专业英语论文-Java Ring
介绍java英语作文

介绍java英语作文English:Java is a general-purpose, high-level programming language that is designed to have as few implementation dependencies as possible. It is a class-based, object-oriented language that is similar to C++ but has a simpler syntax and automatic memory management. Java is a portable language, meaning that code written in Java can be run on any platform that has a Java Virtual Machine (JVM) installed.Java is a popular language for developing a wide range of applications, including web applications, desktop applications, and mobile applications. It is also used for developing enterprise software, such as databases, servers, and middleware. Java is a versatile language that can be used for a variety of purposes, making it a good choice for developers of all levels.中文。
Java是一种通用的高级编程语言,旨在尽可能减少实现依赖性。
用英语介绍java作文

用英语介绍java作文英文回答:Java is a high-level, object-oriented programming language used to develop a wide range of software applications. It is known for its platform independence, which allows programs written in Java to run on any operating system or hardware platform that supports the Java Virtual Machine (JVM).Java was developed by Sun Microsystems in 1995 and is now owned by Oracle Corporation. It is one of the most popular programming languages in use today, and is used by millions of developers worldwide.Java is known for its robustness, security, and ease of development. It is also very versatile, and can be used to develop a wide range of applications, including:Enterprise applications.Web applications.Mobile applications.Desktop applications.Embedded systems.Java is a strongly typed language, which means that the data type of each variable is known at compile time. This helps to prevent errors and makes Java code more reliable.Java is also an object-oriented language, which means that it uses objects to represent real-world entities. This makes Java code more modular and easier to maintain.Java is a very powerful language, and it can be used to develop a wide range of software applications. It is a great choice for developers who are looking for a language that is robust, secure, and easy to develop.中文回答:Java是一种高级面向对象的编程语言,可以用来开发广泛的软件应用。
JAVA 技术英语文献

Java and the InternetIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn’t immediately obvious if you’re coming from a traditional programming perspective. Although Java is very useful for solving traditional standalone programming problems, it is also important because it will solve programming problems on the World Wide Web.What is the Web?The Web can seem a bit of a mystery at first, with all this talk of “surfing,” “presence,” and “home pages.” It’s helpful to step back and see what it really is, but to do this you must understand client/server systems, another aspect of computing that’s full of confusing issues.Client/Server computingThe primary idea of a client/server system is that you have a central repository of information—some kind of data, often in a database—that you want to distribute on demand to some set of people or machines. A key to theclient/server concept is that the repository of information is centrally located so that it can be changed and so that those changes will propagate out to the information consumers. Taken together, the information repository, the software that distributes the information, and the machine(s) where the information and software reside is called the server. The software that resides on the remote machine, communicates with the server, fetches the information, processes it, and then displays it on the remote machine is called the client.The basic concept of client/server computing, then, is not so complicated. The problems arise because you have a single server trying to serve many clients at once. Generally, a database management system is involved, so the designer “balances” the layout of data into tables for optimal use. In addition, systems often allow a client to insert new information into a server. This means you must ensure that one cl ient’s new data doesn’t walk over another client’s new data, or that data isn’t lost in the process of adding it to the database (this is called transaction processing). As client software changes, it must be built, debugged, and installed on the client machines, which turns out to be more complicated and expensive than you might think. It’s especially problematic to support multiple types of computers and operating systems. Finally, there’s the all-important performance issue: You might have hundredsof clients making requests of your server at any one time, so any small delay is crucial. To minimize latency, programmers work hard to offload processing tasks, often to the client machine, but sometimes to other machines at the server site, using so-called middleware. (Middleware is also used to improve maintainability.)The simple idea of distributing information has so many layers of complexity that the whole problem can seem hopelessly enigmatic. And yet it’s crucial: Client/server computing accounts for roughly half of all programming activities. It’s responsible for everything from taking orders and credit-card transactions to the distribution of any kind of data—stock market, scientific, government, you name it. What we’ve come up with in the past is ind ividual solutions to individual problems, inventing a new solution each time. These were hard to create and hard to use, and the user had to learn a new interface for each one. The entire client/server problem needs to be solved in a big way.The Web as a giant serverThe Web is actually one giant client/server system. It’s a bit worse than that, since you have all the servers and clients coexisting on a single network at once. You don’t need to know that, because all you care about is connecting to and interacting with one server at a time (even though you might be hopping around the world in your search for the correct server).Initially it was a simple one-way process. You made a request of a server and it handed you a file, which your machine’s browser software (i.e., the client) would interpret by formatting onto your local machine. But in short order people began wanting to do more than just deliver pages from a server. They wanted full client/server capability so that the client could feed information back to the server, for example, to do database lookups on the server, to add new information to the server, or to place an order (which required more security than the original systems offered). These are the changes we’ve been seeing in the development of the Web.The Web browser was a big step forward: the concept that one piece of information could be displayed on any type of computer without change. However, browsers were still rather primitive and rapidly bogged down by the demands placed on them. They weren’t particularly interactive, and tended to clog up both the server and the Internet because any time you needed to do something that required programming you had to send information back to the server to be processed. It could take many seconds or minutes to find out you had misspelled something in your request. Since the browser was just a viewer it couldn’t perform even the simplest computing tasks. (On the otherhand, it was safe, because it couldn’t execute any programs on your local machine that might contain bugs or viruses.)To solve this problem, different approaches have been taken. To begin with, graphics standards have been enhanced to allow better animation and video within browsers. The remainder of the problem