【文章內(nèi)容簡介】 ther foot Java munity did not invent the idea of designing pages as a mixture of static HTML and dynamic code marked with special example, ColdFusion did it years ASp(a product from the very software pany of the aforementioned manager)popularized this approach before JSp came along and decided to jump on the fact, JSp not only adopted the general idea, it even used many of the same special tags as ASp , the question bees: why use JSp instead of one of these other technologies? Our first response is that we are not arguing that everyone of those other technologies are quite good and are reasonable options in some other situations, however, JSp is clearly are a few of the and Active Server pages(ASp).NET is welldesigned technology from is the part that directly petes with servlets and advantages of JSp are , JSp is portable to multiple operating systems and Web servers。you aren39。t locked into deploying on Windows and the platform runs on a few nonWindows platforms, the ASp part does cannot expect to deploy serious applications on multiple servers and operating some applications, this difference does not others, it matters , for some applications the choice of the underlying language matters example, 39。s C language is very well designed and is similar to Java, fewer programmers are familiar with either the core C syntax or the many auxiliary addition, many developers still use the original version of this version, JSp has a clear advantage for the dynamic JSp, the dynamic part is written in Java, not VBScript or another ASpspecific language, so JSp is more powerful and better suited to plex applications that require reusable could make the same argument when paring JSp to the previous version of ColdFusion。with JSp you can use Java for the “real code” and are not tied to a particular server , the current release of ColdFusion is within the context of a J2EE server, allowing developers to easily mix ColdFusion and servlet/JSp pHppHp(a recursive acronym for “pHp: Hypertext preprocessor”)is a free, opensource, HTMLembedded scripting language that is somewhat similar to both ASp and advantage of JSp is that the dynamic part is written in Java, which already has an extensive ApI for networking, database access, distributed objects, and the like, whereas pHp requires learning an entirely new, less widely used second advantage is that JSp is much more widely supported by tool and server vendors than is pure ServletsJSp doesn39。t provide any capabilities that couldn39。t, in principle, be acplished with fact, JSp documents are automatically translated into servlets behind the it is more convenient to write(and to modify!)regular HTML than to use a zillion println statements to generate the , by separating the presentation from the content, you can put different people on different tasks: your Web page design experts can build the HTML by using familiar tools and either leave places for your servlet programmers to insert the dynamic content or invoke the dynamic content indirectly by means of XML this mean that you can just learn JSp and forget about servlets? Absolutely not!JSp developers need to know servlets for four reasons: pages get translated into can39。t understand how JSp works without understanding consists of static HTML, specialpurpose JSp tags, and Java kind of Java code? Servlet code!You can39。t write that code if you don39。t understand servlet tasks are better acplished by servlets than by is good at generating pages that consist of large sections of fairly well structured HTML or other character are better for generating binary data, building pages with highly variable structure, and performing tasks(such as redirection)that involve little or no tasks are better acplished by a bination of servlets and JSp than by either servlets or JSp JavaScriptJavaScript, which is pletely distinct from the Java programming language, is normally used to dynamically generate HTML on the client, building parts of the Web page as the browser loads the is a useful capability and does not normally overlap with the capabilities of JSp(which runs only on the server).JSp pages still include SCRIpT tags for JavaScript, just as normal HTML pages fact, JSp can even be used to dynamically generate the JavaScript that will be sent to the , JavaScript is not a peting technology。it is a plementary is also possible to use JavaScript on the server, most notably on Sun ONE(formerly iplanet), IIS, and BroadVision , Java is more powerful, flexible, reliable, and WebMacro or VelocityJSp is by no means people have pointed out features that could be is a good thing, and one of the advantages of JSp is that the specification is controlled by a munity that draws from many different , the technology can incorporate improvements in successive , some groups have developed alternative Javabased technologies to try to address these , in our judgment, is a a thirdparty tool like Apache Struts that augments JSp and servlet technology is a good idea when that tool adds sufficient benefit to pensate for the additional using a nonstandard tool that tries to replace JSp is a bad choosing a technology, you need to weigh many factors: standardization, portability, integration, industry support, and technical arguments for JSp alternatives have focused almost exclusively on the technical features portability, standardization, and integration are also very example, the servlet and JSp specifications define a standard directory structure for Web applications and provide standard files(.war files)for deploying Web JSppatible servers must support these can be set up to apply to any number of servlets or JSp pages, but not to nonstandard same goes for Web application security , the tremendous industry support for JSp and servlet technology results in improvements that mitigate many of the criticisms of example, the JSp Standard Tag Library and the JSp expression language a