fullscreendispatcherengine.java

java 写的一个新闻发布系统

//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//


package org.jahia.engines.applications;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Properties;
import java.util.StringTokenizer;

import org.jahia.data.JahiaData;
import org.jahia.engines.JahiaEngine;
import org.jahia.exceptions.JahiaException;
import org.jahia.params.ParamBean;
import org.jahia.registries.ServicesRegistry;

/**
 * <p>Title: Full screen application dispatcher engine</p>
 * <p>Description: The goal of this engine is to allow applications to "take"
 * over the HTML screen, without Jahia giving up it's hand. This can be useful
 * for all types of applications.</p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: Jahia Ltd</p>
 * @author Serge Huber
 * @version 1.0
 */

public class FullScreenDispatcherEngine implements JahiaEngine {

    public static final String ENGINE_NAME = "appdispatcher";

    public FullScreenDispatcherEngine () {
    }

    public boolean authoriseRender (ParamBean jParams) {
        // render is always authorized as even guest users might need this.
        // Actually the rendering is controlled more by the application than
        // by the user.
        return true;
    }

    public String renderLink (ParamBean jParams, Object theObj) throws JahiaException {
        String resultURL;

        Properties paramPairs = new Properties ();
        // paramPairs.setProperty("fieldid", )
        paramPairs.setProperty (ParamBean.PAGE_ID_PARAMETER,
                Integer.toString (jParams.getPageID ()));

        resultURL = jParams.composeEngineUrl (ENGINE_NAME, paramPairs, "");
        return resultURL;
    }

    public boolean needsJahiaData (ParamBean jParams) {
        return false;
    }

    public void handleActions (ParamBean jParams, JahiaData jData)
            throws JahiaException {
        String appUniqueIDStr = jParams.getParameter ("appid");
        if (appUniqueIDStr == null) {
            throw new JahiaException (
                    "Error while displaying application",
                    "Missing appID parameter for engine " + FullScreenDispatcherEngine.ENGINE_NAME,
                    JahiaException.APPLICATION_ERROR,
                    JahiaException.ERROR);
        }
        StringTokenizer strToken = new StringTokenizer (appUniqueIDStr, "_");
        String fieldIDStr = strToken.nextToken ();
        String appIDStr = strToken.nextToken ();
        int fieldID = Integer.parseInt (fieldIDStr);
        String appOutput =
                ServicesRegistry.getInstance ().getJahiaApplicationsDispatchingService ().getAppOutput (fieldID, appIDStr, jParams);
        try {
            PrintWriter out = jParams.getResponse ().getWriter ();
            out.print (appOutput);
            out.flush ();
        } catch (IOException ioe) {
            throw new JahiaException (
                    "Error while displaying application output",
                    "Couldn't get HttpResponse PrintWriter instance",
                    JahiaException.APPLICATION_ERROR,
                    JahiaException.ERROR, ioe);
        }
    }
}