierniak an Wei Li; ‘Optimizing Java: theory and practice’ by Zoran Budimlic and Ken Kennedy; ‘Technologies for ubiquitous supercomputing: a Java interface to the Nexus communication system’ by Ian Foster, George K. Thiruvathukal and Steven Tuecke) describe base Java technology from optimized compilation to linkage with communication infrastructure. The next two papers (‘Java simulations for physics education’ by Simeon Warner, Simon Catterall and Edward Lipson; ‘Using Java and JavaScript in the Virtual Programming Laboratory: a Web-based parallel programming environment’ by Kivanc Dincer and Geoffrey C. Fox) describe uses of Java in both science and computer science education. Then we have two papers (‘Java's role in distributed collaboration by Marina Chen and James Cowie’; ‘Java enabling collaborative education, health care, and computing’ by Lukasz Beca, Gang Cheng, Geoffrey C. Fox, Tomasz Jurga, Konrad Olszewski, Marek Podgorny, Piotr Sokolowski and Krzysztof Walczak) centred on the fascinating field of collaboration. The last six papers study the critical area of parallel and distributed computing in Java. These discuss world-wide computing (‘SuperWeb: research issues in Java-based global computing’ by Albert D. Alexandrov, Maximilian Ibel, Klaus E. Schauser and Chris J. Scheiman), large-scale software integration with Java servers (‘WebFlow – a visual programming paradigm for Web/Java based coarse grain distributed computing’ by Dimple Bhatia, Vanco Burzevski, Maja Camuseva, Geoffrey Fox, Wojtek Furmanski and Girish Premchandran) and mobility (‘Resource-aware metacomputing’ by Anurag Acharya, M. Ranganathan and Joel Saltz). These three distributed computing studies are contrasted with three on parallel computing: ‘Automatically exploiting implicit parallelism in Java’ by Aart J. C. Bik and Dennis B. Gannon on shared memory; ‘SPMD programming in Java’ by Susan Flynn Hummel, Ton Ngo and Harini Srinivasan on the SPMD style, and ‘Experiments with “HP Java”’ by Bryan Carpenter, Yuh-Jye Chang, Geoffrey Fox, Donald Leskiw and Xiaoming Li on classic distributed memory data parallelism. Currently, it appears that Java promises the computational scientist programming environments which have both attractive user interfaces and high-performance execution. An important purpose of the first workshop and the follow-up events is to get a broad input and study of the issues in this field so that we can guide the rapidly moving Java juggernaut to be maximally effective for scientific and engineering computation. © 1997 John Wiley & Sons, Ltd.     

Using Meta-Modelling and Graph Grammars to Create Modelling Environments

This paper presents the combined use of meta-modelling and graph grammars for the generation of visual modelling tools for simulation formalisms. In meta-modelling, formalisms are described at a meta-level. This information is used by a meta-model processor to generate modelling tools for the described formalisms. We combine meta-modelling with graph grammars to extend the model manipulation capabilities of the generated modelling tools, as we store (meta-)models as graphs, and thus, express model manipulations as graph grammars.We show the design and implementation of these concepts in AToM³ (A Tool for Multi-formalism, Meta-Modelling). As an example we will present a meta-model for Causal Block Diagrams and a graph grammar to generate OOCSMP code, a continuous simulation language which has a compiler able to generate Java applets from the simulations models.     

Secure execution of Java applets using a remote playground

Mobile code presents a number of threats to machines that execute it. We introduce an approach for protecting machines and the resources they hold from mobile code and describe a system based on our approach for protecting host machines from Java 1.1 applets. In our approach, each Java applet downloaded to the protected domain is rerouted to a dedicated machine (or set of machines), the playground, at which it is executed. Prior to execution, the applet is transformed to use the downloading user's Web browser as a graphics terminal for its input and output, and so the user has the illusion that the applet is running on his own machine. In reality, however, mobile code runs only in the sanitized environment of the playground, where user files cannot be mounted and from which only limited network connections are accepted by machines in the protected domain. Our playground thus provides a second level of defense against mobile code that circumvents language-based defenses. This paper presents the design and implementation of a playground for Java 1.1 applets and discusses extensions of it for other forms of mobile code, including Java 1.2     

Real-time collaboration of virtual laboratories through the Internet

Web-based learning environments are becoming increasingly popular in higher education. One of the most important web-learning resources is the virtual laboratory (VL), which gives students an easy way for training and learning through the Internet. Moreover, on-line collaborative communication represents a practical method to transmit the knowledge and experience from the teacher to students overcoming physical distance and isolation. Considering these facts, the authors of this document have developed a new dynamic collaborative e-learning system which combines the main advantages of virtual laboratories and collaborative learning practices. In this system, the virtual laboratories are based on Java applets which have embedded simulations developed in Easy Java Simulations (EJS), an open-source tool for teachers who do not need complex programming skills. The collaborative e-learning is based on a real-time synchronized communication among these Java applets. Therefore, this original approach provides a new tool which integrates virtual laboratories inside a synchronous collaborative e-learning framework. This paper describes the main features of this system and its successful application in a distance education environment among different universities from Spain.     

WebFlow – a visual programming paradigm for Web/Java based coarse grain distributed computing

We present here recent work at NPAC aimed at developing WebFlow – a general purpose Web-based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We view WebFlow/WEbVM as a promising programming paradigm and co-ordination model for the exploding volume of Web/Java software, and we illustrate it in a set of ongoing application development activities. © 1997 John Wiley & Sons, Ltd.     

