4.1.4 Configuring JSP in web

4.1.4 Configuring JSP in web

1. An app can use JavaServer Pages (JSPs) to implement web pages. JSPs are servlets defined using static content (such as HTML) mixed with Java code.

2. App Engine supports automatic compilation and URL mapping for JSPs. A JSP file in the application's WAR (outside of WEB-INF/)

3. Configuring JSP Tag Libraries

   • 1) Weblogic Server, in accordance with the Servlet 2.2 specification provides the ability to create and use custom JSP tags.
   • 2) Custom JSP tags are Java classes that can be called from within a JSP page.
   • 3) To create custom JSP tags, you place them in a tag library and define their behavior in a tag library descriptor (TLD) file.
   • 4) You can install JSP tag libraries with the <taglib> element.
   • 5) Note that App Engine provides the JavaServer Pages Standard Tag Library(JSTL), and you do not need to install it.
   • 6) A tag library has a path to the JSP Tag Library Descriptor (TLD) file (<taglib-location>) and a URI that JSPs use to select the library for loading (<taglib-uri>). This URI pattern must match the value in the taglib directive in your JSP pages.
   • 7) This TLD must be made available to the Web Application containing the JSP by defining it in the Web Application deployment descriptor.
   • 8) It is a good idea to place the TLD file in the WEB-INF directory of your Web Application, because that directory is never available publicly.
   • For example, if the taglib directive in the JSP page is: <%@ taglib uri="myTaglib" prefix="taglib" %>
   • and the TLD is located in the WEB-INF directory of your Web Application, you would create the following entry in the Web Application deployment descriptor: <taglib>     <taglib-uri>myTaglib</taglib-uri>    <taglib-location>WEB-INF/myTLD.tld</taglib-location> </taglib>