can be solved only by incorporating the ability to run programs on the client end, under the browser. This is called client-side programming.Client-side programmingThe Web’s initial server-browser design provided for interactive content, but the interactivity was completely provided by the server. The server produced static pages for the client browser, which would simply interpret and display them. Basic HyperText Markup Language (HTML) contains simple mechanisms for data gathering: text-entry boxes, check boxes, radio boxes, lists and drop-down lists, as well as a button that can only be programmed to reset the data on the form or “submit” the data on the form back to the server. This submission passes through the Common Gateway Interface (CGI) provided on all Web servers. The text within the submission tells CGI what to do with it. The most common action is to run a program located on the server in a directory that’s typically called “cgi-bin.” (If you watch the address window at the top of your browser when you push a button on a Web page, you can sometimes see “cgi-bin” within all the gobbledygook there.) These programs can be written in most languages. Perl has been a common choice because it is designed for text manipulation and is interpreted, so it can be installed on any server regardless of processor or operating system. However, Python (my favorite—see ) has been making inroads because of its greater power and simplicity.Many powerful Web sites today are built strictly on CGI, and you can in factdo nearly anything with CGI. However, Web sites built on CGI programs can rapidly become overly complicated to maintain, and there is also the problem of response time. The response of a CGI program depends on how much data must be sent, as well as the load on both the server and the Internet. (On topof this, starting a CGI program tends to be slow.) The initial designers of the Web did not foresee how rapidly this bandwidth would be exhausted for the kinds of applications people developed. For example, any sort of dynamic graphing is nearly impossible to perform with consistency because a Graphics Interchange Format (GIF) file must be created and moved from the server to the client for each version of the graph. And you’ve no doubt had direct experience with something as simple as validating the data on an input form. You press the submit button on a page; the data is shipped back to the server; the server starts a CGI program that discovers an error, formats an HTMLpage informing you of the error, and then sends the page back to you; you must then back up a page and try again. Not only is this slow, it’s inelegant.The solution is client-side programming. Most machines that run Web browsers are powerful engines capable of doing vast work, and with the original static HTML approach they are sitting there, just idly waiting for the server to dish up the next page. Client-side programming means that the Web browser is harnessed to do whatever work it can, and the result for the user is a much speedier and more interactive experience at your Web site.The problem with discussions of client-side programming is that they aren’t very different from discussions of programming in general. The parameters are almost the same, but the platform is different; a Web browser is like a limited operating system. In the end, you must still program, and this accounts for the dizzying array of problems and solutions produced byclient-side programming. The rest of this section provides an overview of the issues and approaches in client-side programming.Plug-insOne of the most significant steps forward in client-side programming is the development of the plug-in. This is a way for a programmer to add new functionality to the browser by downloading a piece of code that plugs itself into the appropriate spot in the browser. It tells the browser “from now on you can perform this new activity.” (You need to download the plug-in only once.) Some fast and powerful behavior is added to browsers via plug-ins, but writing a plug-in is not a trivial task, and isn’t something you’d want to do as part of the process of building a particular site. The value of the plug-in for client-side programming is that it allows an expert programmer to develop a new language and add that language to a browser without the permission of the browser manufacturer. Thus, plug-ins provide a “back door” that allows the creation of new client-side programming languages (although not all languages are implemented as plug-ins).Scripting languagesPlug-ins resulted in an explosion of scripting languages. With a scripting language, you embed the source code for your client-side program directly into the HTML page, and the plug-in that interprets that language is automatically activated while the HTML page is being displayed. Scripting languages tend to be reasonably easy to understand and, because they are simply text that is part of an HTML page, they load very quickly as part of the single server hit required to procure that page. The trade-off is that your codeis exp osed for everyone to see (and steal). Generally, however, you aren’t doing amazingly sophisticated things with scripting languages, so this is not too much of a hardship.This points out that the scripting languages used inside Web browsers are really intended to solve specific types of problems, primarily the creation of richer and more interactive graphical user interfaces (GUIs). However, a scripting language might solve 80 percent of the problems encountered in client-side programming. Your problems might very well fit completely within that 80 percent, and since scripting languages can allow easier and faster development, you should probably consider a scripting language before looking at a more involved solution such as Java or ActiveX programming. The most commonly discussed browser scripting languages are JavaScript (which has nothing to do with Java; it’s named that way just to grab some of Java’s marketing momentum), VBScript (which looks like Visual BASIC), and Tcl/Tk, which comes from the popular cross-platform GUI-building language. There are others out there, and no doubt more in development.JavaScript is probably the most commonly supported. It comes built into both Netscape Navigator and the Microsoft Internet Explorer (IE). Unfortunately, the flavor of JavaScript on the two browsers can vary widely (the Mozilla browser, freely downloadable from , supports the ECMAScript standard, which may one day become universally supported). In addition, there are probably more JavaScript books available than there arefor the other browser languages, and some tools automatically create pages using JavaScript. However, if you’re already fluent in Visual BASIC or Tcl/Tk, you’ll be more productive using those scripting languages rather than l earning a new one. (You’ll have your hands full dealing with the Web issues already.)JavaIf a scripting language can solve 80 percent of the client-side programming problems, what about the other 20 percent—the “really hard stuff?” Java is a popular solution for this. Not only is it a powerful programming languagebuilt to be secure, cross-platform, and international, but Java is being continually extended to provide language features and libraries that elegantly handle problems that are difficult in traditional programming languages, such as multithreading, database access, network programming, and distributed computing. Java allows client-side programming via the applet and with Java Web Start.An applet is a