org.ajax4jsf.framework.resource.InternetResourceBuilder Maven / Gradle / Ivy

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Ajax4jsf is an open source extension to the JavaServer Faces standard that adds AJAX capability to JSF applications without requiring the writing of any JavaScript.
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/**
 * Licensed under the Common Development and Distribution License,
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.sun.com/cddl/
 *   
 * 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.ajax4jsf.framework.resource;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.faces.FacesException;
import javax.faces.context.FacesContext;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public abstract class InternetResourceBuilder {

	protected static Log log = LogFactory.getLog(InternetResourceBuilder.class);

	/**
	 * Get application start time for check resources modification time.
	 * @return application start time in msec's
	 */
	public abstract long getStartTime();

	/**
	 * @param cacheable
	 * @param session
	 * @param mime
	 * @return
	 * @throws FacesException
	 */
	public abstract InternetResource createUserResource(boolean cacheable,
			boolean session, String mime) throws FacesException;

	/**
	 * @param request
	 * @return
	 */
	public abstract String getFacesResourceKey(HttpServletRequest request);

	/**
	 * @param key
	 * @param resource
	 */
	public abstract void addResource(String key, InternetResource resource);

	/**
	 * @param path
	 * @return
	 * @throws ResourceNotFoundException
	 */
	public abstract InternetResource getResource(String path)
			throws ResourceNotFoundException;

	/**
	 * @param key
	 * @return
	 */
	public abstract Object getResourceDataForKey(String key);

	/**
	 * @param key
	 * @return
	 * @throws ResourceNotFoundException
	 */
	public abstract InternetResource getResourceForKey(String key)
			throws ResourceNotFoundException;

	/**
	 * @param resource
	 * @param context
	 * @param storeData
	 * @return
	 */
	public abstract String getUri(InternetResource resource,
			FacesContext context, Object storeData);

	/**
	 * @param base
	 * @param path
	 * @return
	 * @throws FacesException
	 */
	public abstract InternetResource createResource(Object base, String path)
			throws FacesException;

	/**
	 * @param servletContext
	 * @param filterName
	 * @throws ServletException
	 */
	public abstract void init(ServletContext servletContext, String filterName)
			throws ServletException;

	/**
	 * static instance variable.
	 */
	private static Map instances = Collections.synchronizedMap(new HashMap());

	/**
	 * Get ( or create if nessesary ) instance of builder for current loader.
	 * check content of file META-INF/services/org.ajax4jsf.framework.resource.InternetResourceBuilder for
	 * name of class to instantiate, othrthise create {@link ResourceBuilderImpl} instance.
	 * @return current builder instance.
	 */
	public static InternetResourceBuilder getInstance() {
		ClassLoader loader = Thread.currentThread().getContextClassLoader();
		InternetResourceBuilder instance = (InternetResourceBuilder) instances
				.get(loader);
		if (null == instance) {
			try {
				String resource = "META-INF/services/"
						+ InternetResourceBuilder.class.getName();
				InputStream in = loader.getResourceAsStream(resource);
				BufferedReader reader = new BufferedReader(
						new InputStreamReader(in));
				String serviceClassName = reader.readLine();
				reader.close();
				Class builderClass = loader.loadClass(serviceClassName);
				instance = (InternetResourceBuilder) builderClass.newInstance();
				if (log.isDebugEnabled()) {
					log.debug("Create instance of InternetBuilder from class "
							+ serviceClassName);
				}
			} catch (Exception e) {
				if (log.isDebugEnabled()) {
					log
							.debug(
									"Create default implementation instance of InternetBuilder");
				}
				instance = new ResourceBuilderImpl();
			}
			instances.put(loader, instance);
		}
		return instance;
	}

	/**
	 * Package-wide method for reset instance in Junit tests.
	 * 
	 * @param instance
	 */
	public static void setInstance(InternetResourceBuilder instance) {
		ClassLoader loader = Thread.currentThread().getContextClassLoader();
		instances.put(loader, instance);
	}

	public InternetResourceBuilder() {
		super();
	}

}