Java
Java (TM) is developed by the US Shengyang Computer Company (Sun Microsystems, Inc.)
The first kind of "hardware / software neutral" interaction can be used in the International Internet (Internet)
Ability of programming language. Java has launched the attention and enthusiastic participation discussion of various media in the world.
Such as Time, Business Weekly, CNN, etc., it can be seen, in fact, in fact,
With Java's function, it is bound to set off another climax in the information industry, and for the development of the network,
It will enter another new era.
Foreword
"Java" starts from the 1995 summer holiday, which is highly paid by the computer industry, especially in Internet and multimedia-related products. Why is Java so big? Some people do such a metaphor: Java's relationship between the World Wide Web (WWW) is like the Spreadsheet and PC (PC). What is the feature of java? Mac O / S, Windows, or NT, etc .; KestenBaum, 1995). Hereinafter, Java will be described in order, first of all, Java's development history is introduced in Java language, and the second is a brief introduction to Java Applet and HotJava.
Bamboo
Java introduction
Firstly, in the way, Java's development history and its background (the following content is organized from Java FAQ List and Tutorial and the Java Language: a White Paper, if you want to know in depth, please refer to the original text): Please refer to the original text): ※ Java starts to develop ? (WHEN) The earliest detrocessestable in April 1991, the Sun Project started to develop consumer electronics, the languages used are C, C , and Oak (for Java language) Formerly), after the language itself and the market, the development of consumer electronics cannot achieve the current expected goal, plus the rise of the network, and the green plan has changed the direction of development, this is 1994. ※ Why is it called Java? (Why) "Java" is a fierce discussion of the Java Development Team of Shengyang Computer, who has been in many times, has been selected after numerous discussions. Livaces, Animation, Speed, Interactivity features the features you want to express when you choose the name. "Java" is standing out in countless suggestions, and "Java" is not composed of several single words, but from many programming men love the hot, insecured coffee. ※ Who has developed Java? (WHO) Answer is the Java Development Group of Shengyang Computer, USA, early member (green project) is Patrick Naughton, James Gosling, & Mike Sheridan, and now everyone is a more familiar member is James Gosling, and now Java Development Panel member is also Increased a lot, of course, you also have the opportunity to become a member of the group, the chance is always greater than zero. ※ There have been Java there? (Where) is also to ask Java's birthplace? The answer is the United States. ※ What special or characteristics is Java? (WHAT) See the beginning and next paragraph of this unit. ※ How can I find the Java information I need? (How to) On the Internet, you can connect to Sun's Java WWW website, the site node address is http://java.sun.com/, or http://www.javasoft.com/. It can almost you can find the Java information you need, but the language is an obstacle, at least for some people; it doesn't matter, there are many websites that have many websites in China provide Chinese Java information. There will be more websites in the future. Related Information. ※ How can I see Java's effect? (How do i) First you need to have a browser with Java, such as Netscape Navigator 2.0 or more, Netscape Navigator, or Sun Company's Hotjava browser, for personal computer users, job system It is Windows 95 or Windows NT. From the "Java Small History" from the previous section, we know that Java's development history is now introducing Java language. Java is developed in response to the difficulties of writing C language programs, first, just a part of a consumer electronic product planner, C language is used, but from the beginning of the compilation problem until The final series of problems have caused discarding C language while having the production of Java languages.
