Java tutorial
/******************************************************************************* * AIOLOS - Framework for dynamic distribution of software components at runtime. * Copyright (C) 2014-2016 iMinds - IBCN - UGent * * This file is part of AIOLOS. * * AIOLOS is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * Contributors: * Tim Verbelen, Steven Bohez, Elias Deconinck *******************************************************************************/ package be.iminds.aiolos.ui; import java.io.IOException; import java.io.Writer; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.concurrent.ExecutionException; import java.util.concurrent.Future; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.osgi.framework.BundleContext; import org.osgi.resource.Capability; import org.osgi.resource.Requirement; import org.osgi.service.log.LogService; import org.osgi.service.repository.Repository; import be.iminds.aiolos.info.ComponentInfo; import be.iminds.aiolos.platform.api.PlatformManager; import be.iminds.aiolos.resource.CapabilityRequirementImpl; public class ComponentServlet extends CommonServlet { private static final long serialVersionUID = -6373378234336439591L; private static final String LABEL = "aiolos-components"; private static final String TITLE = "%aiolos.components.pluginTitle"; private static final String CATEGORY = "Aiolos"; private static final String CSS[] = { "/" + LABEL + "/res/ui/aiolos.css" }; private static final String TEMPLATE = "/templates/components.html"; public ComponentServlet(BundleContext context) { super(LABEL, TITLE, CATEGORY, CSS, TEMPLATE, context); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { final PlatformManager platformManager = platformTracker.getService(); final String action = (String) request.getParameter("action"); Activator.logger.log(LogService.LOG_DEBUG, "post request (" + action + ")"); Future<?> task = null; if (action != null) if (action.equals("scale")) { final String componentId = request.getParameter("component"); final String version = request.getParameter("version"); final int scaleCount = Integer.parseInt(request.getParameter("scaleCount")); final boolean forceNew = (request.getParameter("forceNew") != null); task = executor.submit(new Runnable() { @Override public void run() { try { platformManager.scaleComponent(componentId, version, scaleCount, forceNew); Activator.logger.log(LogService.LOG_INFO, "Scaled component " + componentId); } catch (Exception e) { Activator.logger.log(LogService.LOG_ERROR, "Error scaling component " + componentId + ": " + e.getLocalizedMessage(), e); } } }); } try { if (task != null) { task.get(); // result not important just wait. } renderJSON(response, request.getLocale()); } catch (InterruptedException e) { Activator.logger.log(LogService.LOG_ERROR, "Action interrupted: " + action, e); super.doPost(request, response); } catch (ExecutionException e) { Activator.logger.log(LogService.LOG_ERROR, "Action failed to execute: " + action, e); super.doPost(request, response); } } @SuppressWarnings("unchecked") @Override protected void writeJSON(Writer w, Locale locale) throws IOException { Collection<ComponentDescription> components = getComponentsInfo(); final Object[] status = getStatusLine(components); final JSONObject obj = new JSONObject(); JSONArray stat = new JSONArray(); for (int i = 0; i < status.length; i++) stat.add(status[i]); obj.put("status", stat); final JSONArray list = new JSONArray(); for (ComponentDescription component : components) { JSONObject jsonComponent = new JSONObject(); jsonComponent.put("id", component.componentId); jsonComponent.put("version", component.version); JSONArray jsonNodes = new JSONArray(); jsonNodes.addAll(component.nodes); jsonComponent.put("nodes", jsonNodes); list.add(jsonComponent); } obj.put("components", list); w.write(obj.toJSONString()); } private Object[] getStatusLine(Collection<ComponentDescription> components) { Object[] ret = new Object[1]; ret[0] = components.size(); return ret; } private Collection<ComponentDescription> getComponentsInfo() { Collection<ComponentDescription> components = new ArrayList<ComponentDescription>(); Repository[] repos = new Repository[] {}; repos = repositoryTracker.getServices(repos); for (Repository repo : repos) { try { CapabilityRequirementImpl requirement = new CapabilityRequirementImpl("osgi.identity", null); requirement.addDirective("filter", String.format("(%s=%s)", "osgi.identity", "*")); Map<Requirement, Collection<Capability>> result = repo .findProviders(Collections.singleton(requirement)); for (Capability c : result.values().iterator().next()) { String type = (String) c.getAttributes().get("type"); if (type != null && type.equals("osgi.bundle")) { ComponentDescription component = new ComponentDescription(); component.componentId = (String) c.getAttributes().get("osgi.identity"); component.version = c.getAttributes().get("version").toString(); component.nodes = getComponentNodes(component.componentId, component.version); components.add(component); } } } catch (Exception e) { } } return components; } private List<String> getComponentNodes(String componentId, String version) { List<String> nodes = new ArrayList<String>(); PlatformManager platform = platformTracker.getService(); for (ComponentInfo c : platform.getComponents(componentId, version)) { nodes.add(c.getNodeId()); } return nodes; } private class ComponentDescription { String componentId; String version; List<String> nodes; } }