desktopimpl.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* DesktopImpl.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Wed Jun 22 09:50:57     2005, Created by tomyeh
}}IS_NOTE

Copyright (C) 2005 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui.impl;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;
import java.util.LinkedHashMap;

import org.zkoss.lang.D;
import org.zkoss.lang.Strings;
import org.zkoss.util.CacheMap;
import org.zkoss.util.Cache;
import org.zkoss.util.logging.Log;
import org.zkoss.util.media.Media;
import org.zkoss.io.Serializables;

import org.zkoss.zk.mesg.MZk;
import org.zkoss.zk.ui.WebApp;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.Session;
import org.zkoss.zk.ui.Sessions;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Executions;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.ComponentNotFoundException;
import org.zkoss.zk.ui.metainfo.LanguageDefinition;
import org.zkoss.zk.ui.util.Configuration;
import org.zkoss.zk.ui.util.Monitor;
import org.zkoss.zk.ui.util.DesktopSerializationListener;
import org.zkoss.zk.ui.util.EventInterceptor;
import org.zkoss.zk.ui.event.Event;
import org.zkoss.zk.ui.event.Events;
import org.zkoss.zk.ui.ext.render.DynamicMedia;
import org.zkoss.zk.ui.sys.PageCtrl;
import org.zkoss.zk.ui.sys.SessionCtrl;
import org.zkoss.zk.ui.sys.ExecutionCtrl;
import org.zkoss.zk.ui.sys.ComponentCtrl;
import org.zkoss.zk.ui.sys.ComponentsCtrl;
import org.zkoss.zk.ui.sys.RequestQueue;
import org.zkoss.zk.ui.sys.DesktopCache;
import org.zkoss.zk.ui.sys.WebAppCtrl;
import org.zkoss.zk.ui.sys.DesktopCtrl;
import org.zkoss.zk.ui.sys.EventProcessingThread;
import org.zkoss.zk.ui.sys.IdGenerator;
import org.zkoss.zk.ui.sys.ServerPush;
import org.zkoss.zk.ui.impl.EventInterceptors;
import org.zkoss.zk.au.out.AuBookmark;
import org.zkoss.zk.device.Device;
import org.zkoss.zk.device.Devices;
import org.zkoss.zk.device.DeviceNotFoundException;

/**
 * The implementation of {@link Desktop}.
 *
 * <p>Note: though {@link DesktopImpl} is serializable, it is designed
 * to work with Web container to enable the serialization of sessions.
 * It is not suggested to serialize and desrialize it directly since
 * many fields might be lost.
 *
 * <p>On the other hand, it is OK to serialize and deserialize
 * {@link Component}.
 *
 * @author tomyeh
 */
public class DesktopImpl implements Desktop, DesktopCtrl, java.io.Serializable {
	private static final Log log = Log.lookup(DesktopImpl.class);
    private static final long serialVersionUID = 20070416L;

	/** Represents media. It must be distinguishable from component's ID. */
	private static final String MEDIA_PREFIX = "med";

	private transient WebApp _wapp;
	private transient Session _sess;
	private String _id;
	/** The current directory of this desktop. */
	private String _dir;
	/** The path of the request that causes this desktop to be created. */
	private final String _path;
	/** The URI to access the update engine. */
	private final String _updateURI;
	/** Map(String id, Page page). */
	private final Map _pages = new LinkedHashMap(3);
	/** Map (String uuid, Component comp). */
	private transient Map _comps;
	/** A map of attributes. */
	private transient Map _attrs;
		//don't create it dynamically because PageImp._ip bind it at constructor
	private transient Execution _exec;
	/** Next available key. */
	private int _nextKey;
	/** Next available UUID. */
	private transient int _nextUuid;
	/** A special prefix to UUID generated by this desktop.
	 * It is used to avoid ID conflicts with other desktops in the same
	 * session.
	 * Since UUID is long enough plus this prefix, the chance to conlict
	 * is almost impossible.
	 */
	private String _uuidPrefix;
	/** The request queue. */
	private transient RequestQueue _rque;
	private String _bookmark = "";
	/** The device type. */
	private String _devType = "ajax";
	/** The device. */
	private transient Device _dev; //it will re-init each time getDevice called
	/** A map of media (String key, Media content). */
	private Cache _meds;
	/** ID used to identify what is stored in _meds. */
	private int _medId;
	/** The server push controller, or null if not enabled. */
	private ServerPush _spush;
	/** The event interceptors. */
	private final EventInterceptors _eis = new EventInterceptors();

