JSP coding Specification

. The presentation layer of JSP/jsp bean should be as thin and simplified as possible.

. Remember that most JSP pages should be read-only views, and the page bean provides the model.

. JSP and JSP bean should be designed together

. Remove the business logic from the JSP as reasonably as possible. The specific HTTP logic (such as Cookie processing) belongs to the bean or support class, rather than in JSP.

. Try to put the condition logic in the controller rather than in the view.

. Follow standard naming conventions for JSP, included files, JSP beans, and classes that implement extension tags. For example:
JSP controller xxxxcontroller. jsp
Included: JSP _ descriptivenameoffragment. jsp
JSP page model Bean: <pagename> bean, such as loginbena. Java
JSP session Bena: xxxxsessionbean
Tag class: xxxxtag, xxxxtagextrainfo

. You should avoid using the page introduction command in JSP. The import command will promote the real-name listing of classes rather than the instantiation of JSP beans:
No: <% @ page import = "com. java. util. *" %>
Usage: <% java. util. List L = new java. util. Using list (); %>

. JSP should not directly access request parameters. Bean should execute such a process and output the processed model data.

. JSP should not access the property file or use JNDI. Bean can access attributes.

. If all attributes of the JSP bean cannot be mapped from the page request, you should try to set the attributes in the <JSP: usebean> tag.

. Avoid designing pages that display both forms and processing results.

. Avoid code duplication in JSP. Put the function to be repeated in an included JSP, Bean, or tag extension so that it can be reused.

. JSP beans should never generate html

. In JSP, you should avoid using out. println () to generate page content.

. The JSP layer should not directly access data, including JDBC database access and EJB access.

. In terms of length, the scriptlests code should not exceed 5 lines.

. In addition to JSP beans, JSP should not instantiate complex readable and writable objects. In this case, it is possible to execute inappropriate business logic in JSP.

. JSP beans should not contain a large amount of data.

. If <JSP: Forward> and <JSP: Include mark> are used, and simple type values must be used to communicate with external pages, one or more <JSP: param> elements should be used.

. Custom tags should be used where appropriate logic is removed from JSP.

. Use the <JSP: Forward> tag with caution. In JSP, it is an equivalent Goto.

. Hidden comments should be used to prevent HTML output from being too large.

. Avoid Exception Handling in JSP

. Each JSP file should use an error page to handle exceptions that cannot be recovered from it.

. On the JSP error page, use HTML annotations to display the exception tracking information that is passed to the page.

. The jspinin () method and jspdestroy () method are used only to obtain performance benefits. Obtaining and discarding resources is a task of JSP beans and marking the processor, rather than being handled by JSP.

. If there is no good reason, do not define methods and internal content in JSP.