mini-program that will run only under a Web browser. The applet is downloaded automatically as part of a Web page (just as, for example,a graphic is automatically downloaded). When the applet is activated, it executes a program. This is part of its beauty—it provides you with a way to automatically distribute the client software from the server at the time the user needs the client software, and no sooner. The user gets the latest version of the client software without fail and without difficult reinstallation. Because of the way Java is designed, the programmer needs to create only a single program, and that program automatically works with all computers that have browsers with built-in Java interpreters. (This safely includes the vast majority of machines.) Since Java is a full-fledged programming language, you can do as much work as possible on the client before and after making requests of the server. For example, you won’t need to send a request form across the Internet to discover that you’ve gotten a date or some other parameter wrong, and your client computer can quickly do the work of plotting data instead of waiting for the server to make a plot and ship a graphic image back to you. Not only do you get the immediate win of speed and responsiveness, but the general network traffic and load on servers can be reduced, preventing the entire Internet from slowing down.One advantage a Java applet has over a scripted program is that it’s in compiled form, so the source code isn’t available to the client. On the other hand, a Java applet can be decompiled without too much trouble, but hiding your code is often not an important issue. Two other factors can be important. As you will see later in this book, a compiled Java applet can require extra time to download, if it is large. A scripted program will just be integrated into the Web page as part of its text (and will generally be smaller and reduce server hits). This could be important to the responsiveness of your Web site. Another factor is the all-important learning curve. Regardless of what you’v e heard, Java is not a trivial language to learn. If you’re a VISUAL BASIC programmer, moving to VBScript will be your fastest solution (assuming you can constrain your customers to Windows platforms), and since it will probably solve most typical client/server problems, you might be hard pressed to justify learning Java. If you’re experienced with a scripting language you will certainly benefit from looking at JavaScript or VBScript before committing to Java, because they might fit your needs handily and y ou’ll be more productive sooner..NET and C#For awhile, the main competitor to Java applets was Microsoft’s ActiveX, although it required that the client be running Windows. Since then, Microsoft has produced a full competitor to Java in the form of the .NET platform and the C# programming language. The .NET platform is roughly the same as the Java virtual machine and Java libraries, and C# bears unmistakable similarities to Java. This is certainly the best work that Microsoft has done inthe arena of programming languages and programming environments. Of course, they had the considerable advantage of being able to see what worked well and what didn’t work so well in Java, and build upon that, but build they have. This is the first time since its inception that Java has had any real competition, and if all goes well, the result will be that the Java designers at Sun will take a hard look at C# and why programmers might want to move to it, and will respond by making fundamental improvements to Java. Currently, the main vulnerability and important question concerning .NET is whether Microsoft will allow it to be completely ported to other platforms. They claim there’s no problem doing this, and the Mono project() has a partial implementation of .NET working on Linux, but until the implementation is complete and Microsoft has not decided to squash any part of it, .NET as a cross-platform solution is still a risky bet.To learn more about .NET and C#, see Thinking in C#by Larry O’Brien and Bruce l, Prentice Hall 2003.SecurityAutomatically downloading and running programs across the Internet can sound like a virus-builder’s dream. If you click on a Web site, you might automatically download any number of things along with the HTML page: GIF files, script code, compiled Java code, and ActiveX components. Some of these are benign; GIF files can’t do any harm, and scripting languages are generally limited in what they can do. Java was also designed to run its applets within a “sandbox” of safety, w hich prevents it from writing to disk or accessing memory outside the sandbox.Microsoft’s ActiveX is at the opposite end of the spectrum. Programming with ActiveX is like programming Windows—you can do anything you want. So if you click on a page that downloads an ActiveX component, that component might cause damage to the files on your disk. Of course, programs that you load onto your computer that are not restricted to running inside a Web browser can do the same thing. Viruses downloaded from Bulletin-Board Systems (BBSs) have long been .The solution seems to be “digital signatures,” whereby code is verified to show who the author is. This is based on the idea that a virus works because its creator can be anonymous, so if you remove the anonymity, individuals will be forced to be responsible for their actions. This seems like a good plan because it allows programs to be much more functional, and I suspect it will eliminate malicious mischief. If, however, a program has an unintentional destructive bug, it will still cause problems.The Java approach is to prevent these problems from occurring, via the sandbox. The Java interpreter that lives on your local Web browser examines the applet for any untoward instructions as the applet is being loaded. In particular, the applet cannot write files to disk or erase files (one of the mainstays of viruses). Applets are generally considered to be safe, and since this is essential for reliable client/server systems, any bugs in the Java language that allow viruses a re rapidly repaired. (It’s worth noting that the browser software actually enforces these security restrictions, and some browsers allow you to select different security levels to provide varying degrees of access to your system.)You might be skeptical of this rather draconian restriction against writing files to your local disk. For example, you may want to build a local database or save data for later use offline. The initial vision seemed to be that eventually everyone would get online to do anything important, but that was soon seen to be impractical (although low-cost “Internet appliances” might someday satisfy the needs of a significant segment of users). The solution is the “signed applet” that uses public-key encryption to verify that an applet does indeed come from where it claims it does. A signed applet can still trash your disk, but the theory is that since you can now hold the applet creators accountable, they won’t do vicious things. Java provides a framework for digital signatures so that youwill eventually be able to allow an applet to step outside the sandbox if necessary. Chapter 14 contains an example of how to sign an applet.In addition, Java Web Start is a relatively new way to easily distribute standalone programs that don’t need a w eb browser in which to run. This technology has the potential of solving many client side problems associated with running programs inside a browser. Web Start programs can