org.zkoss.zk.ui.http.DHtmlLayoutServlet Maven / Gradle / Ivy
/* DHtmlLayoutServlet.java
Purpose:
Description:
History:
Mon May 30 21:11:28 2005, Created by tomyeh
Copyright (C) 2005 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under LGPL Version 2.1 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui.http;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringWriter;
import java.io.Writer;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.LoggerFactory;
import org.zkoss.lang.Exceptions;
import org.zkoss.mesg.Messages;
import org.zkoss.web.servlet.Servlets;
import org.zkoss.web.servlet.http.Https;
import org.zkoss.zk.mesg.MZk;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.Richlet;
import org.zkoss.zk.ui.Session;
import org.zkoss.zk.ui.WebApp;
import org.zkoss.zk.ui.impl.RequestInfoImpl;
import org.zkoss.zk.ui.metainfo.PageDefinition;
import org.zkoss.zk.ui.metainfo.PageDefinitions;
import org.zkoss.zk.ui.sys.RequestInfo;
import org.zkoss.zk.ui.sys.SessionCtrl;
import org.zkoss.zk.ui.sys.SessionsCtrl;
import org.zkoss.zk.ui.sys.UiFactory;
import org.zkoss.zk.ui.sys.WebAppCtrl;
import org.zkoss.zk.ui.util.Configuration;
import org.zkoss.zk.ui.util.DesktopRecycle;
/**
* 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 ajax (HTML+Ajax), mil (Mobile Interactive Language)
* and others (see {@link Desktop#getDeviceType}.
*
* Init parameters:
*
*
* - update-uri
* - It specifies the URI which the ZK AU engine is mapped to.
* - compress
* - It specifies whether to compress the output if the browser supports the compression (Accept-Encoding) and this Servlet is not included by other Servlets.
* - log-level
* - It specifies the default log level for org.zkoss. If not specified, the system default (usually INFO) is used.
*
* @author tomyeh
*/
public class DHtmlLayoutServlet extends HttpServlet {
private static final org.slf4j.Logger log = LoggerFactory.getLogger(DHtmlLayoutServlet.class);
private WebManager _webman;
private boolean _webmanCreated;
private boolean _compress = true;
//Servlet//
@SuppressWarnings("deprecation")
public void init() throws ServletException {
final ServletConfig config = getServletConfig();
String param = config.getInitParameter("log-level");
if (param != null && param.length() > 0) {
final Level level = org.zkoss.util.logging.Log.getLevel(param);
if (level != null)
Logger.getLogger("org.zkoss").setLevel(level);
else
log.error("Unknown log-level: " + param);
}
param = config.getInitParameter("compress");
_compress = param == null || param.length() == 0 || "true".equals(param);
final ServletContext ctx = getServletContext();
_webman = WebManager.getWebManagerIfAny(ctx);
String updateURI = Utils.checkUpdateURI(config.getInitParameter("update-uri"), "The update-uri parameter");
ctx.setAttribute("org.zkoss.zk.ui.http.update-uri", updateURI); //B65-ZK-1619
if (_webman == null) {
log.warn("WebManager not initialized. Please check if HttpSessionListener is configured properly.");
_webman = new WebManager(ctx, updateURI);
_webmanCreated = true;
} else {
_webman.setUpdateUri(updateURI);
}
}
public void destroy() {
if (_webman != null) {
if (_webmanCreated)
_webman.destroy();
_webman = null;
}
}
//-- super --//
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String path = Https.getThisPathInfo(request);
final boolean bRichlet = path != null && path.length() > 0;
if (!bRichlet)
path = Https.getThisServletPath(request);
// if (log.finerable()) log.finer("Creates from "+path);
final Session sess = WebManager.getSession(getServletContext(), request);
if (!SessionsCtrl.requestEnter(sess)) {
response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, Messages.get(MZk.TOO_MANY_REQUESTS));
return;
}
try {
final Object old = I18Ns.setup(sess, request, response,
sess.getWebApp().getConfiguration().getResponseCharset());
try {
if (!process(sess, request, response, path, bRichlet))
handleError(sess, request, response, path, null);
} catch (Throwable ex) {
handleError(sess, request, response, path, ex);
} finally {
I18Ns.cleanup(request, old);
}
} finally {
SessionsCtrl.requestExit(sess);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
//-- private --//
/**
* Process the request.
* @return false if the page is not found.