	private static final int MAX_RESPONSE_SEQUENCE = 1024;
	/** The response sequence ID. */
	private int _respSeqId = MAX_RESPONSE_SEQUENCE - 1;
		//so the next value will be 0

	/** Whether any onPiggyback listener is registered. */
	private boolean _piggybackListened;
	/**
	 * @param updateURI the URI to access the update engine (no expression allowed).
	 * Note: it is NOT encoded yet.
	 * @param path the path that causes this desktop to create.
	 * If null or empty is specified, it means not available.
	 * @param deviceType the device type.
	 * If null or empty is specified, "ajax" is assumed.
	 */
	public DesktopImpl(WebApp wapp, String updateURI, String path, String deviceType) {
		if (updateURI == null || wapp == null)
			throw new IllegalArgumentException("null");

		//Feature 1811241: we create a temporary exec (in WebManager.newDesktop),
		//so DesktopInit can access Executions.getCurrent
		final Execution exec = Executions.getCurrent();
		if (exec != null)
			((ExecutionCtrl)exec).setDesktop(this);

		_wapp = wapp;
		_updateURI = updateURI;
		init();
		_sess = Sessions.getCurrent(); //must be the current session

		String dir = null;
		if (path != null) {
			_path = path;
			final int j = path.lastIndexOf('/');
			if (j >= 0) dir = path.substring(0, j + 1);
		} else {
			_path = "";
		}
		setCurrentDirectory(dir);
		if (deviceType != null && deviceType.length() != 0)
			setDeviceType(deviceType);

		final Configuration config = _wapp.getConfiguration();
		_exec = exec; //fake
		try {
			final WebAppCtrl wappc = (WebAppCtrl)_wapp;
			final DesktopCache dc = wappc.getDesktopCache(_sess);
			final IdGenerator idgen = wappc.getIdGenerator();
			if (idgen != null)
				_id = idgen.nextDesktopId(this);
			if (_id == null)
				_id = Strings.encode(
					new StringBuffer(12).append("g"), dc.getNextKey()).toString();
			updateUuidPrefix();

			config.invokeDesktopInits(this); //it might throw exception

			dc.addDesktop(this); //add to cache after invokeDesktopInits

			final Monitor monitor = config.getMonitor();
			if (monitor != null) {
				try {
					monitor.desktopCreated(this);
				} catch (Throwable ex) {
					log.error(ex);
				}
			}
		} finally {
			_exec = null;
		}
	}
	/** Initialization for contructor and de-serialized. */
	private void init() {
		_rque = newRequestQueue();
		_comps = new HashMap(41);
		_attrs = new HashMap();
	}
	/** Updates _uuidPrefix based on _id. */
	private void updateUuidPrefix() {
		_uuidPrefix = _id.substring(1, _id.length() <= 2 ? 2: 3);
			//the first few chars because of the encode's algorithm
	}

	public String getId() {
		return _id;
	}

	/** Creates the request queue.
	 * It is called when the desktop is initialized.
	 *
	 * <p>You may override it to provide your implementation of
	 * {@link RequestQueue} to control how to optimize the AU requests.
	 *
	 * <p>Default: creates an instance from {@link RequestQueueImpl};
	 *
	 * @since 2.4.0
	 */
	protected RequestQueue newRequestQueue() {
		return new RequestQueueImpl();
	}

