selectdivisionaction.java

使用Servlet和JSP进行Web组件开发

package sl314.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
// Struts classes
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;
// Model classes
import sl314.model.RegisterService;
import sl314.model.League;
import sl314.model.Player;
import java.util.List;
import java.util.LinkedList;
import javax.servlet.ServletContext;


public class SelectDivisionAction extends Action {
    
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request,
            HttpServletResponse response) {
        
        // Keep a set of strings to record form processing errors.
        List errorMsgs = new LinkedList();
        // Store this set in the request scope, in case we need to
        // send the ErrorPage view.
        request.setAttribute("errorMsgs", errorMsgs);
        
        try {
            
            // Retrieve form parameters.
            String division = request.getParameter("division").trim();
            
            // Verify 'Select Division' form fields
            if ( division.equals("UNKNOWN") ) {
                errorMsgs.add("You must select a division.");
            }
            
            // Send the ErrorPage view if there were errors
            if ( ! errorMsgs.isEmpty() ) {
                return mapping.findForward("error");
            }
            
            // Retrieve the league and player objects from the session-scope
            HttpSession session = request.getSession();
            League league = (League) session.getAttribute("league");
            Player player = (Player) session.getAttribute("player");
            
            ServletContext context = getServlet().getServletContext();
            String dataDirectory = (String)context.getAttribute("sl314.model.dataDirectory");
            RegisterService registerSvc = new RegisterService(dataDirectory);
            // Perform the registration
            registerSvc.register(league, player, division);
            
            // Send the Success view
            return mapping.findForward("success");
            
            // Handle any unusual exceptions
        } catch (RuntimeException e) {
            // Log stack trace
            e.printStackTrace(System.err);
            
            // Send the Error view if there were errors
            errorMsgs.add(e.getMessage());
            return mapping.findForward("error");
            
        } // END of try-catch block
        
    } // END of execute method
    
} // END of SelectDivisionAction class