基于jsp在线音乐播放系统毕业设计外文文献及翻译

基于jsp在线音乐播放系统毕业设计外文文献及翻译内容摘要：

called. Then quickly Netscape LiveScript renamed JavaScript, Java developers with them from the same issued a statement. A statement Java and JavaScript will plement each other, but they are different, so the technology of the many dismissed the misunderstanding of the two technologies. JavaScript to create user interface control provides a scripting language. In fact, in the browser into the JavaScript code logic. It can support such effect: when the cursor on the Web page of a mobile user input validation or transform image. Microsoft also write out their JavaScript version and the JScript called. Microsoft and Netscape support JavaScript and JScript around a core characteristics and European Manufacturers by (ECMA) standards anization, the control standard of scripting language. ECMA its scripting language ECMAScript named. Servlets and JSPs often include fragments of information that are mon to an anization, such as logos, copyrights, trademarks, or navigation bars. The web application uses the include mechanisms to import the information wherever it is needed, since it is easier to change content in one place then to maintain it in every piece of code where it is used. Some of this information is static and either never or rarely changes, such as an anization39。 s logo. In other cases, the information is more dynamic and changes often and unpredictably, such as a textual greeting that must be localized for each user. In both cases, you want to ensure that the servlet or JSP can evolve independently of its included content, and that the implementation of the servlet or JSP properly updates its included content as necessary. You want to include a resource that does not change very much (such as a page fragment that represents a header or footer) in a JSP. Use the include directive in the including JSP page, and give the included JSP segment a .jspf extension. You want to include content in a JSP each time it receives a request, rather than when the JSP is converted to a servlet. Use the jsp:include standard action. You want to include a file dynamically in a JSP, based on a value derived from a configuration file. Use the jsp:include standard action. Provide the value in an external properties file or as a configuration parameter in the deployment descriptor. You want to include a fragment of an XML file inside of a JSP document, or include a JSP page in XML syntax. Use the jsp:include standard action for the includes that you want to occur with each request of the JSP. Use the jsp: element if the include action should occur during the translation phase. You want to include a JSP segment from outside the including file39。 s context. Use the c:import The operation principle and the advantages of JSP tags In this section of the operating principle of simple introduction JSP and strengths. For the first time in a JSP documents requested by the engine, JSP Servlet is transformed into a document JSP. This engine is itself a Servlet. The operating process of the JSP shown below: (1) the JSP engine put the JSP files converting a Java source files (Servlet), if you find the files have any grammar mistake JSP, conversion process will interrupt, and to the server and client output error messages. (2) if converted, with the engine JSP javac Java source file piler into a corresponding scaleup files. (3) to create a the Servlet (JSP page), the transformation of the Servlet jspInit () method was executed, jspInit () method in the life cycle of Servlet executed only once. (4) jspService () method invocation to the client requests. For each request, JSP engine to create a new thread for processing the request. If you have multiple clients and request the JSP files, JSP engine will create multiple threads. Each client requests a thread. To execute multithread can greatly reduce the requirement of system resources, improving the concurrency value and response time. But also should notice the multithread programming, due to the limited Servlet always in response to memory, so is very fast. (5) if the file has been modified. The。