either be signed, or they can ask the client for permission every time they are doing something potentially dangerous on the local system. Chapter 14 has a simple example and explanation of Java Web Start.Digital signatures have missed an important issue, which is the speed that people move around on the Internet. If you download a buggy program and it does something untoward, how long will it be before you discover the damage? It could be days or even weeks. By then, how will you track down the program that’s done it? And what good will it do you at that point?Internet vs. intranetThe Web is the most general solution to the client/server problem, so it makes sense to use the same technology to solve a subset of the problem, in particular the classic client/server problem within a company. With traditional client/server approaches you have the problem of multiple types ofclient computers, as well as the difficulty of installing new client software, both of which are handily solved with Web browsers and client-side programming. When Web technology is used for an information network that is restricted to a particular company, it is referred to as an intranet. Intranets provide much greater security than the Internet, since you can physically control access to the servers within your company. In terms of training, it seems that once peopl e understand the general concept of a browser it’s much easier for them to deal with differences in the way pages and applets look, so the learning curve for new kinds of systems seems to be reduced.The security problem brings us to one of the divisions that seems to be automatically forming in the world of client-side programming. If your program is running on the Internet, you don’t know what platform it will be working under, and you want to be extra careful that you don’t disseminate buggy code. You need something cross-platform and secure, like a scripting language or Java.If you’re running on an intranet, you might have a different set of constraints. It’s not uncommon that your machines could all be Intel/Windows platforms. On an intranet, you’re responsible for the quality of your own code and can repair bugs when they’re discovered. In addition, you might already have a body of legacy code that you’ve been using in a more traditional client/server approach, whereby you must physically install client programs every time you do an upgrade. The time wasted in installing upgrades is the most compelling reason to move to browsers, because upgrades are invisible and automatic (Java Web Start is also a solution to this problem). If you are involved in such an intranet, the most sensible approach to take is the shortest path that allows you to use your existing code base, rather than trying to recode your programs in a new language.When faced with this bewildering array of solutions to the client-side programming problem, the best plan of attack is a cost-benefit analysis. Consider the constraints of your problem and what would be the shortest path to your solution. Since client-side programming is still programming, it’s always a good idea to take the fastest development approach for your particular situation. This is an aggressive stance to prepare for inevitable encounters with the problems of program development.Server-side programmingThis whole discussion has ignored the issue of server-side programming. What happens when you make a request of a server? Most of the time the request is simply “send me this file.” Your browser then interprets the file in some appropriate fashion: as an HTML page, a graphic image, a Java applet, a script program, etc. A more complicated request to a server generally involvesa database transaction. A common scenario involves a request for a complex database search, which the server then formats into an HTML page and sends to you as the result. (Of course, if the client has more intelligence via Java or a scripting language, the raw data can be sent and formatted at the client end, which will be faster and less load on the server.) Or you might want to register your name in a database when you join a group or place an order, which will involve changes to that database. These database requests must be processed via some code on the server side, which is generally referred to as server-side programming. Traditionally, server-side programming has been performed using Perl, Python, C++, or some other language, to create CGI programs, but more sophisticated systems have been appearing. These include Java-based Web servers that allow you to perform all your server-side programming in Java by writing what are called servlets. Servlets and their offspring, JSPs, are two of the most compelling reasons that companies who develop Web sites are moving to Java, especially because they eliminate the problems of dealing with differently-abled browsers (these topics are covered in Thinking in Enterprise Java)Java和因特网既然Java不过另一种类型的程序设计语言,大家可能会奇怪它为什么值得如此重视,为什么还有这么多的人认为它是计算机程序设计的一个里程碑呢?如果您来自一个传统的程序设计背景,那么答案在刚开始的时候并不是很明显。
2021年java编程英文参考文献

一、IntroductionJava programming language is one of the most widely used and popular programming languages in the world. Since its initial release in 1995, Java has g本人ned widespread adoption in various fields and industries, including web development, mobile application development, enterprise software development, and scientificputing. As a result, there is a large body of literature and reference materials av本人lable for Java programming, providing valuable insights, best practices, and solutions tomon challenges.二、Java Language SpecificationThe Java Language Specification (JLS) is the official reference guide for the Java programming language, providing a det本人led andprehensive overview of the language syntax, semantics, and core libraries. Written by the language designers themselves, the JLS serves as the authoritative source for understanding the intricacies of Java, including its object-oriented features, data types, control structures, and exception handling. The latest version of the JLS, for Java 17, is av本人lable online for free and is an essential resource for any serious Java programmer.三、Effective Java by Joshua BlochEffective Java, written by Joshua Bloch, is a widely accl本人med book that provides practical guidance and best practices for writing high-quality, efficient, and m本人nt本人nable Java code. The book covers a wide range of topics, including object creation, method design, concurrency, and serialization, offering valuable insights and rmendations based on Bloch's extensive experience as a Java architect at Sun Microsystems and Google. With its clear and concise explanations, as well as numerous code examples, Effective Java is an indispensable resource for both novice and experienced Java developers.四、Java Concurrency in Practice by Brian Goetz et al. Concurrency is a crucial aspect of modern software development, and Java provides powerful features for writing concurrent programs. Java Concurrency in Practice, authored by Brian Goetz and his colleagues, offers aprehensive and in-depth exploration of the Java platform's concurrency utilities, threading models, and best practices for writing concurrent and parallel code. The book also covers advanced topics such as synchronization, thread safety, and performance optimization, making it a valuable reference for developers working on multi-threaded applications.