Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2008 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ package org.rhq.plugins.mysql; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Set; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.rhq.core.domain.measurement.AvailabilityType; import org.rhq.core.domain.measurement.MeasurementDataNumeric; 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.ResourceContext; import org.rhq.core.pluginapi.measurement.MeasurementFacet; import org.rhq.plugins.database.DatabaseComponent; import org.rhq.plugins.database.DatabaseQueryUtility; /** * * @author Steve Millidge (C2B2 Consulting Limited) */ public class MySqlUserComponent implements MeasurementFacet, DatabaseComponent { private String userName; private String host; private MySqlComponent parent; private Log log = LogFactory.getLog(this.getClass()); private ResourceContext context; @Override public Connection getConnection() { return parent.getConnection(); } @Override public void removeConnection() { parent.removeConnection(); } @Override public void start(ResourceContext rc) throws InvalidPluginConfigurationException, Exception { parent = (MySqlComponent) rc.getParentResourceComponent(); context = rc; userName = context.getPluginConfiguration().getSimple("userName").getStringValue(); host = context.getPluginConfiguration().getSimple("host").getStringValue(); } @Override public void stop() { } public void getValues(MeasurementReport mr, Set<MeasurementScheduleRequest> requests) throws Exception { Connection conn = getConnection(); ResultSet rs = null; Statement stmt = null; int activeConnections = 0; int totalConnections = 0; try { stmt = conn.createStatement(); rs = stmt.executeQuery( "select User,Host,State from information_schema.processlist where User='" + userName + "'"); while (rs.next()) { String hostVal = rs.getString(2); String state = rs.getString(3); if (hostVal.startsWith(host)) { if (state.length() > 1) { activeConnections++; } totalConnections++; } } } catch (SQLException sqle) { } finally { DatabaseQueryUtility.close(stmt, rs); } for (MeasurementScheduleRequest request : requests) { if (request.getName().equals("TotalConnections")) { mr.addData(new MeasurementDataNumeric(request, new Double((double) totalConnections))); } else if (request.getName().equals("ActiveConnections")) { mr.addData(new MeasurementDataNumeric(request, new Double((double) activeConnections))); } } } public AvailabilityType getAvailability() { AvailabilityType result = AvailabilityType.DOWN; Connection conn = getConnection(); ResultSet rs = null; Statement stmt = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery( "select User from mysql.user where User='" + userName + "' and Host='" + host + "'"); if (rs.first()) { result = AvailabilityType.UP; } } catch (SQLException sqle) { } finally { DatabaseQueryUtility.close(stmt, rs); } return result; } }