Sun is to be a simple (Object Oriented), interpreted, a robust, secure, structural neutrality (Architecture Neutral) ), Portable, high performance, dynamic programming (Dynamic) programming (in the Java Language: A White Paper, 1995). The Characteristics of the above Java language will be clearly described in Sun's Java Language White Paper. 1. Simple: It is easy to write programs that don't need long training, and can meet modern needs. The program is also a simple feature such that the software can be performed on a small machine, and the basic interpreter is approximately 40K, and the basic library is added, about 215K. 2. Object-oriented: Object-oriented design is a focus on data and interface skills. If a woodwork is a metaphor, an object-oriented woodworking, his (her) the most important focus is the mood chair to be done, and the second is the tool you need; the reaction; a woodman with non-faced objects, he (she) It is only a tool. The nearest plug is also the focus of object-oriented design. 3. Distributed: Java has a very comprehensive library and is easy to cooperate with TCP / IP communication agreements such as HTTP and FTP. The Java Application (Applications) can use the item on the Internet, just use a local file system (Local File System) as through the URLS connection. 4. Robust: The program written by Java can be performed in a variety of situations and has its stability. The maximum difference between Java and C / C is that Java has a pointer model to exclude the possibility of overwriting memory and corrupting data. 5. Secure: Java is designed for network and distributed environments, security must be a very important consideration. Java has several interlocks of interlocks, which can effectively prevent the occurrence of viruses from incurring and destructive behavior. 6. Architecture neutral: In general, the network is made by many of many different models, and the CPU and job system architecture are different; therefore, how to make an application can be in each A machine is executed, it is a problem. Fortunately, Java's compiler produces a structural file format (Object File Format); this makes the compiled code to be executed in many processors. 7. Portable: The size of the original data is specified, such as "float", has always indicated a 32-bit IEEE 754 floating point calculation number, which has this common feature because most of the CPUs have this common feature. The library belongs to a part of the system, which defines some portable program interfaces, and Java itself has good portability. 8. Interpretated: Java interpreter can perform Java bitmines directly on any machine, so time saving, time saving, this is great for shortening the development process of the program help. 9. High Performance: The Java bit element can be converted into machine code, and the effect of converting the slave border to the machine code is almost not separate from C and C .
10. Multi Threaded: Java language has multi-threaded features, which is helpful for interactive response capabilities and instant execution behaviors. 11. Dynamic: Java is more dynamic in Java than C or C , which can adapt to the time changing environment, Java does not recompile the program due to the update of the library. For details on the Java Chinese White Paper, please refer to the "San Moon" issued by the Merchants Shengyang Computer Taiwan Branch, "Java Language White Paper" in February 1996. In addition, Hankings Sense of Java also proposes his description of Java's wrong ideas and ideas. It is hereby extracted: 1. "Java is a language written in Web Pages, just like HTML As VRML "In fact, Java is not like the description language of HTML (Description Language), but a programming language (Programming Language). Description Language indicates content and location, and the programming language describes a process of generating results. 2. "Java language is easy to learn and use, unlike C, C and other programming languages" Java is a programming language. Is Java easy to learn? Java may be easier than C or C , but still a programming language, not a description language. 3. "Java code is portable, but C and C are not" Source Code) is a bit of portability than C language, and the difference is the Tag code of Java. The Java code is compiled on a machine, and can perform on all machines as long as there is a Java interpreter on that machine. 4. "Java can expand and perform anything on the machine" theoretically, Java Applet (Java applet) can do anything, such as analog 3D VRML model, play movies, generating sound .... But in fact, a small application (Applet) can only be executed on that page without executing on that page. At the same time, Java is also limited by the functionality of the library. 5. "Java is suitable for building large applications" If Java is suitable for large programs, Java is not suitable for web browsers. The first commercial Java Applets (Applix's Java-based Spreadsheet is not fully use Java, which only uses Java as a user interface, and all processing work is using the CGI code. 6. "Java is interpreted, Basic is explained, so java = Basic" Although Java is indeed using an interpreter, but in fact, Java is relatively similar to C or C , but with Basic or APL The complete interpretation language is relatively similar. It is relatively similar, but it is relatively similar to the fully interpreted language such as Basic or APL. 7. "Java Remove the CGI Command Manuscript (Scripts) and Programs" Java Applets will replace part of CGI. In some cases, Java Applets can replace some server-side code, but most cases, Java is still unable to replace CGI Scripts based on security reasons or considerations. 8. "Netscape's JavaScript is related to Java" more similar, but completely interpreted with Basic or APLs. It is relatively similar, but it is relatively similar to the fully interpreted language such as Basic or APL.