五、Head First Design Patterns by Eric Freeman et al.Design patterns are essential tools for tacklingmon software design challenges, and Head First Design Patterns presents an engaging and accessible introduction to the topic. Written by Eric Freeman, Elisabeth Robson, Bert Bates, and Kathy Sierra, the book uses a unique and interactive approach to convey fundamental design principles and a variety of design patterns in an easy-to-understand manner. With its visually rich and structured content, Head First Design Patterns is highly rmended for Java developers who want to improve their software design skills and apply proven solutions to recurring design problems.六、Java Performance: The Definitive Guide by Scott Oaks Performance optimization is a critical aspect of software development, particularly in the context of modern, resource-intensive applications. Java Performance: The Definitive Guide, authored by Scott Oaks, is aprehensive and authoritative resource for understanding, measuring, and improving the performance of Java applications. The book covers a wide range of topics, including JVM internals, garbage collection, profiling, and tuning, and provides practical guidance and real-worldexamples for achieving optimal performance in Java-based systems.七、ConclusionIn conclusion, the Java programming language offers a rich ecosystem of reference materials, books, and documentation to support developers in their Java programming journey. Whether it's mastering the language syntax and core libraries, adopting best practices for writing high-quality code, or delving into advanced topics such as concurrency, design patterns, and performance optimization, there are numerous resources av本人lable to cater to the diverse needs and interests of Java developers. By leveraging these reference materials, developers can enhance their skills, stay updated with the latest industry trends, and build robust and efficient software solutions using Java.。
关于java的英文作文

关于java的英文作文英文:Java is a popular programming language that is used in a variety of applications. It is an object-oriented language that was created in the mid-1990s by James Gosling at Sun Microsystems. Java is known for its portability, which means that it can run on different platforms without any modifications to the code.One of the reasons why I like Java is because of its versatility. It can be used for developing desktop applications, web applications, mobile applications, and even games. For example, I have used Java to develop a mobile application that helps users track their fitness goals. The app uses Java to communicate with a backend server and store data in a database.Another reason why I like Java is because of its rich library of classes and functions. Java has a vastcollection of built-in classes that can be used to perform various tasks. For example, the java.util package contains classes for working with dates, times, and collections. The package contains classes for working with network connections and protocols.In addition to its versatility and rich library, Javais also known for its security features. Java has a built-in security manager that can prevent malicious code from running on a system. This is particularly important for web applications, where security is a major concern.Overall, Java is a powerful and versatile programming language that can be used for a wide range of applications. Whether you are developing a desktop application, web application, or mobile application, Java has the tools and resources you need to get the job done.中文:Java是一种流行的编程语言,被广泛应用于各种应用程序中。
java的用途英语作文

java的用途英语作文Java, a programming language that revolutionized the software industry, has emerged as a leading force intoday's digital world. Its widespread adoption and adaptability across various platforms and applications are testament to its versatility and reliability. From desktop applications to web development, mobile computing, and beyond, Java's impact is felt across the technological spectrum.**Desktop Applications**Java's early foray into the computing world was through desktop applications. Its "Write Once, Run Anywhere" mantra allowed developers to create cross-platform softwarewithout the need for separate codebases for each operating system. This eliminated the complexity and cost associated with maintaining multiple versions of the same application. Java-based desktop applications are still widely used today, ranging from productivity tools to gaming platforms.**Web Development**With the advent of the internet, Java found a new home in web development. Servlets and JavaServer Pages (JSP) revolutionized web application development by providing a platform-independent, scalable, and secure way to create dynamic web content. Java-based web frameworks like Spring and Struts have further simplified the development process, making it easier for developers to build robust and scalable web applications.**Mobile Computing**As mobile computing gained popularity, Java made its way into the mobile space with the launch of Java ME (Micro Edition) for mobile devices. This allowed developers to create applications that could run on a wide range of mobile phones, regardless of their hardware or operating system. Although Java's market share in mobile development has been overshadowed by other languages like Swift and Kotlin, it still holds a significant presence inenterprise-level mobile solutions.**Big Data and Cloud Computing**In recent years, Java has emerged as a key player in big data and cloud computing. Its scalability, performance,and robust security features make it an ideal choice for handling massive amounts of data in distributed environments. Hadoop, a popular open-source framework for processing large datasets, is written in Java. Additionally, Java-based platforms like Apache Spark and Kafka provide powerful tools for real-time data processing and streaming analytics.**Enterprise Solutions**Java's strength in enterprise solutions lies in its ability to handle complex, mission-critical applications. Enterprises worldwide rely on Java-based systems for their enterprise resource planning (ERP), customer relationship management (CRM), and supply chain management (SCM) needs. The language's robust security features, scalability, and support for distributed computing make it a natural fit for these demanding enterprise environments.**The Future of Java**As the technological landscape continues to evolve,Java remains a relevant and influential force. With the advent of new frameworks, libraries, and tools, Java developers are constantly innovating and pushing theboundaries of what's possible with the language. From machine learning and artificial intelligence to the Internet of Things (IoT) and beyond, Java's future looks bright as it continues to power the digital world.**Java的用途:技术之旅**Java,一种改变了软件行业的编程语言,如今已成为当今数字世界中的领先力量。
java程序设计实践报告2000字