* @since 3.0.0
*/
protected boolean process(Session sess, HttpServletRequest request, HttpServletResponse response, String path,
boolean bRichlet) throws ServletException, IOException {
final WebApp wapp = sess.getWebApp();
final WebAppCtrl wappc = (WebAppCtrl) wapp;
final Configuration config = wapp.getConfiguration();
final boolean bInclude = Servlets.isIncluded(request);
final boolean compress = _compress && !bInclude;
final Writer out = compress ? (Writer) new StringWriter() : response.getWriter();
final DesktopRecycle dtrc = bInclude ? null : config.getDesktopRecycle();
final ServletContext ctx = getServletContext();
Desktop desktop = dtrc != null ? DesktopRecycles.beforeService(dtrc, ctx, sess, request, response, path) : null;
try {
if (desktop != null) { //recycle
final Page page = Utils.getMainPage(desktop);
if (page != null) {
final Execution exec = new ExecutionImpl(ctx, request, response, desktop, page);
WebManager.setDesktop(request, desktop);
wappc.getUiEngine().recycleDesktop(exec, page, out);
} else
desktop = null; //something wrong (not possible; just in case)
}
// check voided for ZK-2352: Executions.forward() will show IOException warning
boolean voided = false;
if (desktop == null) {
desktop = _webman.getDesktop(sess, request, response, path, true);
if (desktop == null) //forward or redirect
return true;
final RequestInfo ri = new RequestInfoImpl(wapp, sess, desktop, request,
PageDefinitions.getLocator(wapp, path));
((SessionCtrl) sess).notifyClientRequest(true);
final UiFactory uf = wappc.getUiFactory();
if (uf.isRichlet(ri, bRichlet)) {
final Richlet richlet = uf.getRichlet(ri, path);
if (richlet == null)
return false; //not found
final Page page = WebManager.newPage(uf, ri, richlet, response, path);
final Execution exec = new ExecutionImpl(ctx, request, response, desktop, page);
wappc.getUiEngine().execNewPage(exec, richlet, page, out);
//no need to set device type here, since UiEngine will do it later
} else {
final PageDefinition pagedef = uf.getPageDefinition(ri, path);
if (pagedef == null)
return false; //not found
final Page page = WebManager.newPage(uf, ri, pagedef, response, path);
final Execution exec = new ExecutionImpl(ctx, request, response, desktop, page);
wappc.getUiEngine().execNewPage(exec, pagedef, page, out);
voided = exec.isVoided();
}
}
// check voided to ignore the IOExecuption that caused by Executions.forward()
if (compress && !voided) {
final String result = ((StringWriter) out).toString();
try {
final OutputStream os = response.getOutputStream();
//Call it first to ensure getWrite() is not called yet
byte[] data = result.getBytes(config.getResponseCharset());
if (data.length > 200) {
byte[] bs = Https.gzip(request, response, null, data);
if (bs != null)
data = bs; //yes, browser support compress
}
response.setContentLength(data.length);
os.write(data);
response.flushBuffer();
} catch (IllegalStateException ex) { //getWriter is called
response.getWriter().write(result);
}
}
} finally {
if (dtrc != null)
DesktopRecycles.afterService(dtrc, desktop);
}
return true; //success
}
/** Handles exception being thrown when rendering a page.
* @param err the exception being throw. If null, it means the page
* is not found.
*/
private void handleError(Session sess, HttpServletRequest request, HttpServletResponse response, String path,
Throwable err) throws ServletException, IOException {
Utils.resetOwner();
//Note: if not included, it is handled by Web container
if (err != null && Servlets.isIncluded(request)) {
//Bug 1714094: we have to handle err, because Web container
//didn't allow developer to intercept errors caused by inclusion
final String errpg = sess.getWebApp().getConfiguration().getErrorPage(sess.getDeviceType(), err);
if (errpg != null) {
try {
request.setAttribute("javax.servlet.error.message", Exceptions.getMessage(err));
request.setAttribute("javax.servlet.error.exception", err);
request.setAttribute("javax.servlet.error.exception_type", err.getClass());
request.setAttribute("javax.servlet.error.status_code", new Integer(500));
if (process(sess, request, response, errpg, false))
return; //done
log.warn("The error page not found: " + errpg);
} catch (IOException ex) { //eat it (connection off)
} catch (Throwable ex) {
log.warn("Failed to load the error page: " + errpg, ex);
}
}
}
Utils.handleError(getServletContext(), request, response, path, err);
}
}