| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.sling.distribution.servlet; |
| |
| import javax.annotation.Nonnull; |
| import javax.annotation.Nullable; |
| import javax.servlet.ServletException; |
| import java.io.IOException; |
| import java.io.PrintWriter; |
| import java.util.Arrays; |
| |
| import org.apache.felix.scr.annotations.sling.SlingServlet; |
| import org.apache.sling.api.SlingHttpServletRequest; |
| import org.apache.sling.api.SlingHttpServletResponse; |
| import org.apache.sling.api.resource.ResourceResolver; |
| import org.apache.sling.api.servlets.SlingAllMethodsServlet; |
| import org.apache.sling.distribution.DistributionRequest; |
| import org.apache.sling.distribution.common.DistributionException; |
| import org.apache.sling.distribution.component.impl.DistributionComponentKind; |
| import org.apache.sling.distribution.resources.DistributionResourceTypes; |
| import org.apache.sling.distribution.trigger.DistributionRequestHandler; |
| import org.apache.sling.distribution.trigger.DistributionTrigger; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Triggers Server Sent Events servlet |
| */ |
| @SuppressWarnings("serial") |
| @SlingServlet(resourceTypes = DistributionResourceTypes.TRIGGER_RESOURCE_TYPE, extensions = "event", methods = "GET") |
| public class DistributionTriggerServlet extends SlingAllMethodsServlet { |
| |
| private final Logger log = LoggerFactory.getLogger(getClass()); |
| |
| private final static int DEFAULT_NUMBER_OF_SECONDS = 60; |
| private final static int MAX_NUMBER_OF_SECONDS = 3600; |
| |
| @Override |
| protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) |
| throws ServletException, IOException { |
| |
| String secondsParameter = request.getParameter("sec"); |
| |
| int seconds = secondsParameter != null && secondsParameter.length() > 0 ? Integer.parseInt(secondsParameter) : |
| DEFAULT_NUMBER_OF_SECONDS; |
| |
| if (seconds > MAX_NUMBER_OF_SECONDS) { |
| seconds = MAX_NUMBER_OF_SECONDS; |
| } else if (seconds < 0) { |
| seconds = DEFAULT_NUMBER_OF_SECONDS; |
| } |
| |
| DistributionTrigger distributionTrigger = request.getResource().adaptTo(DistributionTrigger.class); |
| |
| // setup SSE headers |
| response.setContentType("text/event-stream"); |
| response.setCharacterEncoding("UTF-8"); |
| response.setHeader("Cache-Control", "no-cache"); |
| response.setHeader("Connection", "keep-alive"); |
| |
| // needed to allow e.g. the JavaScript EventSource API to make a call from author to this server and listen for the events |
| // response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin")); // allowed origins should be explicitly configured |
| // response.setHeader("Access-Control-Allow-Credentials", "true"); |
| |
| final PrintWriter writer = response.getWriter(); |
| |
| DistributionRequestHandler distributionRequestHandler = new DistributionRequestHandler() { |
| public String getName() { |
| return DistributionTriggerServlet.this.getClass().getSimpleName(); |
| } |
| |
| public DistributionComponentKind getComponentKind() { |
| return null; // unknown |
| } |
| |
| public void handle(@Nullable ResourceResolver resourceResolver, @Nonnull DistributionRequest request) { |
| writeEvent(writer, request); |
| } |
| }; |
| try { |
| distributionTrigger.register(distributionRequestHandler); |
| |
| try { |
| Thread.sleep(seconds * 1000); |
| } catch (InterruptedException e) { |
| log.error("thread interrupted", e); |
| } |
| |
| distributionTrigger.unregister(distributionRequestHandler); |
| |
| } catch (DistributionException e) { |
| response.setStatus(400); |
| response.getWriter().write("error while (un)registering trigger " + e.toString()); |
| } |
| } |
| |
| /* Write a single server-sent event to the response stream for the given event and message */ |
| private void writeEvent(PrintWriter writer, DistributionRequest distributionRequest) { |
| |
| // write the event type (make sure to include the double newline) |
| writer.write("id: " + System.currentTimeMillis() + "\n"); |
| |
| // write the actual data |
| // this could be simple text or could be JSON-encoded text that the |
| // client then decodes |
| writer.write("data: " + distributionRequest.getRequestType() + " " + Arrays.toString(distributionRequest.getPaths()) + "\n\n"); |
| |
| // flush the buffers to make sure the container sends the bytes |
| writer.flush(); |
| log.debug("SSE event {} {}", new Object[]{distributionRequest.getRequestType(), distributionRequest.getPaths()}); |
| } |
| } |