org.richfaces.util.RenderPhaseComponentVisitorUtils.java Source code

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Here is the source code for org.richfaces.util.RenderPhaseComponentVisitorUtils.java

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/**
 * License Agreement.
 *
 * Rich Faces - Natural Ajax for Java Server Faces (JSF)
 *
 * Copyright (C) 2007 Exadel, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */
package org.richfaces.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.Map;

import javax.faces.FacesException;
import javax.faces.context.FacesContext;

import org.ajax4jsf.resource.util.URLToStreamHelper;
import org.ajax4jsf.util.ServicesUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.richfaces.event.RenderPhaseComponentVisitor;

public class RenderPhaseComponentVisitorUtils {

    private static final Log log = LogFactory.getLog(RenderPhaseComponentVisitorUtils.class);

    private static final String KEY = RenderPhaseComponentVisitorUtils.class.getName();

    private RenderPhaseComponentVisitorUtils() {
    }

    public static RenderPhaseComponentVisitor[] getVisitors(FacesContext context) {
        Map<String, Object> applicationMap = context.getExternalContext().getApplicationMap();
        RenderPhaseComponentVisitor[] visitors;
        synchronized (applicationMap) {
            visitors = (RenderPhaseComponentVisitor[]) applicationMap.get(KEY);
            if (visitors == null) {
                visitors = init();
                applicationMap.put(KEY, visitors);
            }
        }
        return visitors;
    }

    private static RenderPhaseComponentVisitor[] init() {
        LinkedList<RenderPhaseComponentVisitor> list = new LinkedList<RenderPhaseComponentVisitor>();
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        String resource = "META-INF/services/org.richfaces.component.RenderPhaseComponentVisitor";
        try {
            Enumeration<URL> resources = loader.getResources(resource);
            while (resources.hasMoreElements()) {
                InputStream stream = URLToStreamHelper.urlToStreamSafe(resources.nextElement());
                BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
                try {
                    String handlerClassName = null;
                    while ((handlerClassName = reader.readLine()) != null) {
                        if (handlerClassName.length() > 0) {
                            try {
                                Class<?> handlerClass = ServicesUtils.loadClass(loader, handlerClassName);
                                Object handler = handlerClass.newInstance();
                                list.add((RenderPhaseComponentVisitor) handler);
                            } catch (Exception e) {
                                throw new FacesException("Error create instance for class " + handlerClassName, e);
                            }
                        }
                    }

                } finally {
                    try {
                        reader.close();
                    } catch (IOException e) {
                        if (log.isDebugEnabled()) {
                            log.debug(e.getLocalizedMessage(), e);
                        }
                    }
                }
            }
        } catch (IOException e) {
            throw new FacesException("Error load resource " + resource, e);
        }
        return list.toArray(new RenderPhaseComponentVisitor[list.size()]);
    }
}