applicationengine.java

采用tapestry的简单OA系统

package com.ejsun.entapps.presentation;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.engine.BaseEngine;
import org.apache.tapestry.request.RequestContext;
import org.apache.tapestry.request.ResponseOutputStream;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.ejsun.entapps.presentation.pages.ApplicationBasePage;
import com.ejsun.entapps.service.GenericServiceException;
import com.ejsun.entapps.service.InstallService;
import com.ejsun.entapps.service.impl.SpringServiceLocator;

/**
 * @author	Quake Wang (reference Tapestry Vlib example)
 * @since	2004-3-21
 * @version $Revision: 1.1 $
 * 
 **/

public class ApplicationEngine extends BaseEngine {
    private final static Log log = LogFactory.getLog(ApplicationEngine.class);

    private transient boolean killSession;

    protected void setupForRequest(RequestContext context) {
        super.setupForRequest(context);
        Global global = (Global) getGlobal();
        if (global.serviceLocator == null) {
			ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(context.getServlet().getServletContext());
			global.serviceLocator = new SpringServiceLocator(applicationContext);
			((InstallService) global.getService("installService")).install(); 
        }
    }

    protected void cleanupAfterRequest(IRequestCycle cycle) {
        super.cleanupAfterRequest(cycle);
        if (killSession) {
            try {
                HttpSession session = cycle.getRequestContext().getSession();

                if (session != null) {
                    session.invalidate();
                }
            } catch (IllegalStateException ex) {
                // Ignore.
            }
        }
    }

    public void logout() {
        Visit visit = (Visit) getVisit();

        if (visit != null) {
            visit.setUser(null);
            visit = null;
        }

        killSession = true;
    }

    protected void activateExceptionPage(IRequestCycle cycle, ResponseOutputStream output, Throwable cause)
        throws ServletException {
        if (cause.getCause() instanceof GenericServiceException && cycle.getPage() instanceof ApplicationBasePage) {
            ((ApplicationBasePage) cycle.getPage()).setErrorCode(cause.getCause().getMessage());
            try {
                super.renderResponse(cycle, output);
            } catch (IOException ioe) {
                log.error(ioe);
                throw new ServletException(ioe.getMessage(), ioe);
            }
        } else {
            super.activateExceptionPage(cycle, output, cause);
        }
    }
}