/* DHtmlLayoutFilter.java
Purpose:
Description:
History:
Wed Nov 30 00:49:59 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 javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zkoss.lang.Strings;
import org.zkoss.web.servlet.Servlets;
import org.zkoss.web.servlet.http.HttpBufferedResponse;
import org.zkoss.web.servlet.http.Https;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.Session;
import org.zkoss.zk.ui.UiException;
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.sys.RequestInfo;
import org.zkoss.zk.ui.sys.SessionCtrl;
import org.zkoss.zk.ui.sys.UiFactory;
import org.zkoss.zk.ui.sys.WebAppCtrl;
/**
* Used to post-process the response into a ZK page.
* It is useful if you have a servlet using servlets, JSP or other
* technology.
*
* <p>How to use:
* <ul>
* <li>Decorates the servlet to embed the ZK components and
* attributes, such as zk:onClick="...".</li>
* <li>Maps the servlet to the filter in web.xml</li>
* </ul>
*
* @author tomyeh
*/
public class DHtmlLayoutFilter implements Filter {
private static final Logger log = LoggerFactory.getLogger(DHtmlLayoutFilter.class);
private ServletContext _ctx;
private String _ext = "html";
private String _charset = "UTF-8";
private boolean _compress = true;
/** Processes the content
* @since 3.0.0
*/
protected void process(HttpServletRequest request, HttpServletResponse response, String content)
throws ServletException, IOException {
if (log.isDebugEnabled())
log.debug("Content to filter:\n" + content);
final WebManager webman = WebManager.getWebManager(_ctx);
final WebApp wapp = webman.getWebApp();
final WebAppCtrl wappc = (WebAppCtrl) wapp;
final Session sess = webman.getSession(_ctx, request);
final Object old = I18Ns.setup(sess, request, response, _charset);
try {
final String path = Https.getThisServletPath(request);
final Desktop desktop = webman.getDesktop(sess, request, response, path, true);
if (desktop == null) //forward or redirect
return;
final RequestInfo ri = new RequestInfoImpl(wapp, sess, desktop, request, null);
((SessionCtrl) sess).notifyClientRequest(true);
final UiFactory uf = wappc.getUiFactory();
final PageDefinition pagedef = uf.getPageDefinitionDirectly(ri, content, _ext);
final Page page = WebManager.newPage(uf, ri, pagedef, response, path);
final Execution exec = new ExecutionImpl(_ctx, request, response, desktop, page);
final StringWriter out = new StringWriter(4096 * 2);
wappc.getUiEngine().execNewPage(exec, pagedef, page, out);
//bug 1738368: Jetty refuses wrong content length
//so we have to calculate it again here
//(Note: we have to set content length since the servlet
//being filtering might set content-length, which is,
//of course, wrong
String cs = response.getCharacterEncoding();
if (cs == null || cs.length() == 0)
cs = _charset != null ? _charset : "UTF-8";
final String result = out.toString();
try {
final OutputStream os = response.getOutputStream();
//Call it first to ensure getWrite() is not called yet
byte[] data = result.getBytes(cs);
if (_compress && !Servlets.isIncluded(request) && 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);
} catch (IllegalStateException ex) { //getWriter was called
response.getWriter().write(result);
}
} catch (UiException ex) {
log.error("Failed to process:\n" + content);
throw ex;
} finally {
I18Ns.cleanup(request, old);
}
}
/** Filters the content to make it legal XML if possible.
* Currently, it only removes <!DOCTYPE ...//DTD HTML...>,
* since it makes it invalid XML. Refer to Bug 1702216.
*
* <p>Note: we cannot remove all DOCTYPE. Refer to Bug 1720620.
*/
private static String xmlfilter(StringBuffer sb) {
for (int j = 0, len = sb.length(); j < len; ++j) {
char cc = sb.charAt(j);
if (cc == '<') {
if (++j < len && sb.charAt(j) == '!') {
j = Strings.skipWhitespaces(sb, j + 1);
if (j + 7 < len && "DOCTYPE".equalsIgnoreCase(sb.substring(j, j + 7))) {
for (int k = j += 7; k < len; ++k) {
if (sb.charAt(k) == '>') {
if (shallFilter(sb.substring(j, k)))
return sb.substring(k + 1);
break;
}
}
}
}
break;
}
}
return sb.toString();
}
private static boolean shallFilter(String pubId) {
pubId = pubId.toUpperCase();
int j = pubId.indexOf("//DTD");
if (j >= 0) {
j = Strings.skipWhitespaces(pubId, j + 5);
return j + 4 < pubId.length() && "HTML".equals(pubId.substring(j, j + 4));
}
return false; //unknown => don't filter out (safer)
}
//-- Filter --//
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
final StringWriter sw = new StringWriter(4096 * 2);
final HttpServletResponse hres = (HttpServletResponse) response;
final HttpBufferedResponse hbufres = (HttpBufferedResponse) HttpBufferedResponse.getInstance(hres, sw);
chain.doFilter(request, hbufres);
//Bug 1673839: servlet might redirect
if (!hbufres.isSendRedirect())
process((HttpServletRequest) request, hres, xmlfilter(sw.getBuffer()));
}
public void destroy() {
}
public final void init(FilterConfig config) throws ServletException {
_ctx = config.getServletContext();
String param = config.getInitParameter("extension");
if (param != null && param.length() > 0)
_ext = param;
param = config.getInitParameter("charset");
if (param != null)
_charset = param.length() > 0 ? param : null;
param = config.getInitParameter("compress");
if (param != null)
_compress = "true".equals(param);
}
}