Java tutorial
/** * Copyright 2010 Marko Lavikainen * * 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 net.contextfw.web.application.internal.service; import java.io.IOException; import java.util.Date; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.contextfw.web.application.ResourceCleaner; import net.contextfw.web.application.WebApplicationException; import net.contextfw.web.application.component.Component; import net.contextfw.web.application.configuration.Configuration; import net.contextfw.web.application.internal.component.MetaComponentException; import net.contextfw.web.application.internal.development.InternalDevelopmentTools; import net.contextfw.web.application.internal.page.PageScope; import net.contextfw.web.application.internal.page.WebApplicationPage; import net.contextfw.web.application.internal.servlet.UriMapping; import net.contextfw.web.application.lifecycle.LifecycleListener; import net.contextfw.web.application.remote.ErrorResolution; import net.contextfw.web.application.scope.ScopedWebApplicationExecution; import net.contextfw.web.application.scope.WebApplicationStorage; import org.apache.commons.lang.mutable.MutableBoolean; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.inject.Inject; import com.google.inject.Provider; public class InitHandler { private Logger logger = LoggerFactory.getLogger(InitHandler.class); private static final long HOUR = 1000 * 60 * 3600; @Inject private Provider<WebApplication> webApplicationProvider; @Inject private LifecycleListener listeners; private PageScope pageScope; @Inject private WebApplicationStorage storage; private final long initialMaxInactivity; private DirectoryWatcher watcher; private ResourceCleaner cleaner; private final boolean developmentMode; private final InternalDevelopmentTools internalDevelopmentTools; public InitHandler(Configuration properties, PageScope pageScope, InternalDevelopmentTools internalDevelopmentTools) { initialMaxInactivity = properties.get(Configuration.INITIAL_MAX_INACTIVITY); developmentMode = properties.get(Configuration.DEVELOPMENT_MODE); this.pageScope = pageScope; this.internalDevelopmentTools = internalDevelopmentTools; } public final void handleRequest(final UriMapping mapping, final List<Class<? extends Component>> chain, final HttpServlet servlet, final HttpServletRequest request, final HttpServletResponse response) throws ServletException, IOException { if (watcher != null && watcher.hasChanged()) { logger.debug("Reloading resources"); cleaner.clean(); internalDevelopmentTools.reloadResources(); } response.addHeader("Expires", "Sun, 19 Nov 1978 05:00:00 GMT"); response.addHeader("Last-Modified", new Date().toString()); response.addHeader("Cache-Control", "no-store, no-cache, must-revalidate"); response.addHeader("Cache-Control", "post-check=0, pre-check=0"); response.addHeader("Pragma", "no-cache"); if (chain == null) { response.sendError(HttpServletResponse.SC_NOT_FOUND); } else { WebApplicationPage page = pageScope.createPage(servlet, request, response); final MutableBoolean expired = new MutableBoolean(false); storage.initialize(page, request, System.currentTimeMillis() + HOUR, new ScopedWebApplicationExecution() { @Override public void execute(net.contextfw.web.application.WebApplication application) { try { WebApplicationPage page = (WebApplicationPage) application; WebApplication app = webApplicationProvider.get(); app.setInitializerChain(chain); page.setWebApplication(app); listeners.beforeInitialize(); page.getWebApplication().initState(mapping); listeners.afterInitialize(); listeners.beforeRender(); expired.setValue(page.getWebApplication().sendResponse()); listeners.afterRender(); } catch (Exception e) { // TODO Fix this construct with test if (e instanceof MetaComponentException) { ErrorResolution resolution = ((MetaComponentException) e).getResolution(); try { if (resolution == ErrorResolution.SEND_NOT_FOUND_ERROR) { response.sendError(HttpServletResponse.SC_NOT_FOUND); } else if (resolution == ErrorResolution.SEND_BAD_REQUEST_ERROR) { response.sendError(HttpServletResponse.SC_BAD_REQUEST); } } catch (IOException e1) { throw new WebApplicationException(e1); } } listeners.onException(e); } finally { pageScope.deactivateCurrentPage(); } } }); // Setting expiration here so that long page // processing is // not // penalizing client if (expired.booleanValue()) { storage.remove(page.getHandle(), request); } else { storage.refresh(page.getHandle(), request, System.currentTimeMillis() + initialMaxInactivity); } } } @Inject public void setWatcher(DirectoryWatcher watcher) { if (developmentMode) { this.watcher = watcher; } } @Inject public void setCleaner(ResourceCleaner cleaner) { if (developmentMode) { this.cleaner = cleaner; } } public void setPageScope(PageScope pageScope) { this.pageScope = pageScope; } }