java程序设计实践报告2000字(中英文实用版)英文文档:Java Programming Practice Report - 2000 WordsIntroduction:This report aims to document my practical experience in Java programming.Over the course of several weeks, I have engaged in various coding exercises and projects to enhance my skills and understanding of Java.The following report will outline the key concepts learned, challenges faced, and insights gained during this practice period.1.Basic Syntax and Concepts:To begin my Java journey, I familiarized myself with the basic syntax and concepts of the language.This included understanding variables, data types, conditional statements, loops, and functions.I practiced writing simple programs to reinforce these concepts and gradually moved on to more complex scenarios.2.Object-Oriented Programming:Java is a firmly typed, object-oriented language, which emphasizes the use of classes and objects.I explored the principles of encapsulation, inheritance, and polymorphism through various examples.I implemented classes, defined methods, and constructed objects to gain a deeper understanding of object-oriented programming principles.3.Data Structures and Algorithms:To enhance my problem-solving skills, I focused on learning different data structures and algorithms.I studied arrays, linked lists, stacks, queues, trees, and graphs.I implemented various sorting and searching algorithms, such as bubble sort, insertion sort, selection sort, and binary search.These exercises helped me improve my ability to analyze and optimize code for efficiency and performance.4.File Handling:File handling is a crucial aspect of programming, and Java provides robust libraries for working with files and directories.I learned how to read from and write to files using classes like FileReader, FileWriter, and BufferedReader.I practiced implementing file handling in different scenarios, such as reading input from a text file or writing output to a log file.5.Exception Handling:Exception handling is essential for writing robust and error-free code.In Java, exceptions are classified into checked and unchecked exceptions.I learned how to handle checked exceptions using try-catch blocks and声明throws 关键字.I also explored the use of finally blocks and exception chaining to ensure proper resource management and error handling.6.Java Libraries and Frameworks:Java has a vast ecosystem of libraries and frameworks that simplify development.I became familiar with popular libraries like Apache Commons, JavaMail, and JSON.I also delved into frameworks like Spring and Hibernate, which provide powerful tools for building enterprise-level applications.7.Debugging and Code Optimization:To improve my coding skills, I focused on debugging and code optimization.I utilized integrated development environments (IDEs) like Eclipse and IntelliJ IDEA to identify and fix errors in my code.I also learned various techniques for optimizing code, such as minimizing redundant code, using appropriate data structures, and leveraging built-in Java libraries.Conclusion:Throughout this Java programming practice report, I have highlighted my journey of learning and implementing various Java concepts.From basic syntax to advanced techniques, this practice period has significantly enhanced my understanding of Java programming.I have gained practical experience, overcome challenges, and acquired valuable insights that will undoubtedly aid me in my future Java development endeavors.中文文档:Java编程实践报告——2000字引言:本报告旨在记录我在Java编程实践中的经验。
java毕业设计外文文献原文及译文

毕业设计说明书英文文献及中文翻译学学 院:专指导教师:2014 年 6 月软件学院 软件工程Thinking in JavaAlthough it is based on C++, Java is more of a “pure” object-oriented C++ and Java are hybrid languages, but in Java the designers felt that the hybridization was not as important as it was in C++. A hybrid language allows multiple programming styles; the reason C++ is hybrid is to support backward compatibility with the C language. Because C++ is a superset of the C language, it includes many of that language’s undesirable features, which can make some aspects of C++ overly complicated. The Java language assumes that you want to do only object-oriented programming. This means that before you can begin you must shift your mindset into an object-oriented world (unless it’s already there). The benefit of this initial effort is the ability to program in a language that is simpler to learn and to use than many other OOP languages. In this chapter we’ll see the basic components of a Java program and we’ll learn that everything in Java is an object, even a Java program.Each programming language has its own means of manipulating data. Sometimes the programmer must be constantly aware of what type of manipulation is going on. Are you manipulating the object directly, or are you dealing with some kind of indirect representation (a pointer in C or C++) that must be treated with a special syntax?All this is simplified in Java. You treat everything as an object, using a single consistent syntax. Although you treat everything as an object, the identifier you manipulate is actually a “reference” to an object. You might imagine this scene as a television (the object) with your remote control (the reference). As long as you’re holding this reference, you have a connection to the television, but when someone says “change the channel” or “lower the volume,” what you’re manipulating is the reference, which in turn modifies the object. If you want to move around the room and still control the television, you take the remote/reference with you, not the television.Also, the remote control can stand on its own, with no television. That is, just because you have a reference doesn’t mean there’s necessarily an object connected to it. So if you want to hold a word or sentence, you create a String reference:But here you’ve created only the reference, not an object. If you decided to send a message to s at this point, you’ll get an error (at run time) because s isn’t actually attached to anything (there’s no television). A safer practice, then, is always to initialize a reference when you create it.However, this uses a special Java feature: strings can be initialized with quoted text. Normally, you must use a more general type of initialization for objectsWhen you create a reference, you want to connect it with a new object. You do so, in general, with the new keyword. The keyword new says, “Make me a new one of these objects.” So in the preceding example, you can say:Not only does this mean “Make me a new String,” but it also gives information about how to make the String by supplying an initial character string.Of course, String is not the only type that exists. Java comes with a plethora of ready-made types. What’s more important is that you can create your own types. In fact, that’s the fundamental activity in Java programming, and it’s what you’ll b e learning about in the rest of this bookIt’s useful to visualize some aspects of how things are laid out while the program is running—in particular how memory is arranged. There are six different places to store data: Registers. This is the fastest storage because it exists in a place different from that of other storage: inside the processor. However, the number of registers is severely limited, so registers are allocated by the compiler according to its needs. You don’t have direct control, nor do you see any evidence in your programs that registers even exist.The stack. This lives in the general random-access memory (RAM) area, but has direct support from the processor via its stack pointer. The stack pointer is moved down to create new memory and moved up to release that memory. This is an extremely fast and efficient way to allocate storage, second only to registers. The Java compiler must know, while it is creating the program, the exact size and lifetime of all the data that is stored on the stack, because it must generate the code to move the stack pointer up and down. This constraint places limits on the flexibility of your programs, so while some Java storage exists on the stack—in particular, object references—Java objects themselves are not placed on the stack. The heap. This is a general-purpose pool of memory (also in the RAM area) where all Java objects live. The nice thing about the heap is that, unlike the stack, the compiler doesn’t need to know how much storage it needs to allocate from the heap or how long that storage must stay on the