activator.java

使用OSGi框架开发的分布式电子辞典

/*
 * @(#)Activator.java
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
package cn.edu.ynu.sei.dict.web.service;

import cn.edu.ynu.sei.dict.core.service.IDictEditService;
import cn.edu.ynu.sei.dict.core.service.IDictQueryService;
import cn.edu.ynu.sei.dict.plugin.user.service.IUserManager;
import cn.edu.ynu.sei.dict.web.data.AddFriend;
import cn.edu.ynu.sei.dict.web.data.AddWord;
import cn.edu.ynu.sei.dict.web.data.CheckEditInfo;
import cn.edu.ynu.sei.dict.web.data.DeleteFriend;
import cn.edu.ynu.sei.dict.web.data.EditInfo;
import cn.edu.ynu.sei.dict.web.data.GetAttentionList;
import cn.edu.ynu.sei.dict.web.data.GetEditInfo;
import cn.edu.ynu.sei.dict.web.data.IsLogin;
import cn.edu.ynu.sei.dict.web.data.UserLogin;
import cn.edu.ynu.sei.dict.web.data.UserValidator;
import cn.edu.ynu.sei.dict.web.data.WordDetailReacher;
import cn.edu.ynu.sei.dict.web.data.WordQueryReacher;
import java.net.URL;
import java.util.Hashtable;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.knopflerfish.service.log.LogRef;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.ServiceEvent;
import org.osgi.framework.ServiceListener;
import org.osgi.framework.ServiceReference;
import org.osgi.service.http.HttpContext;
import org.osgi.service.http.HttpService;

/**
 * OSGi activator for StoneAge dictionary web application.
 * @author 88250
 * @author zy
 * @version 1.0.2.1, Mar 13, 2008
 */
public class Activator implements BundleActivator {

    private IDictQueryService wordReader;
    private IDictEditService  wordWriter;
    private IUserManager userManager;
    // This is my world
    static BundleContext bc;
    static LogRef log;
    static final String RES_ALIAS = "/";     // the http server root

    static final String RES_DIR = "/www";  // bundle resource directory 

    static final String SERVLET = "/servlet/";
    static final String USER_VALIDATOR_SERVLET_ALIAS = SERVLET + "uservalidator"; // a small servlet
    static final String USER_LOGIN_SERVLET_ALIAS = SERVLET + "userlogin";
    static final String WORD_DETAIL_REACHER_ALIAS = SERVLET + "worddetail";
    static final String WORD_QUERY_REACHER_ALIAS = SERVLET + "wordquery";
    static final String WORD_ADDWORD_ALIAS = SERVLET + "addword";
    static final String WORD_EDITWORD_ALIAS = SERVLET + "editword";
    static final String WORD_CHECKEDIT_ALIAS = SERVLET + "checkedit";
    static final String WORD_GETEDITINFO_ALIAS = SERVLET + "geteditinfo";
    static final String WORD_GETATTENLIST_ALIAS = SERVLET + "getattenlist";
    static final String USER_ADDFRIEND_ALIAS = SERVLET + "addfriend";
    static final String USER_DELETEFRIEND_ALIAS = SERVLET + "deletefriend";
    static final String USER_ISLOGIN_ALIAS = SERVLET + "islogin";
    Hashtable registrations = new Hashtable();

    public void start(BundleContext bundleContext) throws BundleException {
        ServiceReference sr = bundleContext.getServiceReference(IDictQueryService.class.getName());
        wordReader = (IDictQueryService) bundleContext.getService(sr);

        sr = bundleContext.getServiceReference(IDictEditService.class.getName());
        wordWriter = (IDictEditService) bundleContext.getService(sr);
        
        sr = bundleContext.getServiceReference(IUserManager.class.getName());
        userManager = (IUserManager) bundleContext.getService(sr);

        this.bc = bundleContext;
        this.log = new LogRef(bundleContext);

        ServiceListener listener = new ServiceListener() {

            public void serviceChanged(ServiceEvent ev) {
                ServiceReference sr = ev.getServiceReference();

                switch (ev.getType()) {
                    case ServiceEvent.REGISTERED:
                        setRoot(sr);
                        break;
                    case ServiceEvent.UNREGISTERING:
                        unsetRoot(sr);
                        break;
                }
            }
        };

