JAVA If 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 language built 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。76926

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, 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’ve 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 you’ll be more productive sooner。

B。原文的翻译

JAVA 如果说一种脚本编制语言能够帮助解决百分之八十的客户端程序设计的问题，那么剩下的百分之二十又该怎么办呢？难道他们真的是一些高难度的问题吗？ 使用JAVA对于解决这种问题是非常流行的。JAVA是一个功能强大，安全性高，可以跨国际通用的编程语言平台使用，同时它是一种具有强大生命力的语言。对JAVA语言的扩展是不断进行的，JAVA提供的语言特性和库，能够很好地解决传统语言不能解决的问题，比如多线程操作、数据库访问、网络程序设计以及分布式计算等等。JAVA通过小应用程序巧妙地解决了客户端编程的问题。论文网