dhtmllayoutservlet.java

非常接近C/S操作方式的Java Ajax框架－ZK 用ZK框架使你的B/S应用程序更漂亮更易操作。 官网：www.zkoss.org

/* DHtmlLayoutServlet.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Mon May 30 21:11:28     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.http;

import java.util.Map;
import java.util.HashMap;
import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpSession;

import org.zkoss.mesg.Messages;
import org.zkoss.lang.D;
import org.zkoss.util.logging.Log;

import org.zkoss.web.Attributes;
import org.zkoss.web.servlet.Servlets;
import org.zkoss.web.servlet.http.Https;

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.Session;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Richlet;
import org.zkoss.zk.ui.metainfo.PageDefinition;
import org.zkoss.zk.ui.metainfo.PageDefinitions;
import org.zkoss.zk.ui.sys.UiFactory;
import org.zkoss.zk.ui.sys.RequestInfo;
import org.zkoss.zk.ui.sys.WebAppCtrl;
import org.zkoss.zk.ui.impl.RequestInfoImpl;

/**
 * Used to process the request for a ZUML page. Though it is called
 * DHtmlLayoutServlet, it is used to serve all kind of HTTP-based clients,
 * including html, mul and others (see {@link Desktop#getClientType}.
 *
 * @author tomyeh
 */
public class DHtmlLayoutServlet extends HttpServlet {
	private static final Log log = Log.lookup(DHtmlLayoutServlet.class);
	private ServletContext _ctx;
	private WebManager _webman;

	public void init(ServletConfig config) throws ServletException {
		//super.init(config);
			//Note callback super to avoid saving config

		_ctx = config.getServletContext();
		if (WebManager.getWebManagerIfAny(_ctx) != null)
			throw new ServletException("Only one layout servlet is allowed in one context: "+_ctx);

		String updateURI = config.getInitParameter("update-uri");
		if (updateURI == null
		|| (updateURI = updateURI.trim()).length() == 0
		|| updateURI.charAt(0) != '/')
			throw new ServletException("The update-uri parameter must be specified and starts with /");
		if (updateURI.indexOf(';') >= 0 || updateURI.indexOf('?') >= 0)
			throw new ServletException("The update-uri parameter cannot contain ';' or '?'");
			//Jetty will encode URL by appending ';jsess..' and we have to
			//remove it under certain situations, so not alow it
		if (updateURI.charAt(updateURI.length() - 1) == '\\') {
			if (updateURI.length() == 1)
				throw new ServletException("The update-uri parameter cannot contain only '/'");
			updateURI = updateURI.substring(0, updateURI.length() - 1);
				//remove the trailing '\\' if any
		}

		_webman = new WebManager(_ctx, updateURI);
	}
	public void destroy() {
		if (_webman != null) _webman.destroy();
	}
	public ServletContext getServletContext() {
		return _ctx;
	}

	//-- super --//
	protected
	void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		final Session sess = WebManager.getSession(getServletContext(), request);
		final Object old = I18Ns.setup(sess, request, response,
			sess.getWebApp().getConfiguration().getCharset());
		try {
			process(sess, request, response);
		} finally {
			I18Ns.cleanup(request, old);
		}
	}
	protected
	void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		doGet(request, response);
	}

	//-- private --//
	private void process(Session sess,
	HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		final String pi = Https.getThisPathInfo(request);
		final String path = pi != null && pi.length() > 0 ?
			pi: Https.getThisServletPath(request);
		if (D.ON && log.finerable()) log.finer("Creates from "+path+", "+pi);

		final WebApp wapp = _webman.getWebApp();
		final WebAppCtrl wappc = (WebAppCtrl)wapp;
		final Desktop desktop = _webman.getDesktop(sess, request, path);
		final RequestInfo ri = new RequestInfoImpl(
			wapp, sess, desktop, request,
			PageDefinitions.getLocator(wapp, path));
		final UiFactory uf = wappc.getUiFactory();

		if (pi != null) {
			final Richlet richlet = wapp.getConfiguration().getRichlet(pi);
			if (richlet == null) {
				sendError(request, response, pi);
				return;
			}

			final Page page = uf.newPage(ri, richlet, pi);
			final Execution exec = new ExecutionImpl(
				_ctx, request, response, desktop, page);
			wappc.getUiEngine().execNewPage(exec, richlet, page, response.getWriter());
				//no need to set client type here, since UiEngine will do it later
		} else {
			final PageDefinition pagedef = uf.getPageDefinition(ri, path);
			if (pagedef == null) {
				sendError(request, response, path);
				return;
			}

			final Page page = uf.newPage(ri, pagedef, path);
			final Execution exec = new ExecutionImpl(
				_ctx, request, response, desktop, page);
			wappc.getUiEngine()
				.execNewPage(exec, pagedef, page, response.getWriter());
		}
	}
	private void sendError(HttpServletRequest request, HttpServletResponse response,
	String path) throws ServletException, IOException {
		if (Servlets.isIncluded(request)) {
			final String msg = Messages.get(MZk.PAGE_NOT_FOUND,
				new Object[] {path});
			final Map attrs = new HashMap();
			attrs.put(Attributes.ALERT_TYPE, "error");
			attrs.put(Attributes.ALERT, msg);
			Servlets.include(_ctx, request, response,
				"~./html/alert.dsp", attrs, Servlets.PASS_THRU_ATTR);
		} else {
			response.sendError(HttpServletResponse.SC_NOT_FOUND);
		}
	}
}