controller.jsp

此程序都是企业级 的数据库开发程序 全面揭示了JAVA对数据库的操作

  <%@page import="java.util.*"%>
  <%@page import="java.io.*"%>
  <%@page import="org.w3c.dom.Document"%>
  <%@page import="mvc.*"%>

  <%

      /*
        The MVC framework shown for this chapter use the Xalan XSLT processor and Xerces XML parser.
        Xalan and Xerces are freely available from the http://xml.apache.org.  The MVC framework built
        in this chapter uses version 2.2D6 of the Xalan XSLT processor and version 1.3 of the Xerces
        XML parser.  In controller.jsp the org.w3c.dom.Document class comes from the Xerces jar file 
        (xerces.jar).
      */


      /*
         The controller JSP is the controller piece of the Model-View-Controller Framework.
         This piece will first try and retrieve the name of the XSL file the user wants to view.
         After the xslFileName is retrieved it will instantiate the Request handler.  The request
         handler will invoke the appropriate model. The model will return an XML document
         with all of the data to be presented to the end-user.  The controller.jsp will then
         the JspWriter out variable, the data returned from the RequestHandler, and the
         name of the XSL file that will be used to present the data.  The XSLTManager
         will carry out the merging of the XSL and XML document.
      */
      try{
        String requestValue = request.getParameter("Request");
        String actionValue  = request.getParameter("Action");

        /*Step 1 - Retrieve the name of the XSL file that is going to be used*/
        String  xslFileName = MVCHelper.getXSLFileName(requestValue,actionValue);

        if (xslFileName == null){
           throw new Exception("Unable to locate an XSL file that matches the request and action requested.  Request: "
                               + requestValue + " , Action: " + actionValue);
        }

        /*Step 2 - Instantiate the RequestHandler and process the user's request*/
        RequestHandler requestHandler = new RequestHandler();
        Document returnedData = requestHandler.process(request);

        /*Step 3 - Take the Document retrieved from the requesthandler and transform it to HTML*/
        XSLTManager xsltManager = new XSLTManager();
        xsltManager.transformOutput(out, returnedData, xslFileName);
      }
      catch(Exception e){
         MVCHelper.buildErrorPage(e, out);
      }
  %>