heap. Thus, there’s a great deal of flexibility in using storage on the heap. Whenever you need to create an object, you simply write the code to create it by using new, and the storage is allocated on th e heap when that code is executed. Of course there’s a priceyou pay for this flexibility. It takes more time to allocate heap storage than it does to allocate stack storage (if you even could create objects on the stack in Java, as you can in C++). Static storage. “Static” is used here in the sense of “in a fixed location” (although it’s also in RAM). Static storage contains data that is available for the entire time a program is running. You can use the static keyword to specify that a particular element of an object is static, but Java objects themselves are never placed in static storage.Constant storage. Constant values are often placed directly in the program code, which is safe since they can never change. Sometimes constants are cordoned off by themselves so that they can be optionally placed in read-only memory (ROM), in embedded systems.Non-RAM storage. If data lives completely outside a program, it can exist while the program is not running, outside the control of the program. The two primary examples of this are streamed objects, in which objects are turned into streams of bytes, generally to be sent to another machine, and persistent objects, in which the objects are placed on disk so they will hold their state even when the program is terminated. The trick with these types of storage is turning the objects into something that can exist on the other medium, and yet can be resurrected into a regular RAM-based object when necessary. Java provides support for lightweight persistence, and future versions of Java might provide more complete solutions for persistenceOne group of types, which you’ll use quite often in your programming, gets special treatment. You can think of these as “primitive” types. The reason for the special treatment is that to create an object with new—especially a small, simple variable—isn’t very efficient, because new places objects on the heap. For these types Java falls back on the approach taken by C and C++. That is, instead of creating the variable by using new, an “automatic” variable is created that is not a reference. The variable holds the value, and it’s placed on the stack, so it’s much more efficient.Java determines the size of each primitive type. These sizes don’t change from one machine architecture to another as they do in most languages. This size invariance is one reason Java programs are portableJava编程思想“尽管以C++为基础,但Java是一种更纯粹的面向对象程序设计语言”。
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The Java RingYingqi.LeeGuangxi Normal University, Chinayingqi.lee@Abstract—A Java Ring is a finger ring that contains a small microprocessor with built-in capabilities for the user, a sort of smart card that is wearable on a finger.The Java Ring’s historical background. The Java Ring can be a wearable Computer, and keep your money safe.Keywords—Java Ring, history, background, effect, function.Ⅰ.WHAT IS THE JAV A RINGA Java Ring is a finger ring that contains a small microprocessor with built-in capabilities for theuser, a sort of smart card that is wearable on a finger. Sun Microsystem's Java Ring was introduced attheir Java One Conference in 1998 and, instead of a gemstone, contained an inexpensivemicroprocessor in a stainless-steel iButton running a Java V irtual Machine and preloaded with applets(little application programs). The rings Array were built by Dallas Semiconductor.The Java Ring is an extremelysecure Java-powered electronic tokenwith a continuously running, unalterablereal-time clock and rugged packaging,suitable for many applications. Thejewel of the Java Ring is the Java RingiButton – a 16 mm one-million transistor,single-chip trusted microcomputer with1.Java Ringa Java virtual machine (JVM) housed ina rugged and secure stainless-steel case.Designed to be fully compatible with the Java Card 2.0 standard the processor features a high –speed1024-bit modular exponentiator for RSA encryption, large RAM and ROM memory capacity, and anunalterable real-time clock. The packaged module has only a single electrical contact and a groundreturn, conforming to the specifications of the Dallas Semiconductor 1-Wire bus. Lithium-backednon-volatile SRAM offers high read/write speed and unparalleled tamper resistance throughnear-instantaneous clearing of all memory when tempering is detected, a feature known as rapidzeroization. Data integrity and clock function are maintained for more than 10 years. The 16-millimeterdiameter stainless steel enclosure accommodates the larger chip sizes needed for up to 128 kilobytes ofhigh-speed nonvolatile static RAM. The small and rugged packaging of the module allows it to attachto various accessories. (This is part of my introduction)Workstations at the conference had "ring readers" installed on them that downloaded informationabout the user from the conference registration system. This information was then used to enable a number of personalized services. For example, a robotic machine made coffee according to user preferences, which it downloaded when they snapped the ring into another "ring reader." (This is part of my introduction)Although Java Rings aren't widely used yet, such rings or similar devices could have a number of real-world applications, such as starting your car and having all your vehicle's components (such as the seat, mirrors, and radio selections) automatically adjust to your preferences.Ⅱ.HISTORICAL BA CKGROUNDIn the summer of 1989, Dallas Semiconductor Corp. produced the first stainless-steel-encapsulated memory devices utilizing the Dallas Semiconductor 1-Wire communication protocol. By 1990, this protocol had been refined and employed in a variety of self-contained memory devices. Originally called "touch memory" devices, they were later renamed "iButtons." Packaged like batteries, iButtons have only a single active electrical contact on the top surface, with the stainless steel shell serving as ground.Data can be read from or written to the memory serially through a simple and inexpensive RS232C serial port adapter, which also supplies the power required to perform the I/O. The iButton memory can be read or written with a momentary contact to the "Blue Dot" receptor provided by the adapter. When not connected to the serial port adapter, memory data is maintained in non-volatile random access memory (NVRAM) by a lifetime lithium energy supply that will maintain the memory content for at least 10 years. Unlike electrically erasable programmable read-only memory (EEPROM), the NVRAM iButton memory can be erased and rewritten as often as necessary without wearing out. It can also be erased or rewritten at the high speeds typical of complementary metal oxide semiconductor (CMOS) memory, without requiring the time-consuming programming of EEPROM.Since their introduction, iButton memory devices have been deployed in vast quantities as rugged portable data carriers, often in harsh environmental conditions. Among the large-scale uses are as transit fare carriers in Istanbul, Turkey; as maintenance record carriers on the sides of Ryder trucks; and as mailbox identifiers inside the mail compartments of the U.S. Postal Service's outdoor mailboxes. They are worn as earrings by cows in Canada to hold vaccination records, and they are used by agricultural workers in many areas as rugged substitutes for timecards.The iButton product line and its many applications are described at Dallas Semiconductor's iButton Web site, which is listed in the Resources section. Every iButton product is manufactured with a unique 8-byte serial number and carries a guarantee that no two parts will ever have the same number. Among the simplest iButtons are memory devices that can hold files and subdirectories and can be read and written like small floppy disks. In addition to these, there are iButtons with password-protected file areas for security applications, iButtons that count the number of times they have been rewritten for securing financial transactions, iButtons with temperature sensors, iButtons with continuously running date/time clocks, and even iButtons containing powerful microprocessors.