	//-- Desktop --//
	public String getDeviceType() {
		return _devType;
	}
	public Device getDevice() {
		if (_dev == null)
			_dev = Devices.getDevice(_devType);
		return _dev;
	}
	public void setDeviceType(String deviceType) {
		//Note: we check _comps.isEmpty() only if device type diffs, because
		//a desktop might have several richlet and each of them will call
		//this method once
		if (!_devType.equals(deviceType)) {
			if (deviceType == null || deviceType.length() == 0)
				throw new IllegalArgumentException("empty");
			if (!Devices.exists(deviceType))
				throw new DeviceNotFoundException(deviceType, MZk.NOT_FOUND, deviceType);

			if (!_comps.isEmpty())
				throw new UiException("Unable to change the device type since some components are attached.");
			_devType = deviceType;
			_dev = null;

			((SessionCtrl)_sess).setDeviceType(_devType);
		}
	}
	public Execution getExecution() {
		return _exec;
	}
	public final Session getSession() {
		return _sess;
	}
	public String getUpdateURI(String pathInfo) {
		final String uri;
		if (pathInfo == null || pathInfo.length() == 0) {
			uri = _updateURI;
		} else {
			if (pathInfo.charAt(0) != '/')
				pathInfo = '/' + pathInfo;
			uri = _updateURI + pathInfo;
		}
		return _exec.encodeURL(uri);
	}
	public String getDynamicMediaURI(Component comp, String pathInfo) {
		if (!(((ComponentCtrl)comp).getExtraCtrl() instanceof DynamicMedia))
			throw new UiException(DynamicMedia.class+" not implemented by getExtraCtrl() of "+comp);

		final StringBuffer sb = new StringBuffer(64)
			.append("/view/").append(getId())
			.append('/').append(comp.getUuid());

		if (pathInfo != null && pathInfo.length() > 0) {
			if (!pathInfo.startsWith("/")) sb.append('/');
			sb.append(pathInfo);
		}
		return getUpdateURI(sb.toString());
	}
	public String getDownloadMediaURI(Media media, String pathInfo) {
		if (media == null)
			throw new IllegalArgumentException("null media");

		if (_meds == null) {
			_meds = new CacheMap();
			_meds.setMaxSize(1024 * 16);
			_meds.setLifetime(6 * 60 * 1000);
				//6 minutes (CONSIDER: configurable)
		}
		String medId = Strings.encode(
			new StringBuffer(12).append(MEDIA_PREFIX), _medId++).toString();
		_meds.put(medId, media);

		final StringBuffer sb = new StringBuffer(64)
			.append("/view/").append(getId())
			.append('/').append(medId);

		if (pathInfo != null && pathInfo.length() > 0) {
			if (!pathInfo.startsWith("/")) sb.append('/');
			sb.append(pathInfo);
		}
		return getUpdateURI(sb.toString());
	}
	public Media getDownloadMedia(String medId, boolean remove) {
		return _meds != null ? remove ?
			(Media)_meds.remove(medId): (Media)_meds.get(medId): null;
	}

	public Page getPage(String pageId) {
		//We allow user to access this method concurrently, so synchronized
		//is required
		final Page page = getPageIfAny(pageId);
		if (page == null)
			throw new ComponentNotFoundException("Page not found: "+pageId);
		return page;
	}
	public Page getPageIfAny(String pageId) {
		synchronized (_pages) {
			return (Page)_pages.get(pageId);
		}
	}
	public boolean hasPage(String pageId) {
		return _pages.containsKey(pageId);
	}
	public Collection getPages() {
		//No synchronized is required because it cannot be access concurrently
		return _pages.values();
	}

	public String getBookmark() {
		return _bookmark;
	}
	public void setBookmark(String name) {
		if (_exec == null)
			throw new IllegalStateException("Not the current desktop: "+this);
		if (name.indexOf('#') >= 0 || name.indexOf('?') >= 0)
			throw new IllegalArgumentException("Illegal character: # ?");
		_bookmark = name;
		((WebAppCtrl)_wapp).getUiEngine()
			.addResponse("bookmark", new AuBookmark(name));
	}