        String filter = "(objectclass=" + HttpService.class.getName() + ")";

        try {
            bundleContext.addServiceListener(listener, filter);

            ServiceReference[] srl = bundleContext.getServiceReferences(null, filter);
            for (int i = 0; srl != null && i < srl.length; i++) {
                listener.serviceChanged(new ServiceEvent(ServiceEvent.REGISTERED,
                        srl[i]));
            }
        } catch (Exception e) {
            log.error("Failed to set up listener for http service", e);
        }
    }

    public void stop(BundleContext bc) throws BundleException {
    }

    void setRoot(ServiceReference sr) {

        if (registrations.containsKey(sr)) {
            return; // already done

        }

        log.info("set root for " + sr);

        HttpService http = (HttpService) bc.getService(sr);
        HttpContext context = new HttpContext() {

            public boolean handleSecurity(HttpServletRequest request,
                    HttpServletResponse response)
                    throws java.io.IOException {
                return true;
            }

            public URL getResource(String name) {
                // when registering the root, it seems
                // like we get no separator before the file.
                // Is that a bug?? Code below is a workaround      
                if (name.startsWith(RES_DIR) &&
                        name.length() > RES_DIR.length() &&
                        '/' != name.charAt(RES_DIR.length())) {
                    name = RES_DIR + "/" + name.substring(RES_DIR.length());
                }

                // default to index.html
                if (name.equals(RES_DIR)) {
                    name = "/www/index2.html"; // XXX default homepage

                }

                // and send the plain file
                URL url = getClass().getResource(name);
                return url;
            }

            public String getMimeType(String reqEntry) {
                return null; // server decides type

            }
        };

        try {

            http.registerResources(RES_ALIAS, RES_DIR, context);
            http.registerServlet(USER_VALIDATOR_SERVLET_ALIAS, new UserValidator(sr,userManager),
                    new Hashtable(), context);
            http.registerServlet(USER_LOGIN_SERVLET_ALIAS, new UserLogin(userManager), new Hashtable(), context);
            http.registerServlet(WORD_DETAIL_REACHER_ALIAS,
                    new WordDetailReacher(sr, wordReader), new Hashtable(), context);
              http.registerServlet(WORD_QUERY_REACHER_ALIAS, new WordQueryReacher(sr,wordReader),
                    new Hashtable(), context);
              http.registerServlet(WORD_ADDWORD_ALIAS, new AddWord(wordReader,wordWriter,userManager),
                    new Hashtable(), context);
              http.registerServlet(this.WORD_EDITWORD_ALIAS, new EditInfo(wordReader,wordWriter,userManager),
                    new Hashtable(), context);
              http.registerServlet(this.WORD_CHECKEDIT_ALIAS, new CheckEditInfo(),
                    new Hashtable(), context);
              http.registerServlet(this.WORD_GETEDITINFO_ALIAS, new GetEditInfo(),
                    new Hashtable(), context);
              http.registerServlet(this.WORD_GETATTENLIST_ALIAS, new GetAttentionList(userManager),
                    new Hashtable(), context);
              http.registerServlet(this.USER_ADDFRIEND_ALIAS, new AddFriend(userManager),
                    new Hashtable(), context);
              http.registerServlet(this.USER_DELETEFRIEND_ALIAS, new DeleteFriend(userManager),
                    new Hashtable(), context);
              http.registerServlet(this.USER_ISLOGIN_ALIAS, new IsLogin(),
                    new Hashtable(), context);

            registrations.put(sr, context);
        } catch (Exception e) {
            log.error("Failed to register resource", e);
        }
    }

    void unsetRoot(ServiceReference sr) {
        if (!registrations.containsKey(sr)) {
            return; // nothing to do

        }

        log.info("unset root for " + sr);

        HttpService http = (HttpService) bc.getService(sr);

        if (http != null) {
            http.unregister(RES_ALIAS);
            http.unregister(USER_VALIDATOR_SERVLET_ALIAS);
            bc.ungetService(sr);
        }
        registrations.remove(sr);
    }
}