Ⅲ.A WEA RABLE COMPUTERThe Java Ring is a tiny wearable computer with 6 kilobytes of RAM. Six K may not sound like much, but it is 20 percent more memory than the first computer I ever used (back in high school in 1973): an ancient (even at the time) Danish second-generation computer called Gier. The Gier took up an entire room and now I can carry more computer power on my finger.Even 6 K is enough to hold your secret codes, your credit cards numbers, your driver license, other wallet contents, and even some electronic cash. The ring can also store a few important URLs. Indeed, one of the current Java Ring demos is the ability for me to walk up to any computer in the world that has a Java Ring reader and have my home page loaded simply by touching the ring to the reader.(This is part of my introduction)The current JavaRing is admittedlymainly a demo, though it does perform usefultasks such as opening locked doors forauthorized personnel. In the future, it willobviously be possible to build rings withmuch more memory than 6 K, and manymore applications will be implemented.From a user interface perspective, onecan also hope that future rings will bedesigned by jewelry designers and look lessnerdy. Also, it would be possible to gain thesame functionality in a watch or a belt buckle.The key issue about a wearable computer isnot whether it is a ring or another form factor:the deciding point is that you will always2.A Wearable Compute rhave it with you. Many aspects of computingchange once there is no need to go to aspecial room to get at the computer.Ⅳ.KEEPING YOUR MONEY SAFEThe Crypto iButton hardware platform offers a unique set of special features expressly designed to prevent private keys and other confidential information from becoming available to hackers. Figure 1 shows a detail of the internal construction of the Crypto iButton. The silicon die containing the processor, ROM, and NVRAM memory is metallurgically bonded to the barrier substrate through which all electrical contacts are made. This barrier substrate and the triple-layer metal construction techniques employed in the silicon fabrication effectively deny access to the data stored in the NVRAM. If any attempt is made to penetrate these barriers, the NVRAM data is immediat ely erased. This construction technique and the use of NVRAM for the storage of private keys and otherconfidential data provides a much higher degree of data security than that afforded by EEPROM memory. The fact that the communication path between the Crypto iButton and the outside world is limited to a single data line provides additional security against hardware attacks by limiting the range of signals accessible to the hacker.In addition, the processor itself is driven by an unstabilized ring oscillator operating over a range of 10 to 20 megahertz, so that the clock frequency of the processor is not constant and cannot be determined by external means. This differs from the design of alternative devices in which the processor clock signal is injected by the reader and is therefore exactly determined by the host processor. External control of the clock provides a valuable tool to hackers, since they can repetitively cycle such a processor to the same point in its execution simply by applying the same nu mber of clock cycles. Control of the clock also affords a means to induce a calculation error and thereby obtain information that can ultimately reveal secret encryption keys. A 32-kilohertz crystal oscillator is used in the Java iButton to operate the time-of-day clock at a constant and well-controlled frequency that i s independent of the processor clock.Ⅴ.THE POSTAL SECURITY DEVICEFor over 10 years, Dallas Semiconductor also has been designing, making, and selling a line of highly secure microprocessors that are used in satellite TV descramblers, automatic teller machines, point-of-sale terminals, and other similar applications requiring cryptographic security and high resistance to attack by hackers. The U.S. Postal Service's (USPS) Information Based Indicia Program Postal Security Device Specification, intended to permit printing of valid U.S. postage on any PC, provided the first opportunity to combine two areas of expertise when a secure microprocessor was designed into an iButton.The resulting product, named the Crypto iButton, combines high processor performance, high-speed cryptographic primitives, and exceptional protection against physical and cryptographic attack. For example, the large integer modular exponentiation engine can perform 1024-bit modular exponentiations with a 1024-bit exponent in significantly less than a second. The ability to perform large integer modular exponentiations at high speed is central to RSA encryption, Diffie-Hellman key exchange, Digital Signature Standard (FIPS 186), and many other modern cryptographic operations.An agreement between Dallas Semiconductor and RSA Data Security Inc. provides a paid-up license for anyone using the Crypto iButton to perform RSA encryption and digital signatures so that no further licensing of the RSA encryption technology is required. High security is afforded by the ability to erase the contents of NVRAM extreme ly quickly. This feature, rapid zeroization, is a requirement for high security devices that may be subjected to attacks by hackers. As a result of its high security, the Crypto iButton is expected to win the FIPS 140-1 security certification by the National Institute of Standards and Technology (NIST).A special operating system was designed and stored in the ROM of the Crypto iButton to support cryptography and general-purpose financial transactions -- such as those required by the Postal Serviceprogram. While not a Java virtual machine, the E-Commerce firmware designed for this application had several points of similarity with Java, including an object-oriented design and a bytecode interpreter to interpret and execute Dallas Semiconductor's custom-designed E-Commerce Script Language. A compiler was also written to compile the high-level language representation of the Script Language to a bytecode form that could be interpreted by the E-Commerce VM. Although the E-Commerce firmware was intended primarily for the USPS application, the firmware supports a variety of general electronic commerce models that are suitable for many different applications. The E-Commerce firmware also supports cryptographic protocols for secure information exchange such as the Simple Key-Management for Internet Protocol (SKIP) developed by Sun Microsystems Inc. The E-Commerce iButton and the SDK for programming it are described in detail on the Crypto iButton home page.[1]Stephen C urry,the Javaworld website. [online].http://www.javaw /jw-04-1998/jw-04-javadev.html[2] Jakob Nielsen, [online]./papers/javaring.html[3] The SearchSOA website.[online]. /definition/Java-Ring。