Java tutorial
/* ############################################################################### # # # Copyright 2016, AdeptJ (http://www.adeptj.com) # # # # 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 com.adeptj.runtime.common; import com.adeptj.runtime.osgi.BridgeHttpSessionAttributeListener; import com.adeptj.runtime.osgi.BridgeHttpSessionIdListener; import com.adeptj.runtime.osgi.BridgeHttpSessionListener; import com.adeptj.runtime.osgi.BridgeServletContextAttributeListener; import com.adeptj.runtime.servlet.BridgeServlet; import org.apache.commons.lang3.ArrayUtils; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceRegistration; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.servlet.Servlet; import javax.servlet.ServletContext; import javax.servlet.ServletRegistration; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import java.util.Dictionary; import java.util.EventListener; import java.util.Hashtable; import java.util.List; import java.util.Optional; import java.util.stream.Stream; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_ASYNC_SUPPORTED; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_ERROR_PAGE; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_INIT_PARAM_PREFIX; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_NAME; import static org.osgi.service.http.whiteboard.HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_PATTERN; /** * Utility for servlet, filters and listeners * * @author Rakesh.Kumar, AdeptJ */ public class Servlets { private static final Logger LOGGER = LoggerFactory.getLogger(Servlets.class); private static final String BRIDGE_SERVLET = "AdeptJ BridgeServlet"; private static final String ROOT_MAPPING = "/"; private static final String ALL_CONTEXT_SELECT_FILTER = "(osgi.http.whiteboard.context.name=*)"; private Servlets() { } public static void registerListener(ServletContext servletContext, EventListener listener) { servletContext.addListener(listener); } public static void registerListeners(ServletContext servletContext, List<EventListener> listeners) { listeners.forEach(servletContext::addListener); } public static void registerBridgeListeners(ServletContext servletContext) { servletContext.addListener(new BridgeServletContextAttributeListener()); servletContext.addListener(new BridgeHttpSessionListener()); servletContext.addListener(new BridgeHttpSessionIdListener()); servletContext.addListener(new BridgeHttpSessionAttributeListener()); } public static void registerBridgeServlet(ServletContext context) { // Register the BridgeServlet after the OSGi Framework started successfully. // This will ensure that the Felix DispatcherServlet is available as an OSGi service and can be tracked. // BridgeServlet delegates all the service calls to the Felix DispatcherServlet. ServletRegistration.Dynamic bridgeServlet = context.addServlet(BRIDGE_SERVLET, new BridgeServlet()); bridgeServlet.addMapping(ROOT_MAPPING); // Required if [osgi.http.whiteboard.servlet.asyncSupported] is declared true for OSGi HttpService managed Servlets. // Otherwise the request processing fails throwing exception. // [java.lang.IllegalStateException: UT010026: Async is not supported for this request, as not all filters or Servlets // were marked as supporting async] bridgeServlet.setAsyncSupported(true); // Load early to detect any issue with OSGi Felix DispatcherServlet initialization. bridgeServlet.setLoadOnStartup(0); } public static ServiceRegistration<Servlet> osgiServlet(BundleContext ctx, HttpServlet servlet) { Class<? extends HttpServlet> cls = servlet.getClass(); WebServlet webServlet = checkWebServletAnnotation(cls); Dictionary<String, Object> properties = new Hashtable<>(); // NOSONAR properties.put(HTTP_WHITEBOARD_SERVLET_PATTERN, ArrayUtils.isEmpty(webServlet.urlPatterns()) ? webServlet.value() : webServlet.urlPatterns()); properties.put(HTTP_WHITEBOARD_SERVLET_ASYNC_SUPPORTED, webServlet.asyncSupported()); handleInitParams(webServlet, properties); String servletName = resolveServletName(cls, webServlet.name(), properties); LOGGER.info("Registering OSGi Servlet: [{}]", servletName); return ctx.registerService(Servlet.class, servlet, properties); } public static ServiceRegistration<Servlet> osgiServlet(BundleContext ctx, HttpServlet errorServlet, List<String> errors) { Class<? extends HttpServlet> cls = errorServlet.getClass(); WebServlet webServlet = checkWebServletAnnotation(cls); Dictionary<String, Object> properties = new Hashtable<>(); // NOSONAR properties.put(HTTP_WHITEBOARD_SERVLET_ERROR_PAGE, errors); // Apply this ErrorServlet to all the ServletContext instances registered with OSGi. properties.put(HTTP_WHITEBOARD_CONTEXT_SELECT, ALL_CONTEXT_SELECT_FILTER); properties.put(HTTP_WHITEBOARD_SERVLET_ASYNC_SUPPORTED, webServlet.asyncSupported()); handleInitParams(webServlet, properties); String servletName = resolveServletName(cls, webServlet.name(), properties); LOGGER.info("Registering OSGi ErrorServlet: [{}]", servletName); return ctx.registerService(Servlet.class, errorServlet, properties); } private static WebServlet checkWebServletAnnotation(Class<? extends HttpServlet> cls) { return Optional.ofNullable(cls.getAnnotation(WebServlet.class)).orElseThrow( () -> new IllegalArgumentException("Can't register a servlet without @WebServlet annotation!!")); } private static void handleInitParams(WebServlet webServlet, Dictionary<String, Object> properties) { Stream.of(webServlet.initParams()).forEach(initParam -> properties .put(HTTP_WHITEBOARD_SERVLET_INIT_PARAM_PREFIX + initParam.name(), initParam.value())); } private static String resolveServletName(Class<? extends HttpServlet> cls, String name, Dictionary<String, Object> props) { String servletName = name.isEmpty() ? cls.getSimpleName() : name; props.put(HTTP_WHITEBOARD_SERVLET_NAME, servletName); return servletName; } }