1、48 附录 1 JSP Profile JSP (JavaServer Pages) is initiated by Sun Microsystems, Inc., with many companies to participate in the establishment of a dynamic web page technical standards. JSP technology somewhat similar to ASP technology, it is in the traditional HTML web page document (*. htm, *. html) t
2、o insert the Java programming paragraph (Scriptlet) and JSP tag (tag), thus JSP documents (*. jsp). Using JSP development of the Web application is cross-platform that can run on Linux, is also available for other operating systems. JSP technology to use the Java programming language prepared by the
3、 category of XML tags and scriptlets, to produce dynamic pages package processing logic. Page also visit by tags and scriptlets exist in the services side of the resources of logic. JSP page logic and web page design and display separation, support reusable component-based design, Web-based applicat
4、ion development is rapid and easy. Web server in the face of visits JSP page request, the first implementation of the procedures of, and then together with the results of the implementation of JSP documents in HTML code with the return to the customer. Insert the Java programming operation of the da
5、tabase can be re-oriented websites, in order to achieve the establishment of dynamic pages needed to function. JSP and Java Servlet, is in the implementation of the server, usually returned to the client is an HTML text, as long as the client browser will be able to visit. JSP 1.0 specification of t
6、he final version is launched in September 1999, December has introduced 1.1 specifications. At present relatively new is JSP1.2 norms, JSP2.0 norms of the draft has also been introduced. JSP pages from HTML code and Java code embedded in one of the components. The server was in the pages of client r
7、equests after the Java code and then will generate the HTML pages to return to the client browser. Java Servlet JSP is the technical foundation and large-scale Web application development needs of Java Servlet and JSP support to complete. JSP with the Java technology easy to use, fully object-orient
8、ed, and a platform-independent and secure, mainly for all the characteristics of the Internet. JSP technology strength (1) time to prepare, run everywhere. At this point Java better than PHP, in addition to systems, the code not to make any changes. (2) the multi-platform support. Basically on all p
9、latforms of any development environment, in any environment for deployment in any environment in the expansion. Compared ASP / PHP limitations are obvious. (3) a strong scalability. From only a small Jar documents can run Servlet / JSP, to the multiple servers clustering and load balancing, to multi
10、ple Application for transaction processing, information processing, a server to numerous servers, Java shows a tremendous Vitality. (4) diversification and powerful development tools support. This is similar to 49 the ASP, Java already have many very good development tools, and many can be free, and
11、 many of them have been able to run on a variety of platforms under. JSP technology vulnerable (1) and the same ASP, Java is the advantage of some of its fatal problem. It is precisely because in order to cross-platform functionality, in order to extreme stretching capacity, greatly increasing the c
12、omplexity of the product. (2) Javas speed is class to complete the permanent memory, so in some cases by the use of memory compared to the number of users is indeed a minimum cost performance. On the other hand, it also needs disk space to store a series of. Java documents and. Class, as well as the
13、 corresponding versions of documents. JSP six built-in objects: request, response, out, session, application, config, pagecontext, page, exception. 1. Request for: The object of the package of information submitted by users, by calling the object corresponding way to access the information package,
14、namely the use of the target users can access the information. 2. Response object: The customers request dynamic response to the client sent the data. 3. session object 1. What is the session: session object is a built-in objects JSP, it in the first JSP pages loaded automatically create, complete t
15、he conversation of management. From a customer to open a browser and connect to the server, to close the browser, leaving the end of this server, known as a conversation. When a customer visits a server, the server may be a few pages link between repeatedly, repeatedly refresh a page, the server sho
16、uld be through some kind of way to know this is the same client, which requires session object. 2. session object ID: When a customers first visit to a server on the JSP pages, JSP engines produce a session object, and assigned a String type of ID number, JSP engine at the same time, the ID number s
17、ent to the client, stored in Cookie, this session objects, and customers on the establishment of a one-to-one relationship. When a customer to connect to the server of the other pages, customers no longer allocated to the new session object, until, close your browser, the client-server object to can
18、cel the session, and the conversation, and customer relationship disappeared. When a customer re-open the browser to connect to the server, the server for the customer to create a new session object. 4. aplication target 1. What is the application: Servers have launched after the application object,
19、 when a customer to visit the site between the various pages here, this application objects are the same, until the server is down. But with the session difference is that all customers of the application objects are the same, that is, all customers share this built-in application objects. 2. application objects commonly used methods:
