Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2014 Red Hat, Inc. * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation version 2 of the License. * * 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */ package org.rhq.plugins.netservices; import static org.rhq.plugins.netservices.util.StringUtil.EMPTY_STRING; import static org.rhq.plugins.netservices.util.StringUtil.isBlank; import java.io.Closeable; import java.io.IOException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Socket; import java.net.UnknownHostException; import java.util.Set; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.rhq.core.domain.configuration.Configuration; import org.rhq.core.domain.measurement.AvailabilityType; import org.rhq.core.domain.measurement.MeasurementDataNumeric; import org.rhq.core.domain.measurement.MeasurementDataTrait; import org.rhq.core.domain.measurement.MeasurementReport; import org.rhq.core.domain.measurement.MeasurementScheduleRequest; import org.rhq.core.pluginapi.inventory.InvalidPluginConfigurationException; import org.rhq.core.pluginapi.inventory.ResourceComponent; import org.rhq.core.pluginapi.inventory.ResourceContext; import org.rhq.core.pluginapi.measurement.MeasurementFacet; /** * @author Thomas Segismont */ public class PortNetServiceComponent implements ResourceComponent, MeasurementFacet { public static final class ConfigKeys { private ConfigKeys() { // Defensive } public static final String ADDRESS = "address"; public static final String PORT = "port"; } private static final Log LOG = LogFactory.getLog(PortNetServiceComponent.class); private static final int CONNECTION_TIMEOUT = 2000; private PortNetServiceComponentConfiguration componentConfiguration; @Override public void start(ResourceContext resourceContext) throws InvalidPluginConfigurationException { componentConfiguration = createComponentConfiguration(resourceContext.getPluginConfiguration()); } static PortNetServiceComponentConfiguration createComponentConfiguration(Configuration pluginConfig) throws InvalidPluginConfigurationException { String addressString = pluginConfig.getSimpleValue(ConfigKeys.ADDRESS, EMPTY_STRING); if (isBlank(addressString)) { throw new InvalidPluginConfigurationException("Address is not defined"); } String portString = pluginConfig.getSimpleValue(ConfigKeys.PORT, EMPTY_STRING); if (isBlank(portString)) { throw new InvalidPluginConfigurationException("Port is not defined"); } int port; try { port = Integer.parseInt(portString); } catch (NumberFormatException e) { throw new InvalidPluginConfigurationException("Invalid port number: " + portString); } InetAddress address; try { address = InetAddress.getByName(addressString); } catch (UnknownHostException uhe) { throw new InvalidPluginConfigurationException(uhe); } return new PortNetServiceComponentConfiguration(address, port); } @Override public void stop() { componentConfiguration = null; } @Override public AvailabilityType getAvailability() { return portReachable() ? AvailabilityType.UP : AvailabilityType.DOWN; } @Override public void getValues(MeasurementReport report, Set<MeasurementScheduleRequest> metrics) throws Exception { for (MeasurementScheduleRequest request : metrics) { if (request.getName().equals("ipAddress")) { report.addData( new MeasurementDataTrait(request, componentConfiguration.getAddress().getHostAddress())); } else if (request.getName().equals("hostName")) { report.addData(new MeasurementDataTrait(request, componentConfiguration.getAddress().getCanonicalHostName())); } else if (request.getName().equals("connectTime")) { long start = System.currentTimeMillis(); if (portReachable()) { report.addData( new MeasurementDataNumeric(request, (double) (System.currentTimeMillis() - start))); } } } } private boolean portReachable() { Socket socket = null; try { socket = new Socket(); socket.connect( new InetSocketAddress(componentConfiguration.getAddress(), componentConfiguration.getPort()), CONNECTION_TIMEOUT); return true; } catch (Exception e) { if (LOG.isTraceEnabled()) { LOG.trace("Unable to reach remote port: " + componentConfiguration.toString(), e); } } finally { if (socket != null) { closeQuietly(socket); } } return false; } private void closeQuietly(Closeable closeable) { try { closeable.close(); } catch (IOException ignore) { } } }