A web-based Internet Java Phone for real-time voice communication

Although a wide range of Internet telephony applications such as VocalTec's Internet Phone and Microsoft's NetMeeting has been developed to support real-time voice communication over the Internet, they are predominantly written for the Windows 95/NT platform and are not compatible with other operating systems. Moreover, most of the Internet telephony software is operated as stand-alone applications and must be downloaded and installed prior to operation. This has caused great inconvenience in using Internet telephony software. To resolve this, a web-based Internet Java Phone (or IJPhone) which can be downloaded from the Internet and run from standard Java-compliant web browser, is proposed in this paper. The IJPhone system consists of two main components: the Web-based Telephone Exchange for user connection and Internet Java Phone Applet for establishing real-time Internet voice communication. In addition, as Java applets have certain security restrictions placed on them, the paper also discusses the method proposed to overcome them. This revised version was published online in August 2006 with corrections to the Cover Date.     

Implementation of Java card Virtual Machine

Java card is a new system for programming smart cards,which is based on the Java language and Virtual Machine,Java card programs(applets)run in Java Card Runtime Environment (JCRE)including the java Card Virtual Machine(JCVM),the framework,the assoicated native methods and the API(Application Programming Interface),JCVM is implemented as two separate pieces: off-card VM(Virtual Machine)and on-card VM.The stack model and heap memory structure used by on-car VM and exception handling are introduced.Because there are limited resources wihin smart card environment,and garbage collection is not supported in JCVM,the preferred way to exception handling does not directly involve the use of throw,although the throw keyowrd is supported.Security is the most important feature of smart card.The Java Card applet security feature is also discussed.     

Applications of mobile agents and ambassadors in distributed simulation

This paper describes part of a project to investigate various uses of mobile agents within distributed simulations. A number of generic roles for these agents are suggested. The design of a monitoring facility for remote models is covered in detail. This has been constructed as an example of an “Ambassador system”, having a convenient sub-set of the facilities of a fully autonomous mobile agent system. The prototype of this system uses Java applets to provide model-specific controls and displays through a standard Internet browser interface.     

Bytecode verification on Java smart cards

This article presents a novel approach to the problem of bytecode verification for Java Card applets. By relying on prior off‐card bytecode transformations, we simplify the bytecode verifier and reduce its memory requirements to the point where it can be embedded on a smart card, thus increasing significantly the security of post‐issuance downloading of applets on Java Cards. This article describes the on‐card verification algorithm and the off‐card code transformations, and evaluates experimentally their impact on applet code size. Copyright © 2002 John Wiley & Sons, Ltd.     

基于WWW的仿真软件JRTSS

基于ＷＷＷ的仿真软件ＪＲＴＳＳ（Ｊａｖａ－ｂａｓｅｄＲｅａｌＴｉｍｅＳｙｓｔｅｍＳｉｍｕｌａｔｏｒ）以ＲＴＳＳ仿真软件为基础,保持其原有特色,并采用Ｊａｖａ为编程语言,运行在Ｂｒｏｗｓｅｒ／Ｓｅｒｖｅｒ环境下。ＪＲＴＳＳ软件由三部分组成：仿真核心、建模程序与结果后处理程序。其中仿真核心运行在Ｓｅｒｖｅｒ端,建模和结果后处理程序为ＪａｖａＡｐｐｌｅｔ,由用户的Ｂｒｏｗｓｅｒ下载并执行。ＪＲＴＳＳ的系统模型是一个开放队列网络。通过在不同抽象层次对多个数据采集与处理系统、通信网络以及柔性制造系统的仿真与性能评价,证实ＪＲＴＳＳ是一个用于系统开发的有力工具。     

An accelerator design for speedup of Java execution in consumer mobile devices

In today’s consumer electronics market, Java has become one of the most important programming languages for the rapid development of mobile applications – spanning from home appliances/controllers, mobile and communication devices, to network-centric applets. However, the demand for high-performance low-power Java-based consumer mobile applications puts forward new challenges to the system design and implementation. This paper analyzes the energy consumption, execution efficiency, and speed issues of Java applications in a typical consumer mobile device environment. By adopting a hardware-assisted approach, we introduce a Java accelerator with a companion Java virtual machine. The accelerator is designed in an asynchronous style, and can be integrated with most existing processors and operating systems. The core architecture, design philosophy, and implementation considerations are presented in detail in this paper.     

New threats of Java viruses

Only two Java viruses are known and have been published as a proof-of-concept: StrangeBrew and BeanHive. Since then the Java programming language has matured and greatly evolved to include a large number of new, sophisticated functionalities. At the same time, no serious study has been conducted to assess the potential viral risk attached to the new Java language. The potential threats have not really been explored yet. This article presents the state-of-the-art of Java viral capabilities and identifies some new techniques specific to the Java features that could be efficiently used by an attacker to spread malicious codes by means of Java classes. While this paper primarily focuses on targeting Java applications and not applets, the latter case will nonetheless be addressed among the different ways an actual attack could be launched by means of Java malicious codes. The protection and cure against such codes are also considered, dealing with the analysis of these programs at the bytecode level     

基于JAVA平台的移动代码安全性探讨

该文对Java平台中Applet安全性方面的问题,从1.0版本至今的发展过程进行了讨论。详细讨论了Java2平台对移动代码安全性的解决方案及Java6.0平台安全性的增强,对于在java平台下进行移动代码开发有一定指导意义。