org.springframework.faces.webflow.JsfAjaxHandler Maven / Gradle / Ivy
/*
* Copyright 2004-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.faces.webflow;
import java.io.IOException;
import java.io.Writer;
import javax.faces.FactoryFinder;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.context.PartialResponseWriter;
import javax.faces.context.ResponseWriter;
import javax.faces.render.RenderKit;
import javax.faces.render.RenderKitFactory;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.js.ajax.AbstractAjaxHandler;
/**
* Ajax handler for JSF 2 requests that can identify JSF 2 Ajax requests and send redirect instructions back to the
* client by including a redirect instruction in the content of the response.
*
* @see AbstractAjaxHandler
*
* @author Rossen Stoyanchev
* @since 2.2.0
*/
public class JsfAjaxHandler extends AbstractAjaxHandler {
public JsfAjaxHandler() {
this(null);
}
public JsfAjaxHandler(AbstractAjaxHandler delegate) {
super(delegate);
}
protected boolean isAjaxRequestInternal(HttpServletRequest request, HttpServletResponse response) {
String facesRequestHeader = request.getHeader("Faces-Request");
return ("partial/ajax".equals(facesRequestHeader)) ? true : false;
}
protected void sendAjaxRedirectInternal(final String targetUrl, final HttpServletRequest request,
final HttpServletResponse response, boolean popup) throws IOException {
// Ideally facesContext.getExternalContext().redirect() should be used instead of the code in this method.
// However PartialViewContextImpl.createPartialResponseWriter() calls cxt.getRenderKit(), which in turn
// tries to get the UIViewRoot's renderKitId. That results in NPE when JsfAjaxHandler is called
// outside of flow execution. The code below wraps the FacesContext to override getRenderKit() and provide a
// default render kit id.
FacesContextHelper helper = new FacesContextHelper();
try {
FacesContext facesContext = helper.getFacesContext(getServletContext(), request, response);
PartialResponseWriter writer = createPartialResponseWriter(facesContext);
writer.startDocument();
writer.redirect(targetUrl);
writer.endDocument();
} finally {
helper.releaseIfNecessary();
}
}
private PartialResponseWriter createPartialResponseWriter(FacesContext context) throws IOException {
ExternalContext externalContext = context.getExternalContext();
String encoding = externalContext.getRequestCharacterEncoding();
externalContext.setResponseCharacterEncoding(encoding);
ResponseWriter responseWriter = null;
Writer out = externalContext.getResponseOutputWriter();
if (out != null) {
RenderKitFactory factory = (RenderKitFactory) FactoryFinder.getFactory(FactoryFinder.RENDER_KIT_FACTORY);
RenderKit renderKit = factory.getRenderKit(context, RenderKitFactory.HTML_BASIC_RENDER_KIT);
responseWriter = renderKit.createResponseWriter(out, "text/xml", encoding);
}
if (responseWriter instanceof PartialResponseWriter) {
return (PartialResponseWriter) responseWriter;
} else {
return new PartialResponseWriter(responseWriter);
}
}
}