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.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.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.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 MySqlTableComponent implements DatabaseComponent, MeasurementFacet { private String tableName; private MySqlDatabaseComponent parent; private String databaseName; private Log log = LogFactory.getLog(this.getClass()); @Override public Connection getConnection() { return parent.getConnection(); } @Override public void removeConnection() { parent.removeConnection(); } @Override public void start(ResourceContext rc) throws InvalidPluginConfigurationException, Exception { tableName = rc.getResourceKey(); parent = (MySqlDatabaseComponent) rc.getParentResourceComponent(); databaseName = parent.getName(); } @Override public void stop() { } @Override public AvailabilityType getAvailability() { AvailabilityType result = AvailabilityType.DOWN; Connection conn = parent.getConnection(); if (conn != null) { Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery("show tables from " + databaseName + " like '" + tableName + "'"); if (rs.first()) { result = AvailabilityType.UP; } } catch (SQLException se) { // ignore as unablailable if we can't execute the query } finally { DatabaseQueryUtility.close(stmt, rs); } } return result; } @Override public void getValues(MeasurementReport mr, Set<MeasurementScheduleRequest> set) throws Exception { Connection conn = parent.getConnection(); if (conn != null) { Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery("show table status from " + databaseName + " like '" + tableName + "'"); if (rs.next()) { for (MeasurementScheduleRequest request : set) { String value = rs.getString(request.getName()); if (value == null) { value = "0"; } switch (request.getDataType()) { case MEASUREMENT: { mr.addData(new MeasurementDataNumeric(request, Double.valueOf(value))); break; } case TRAIT: { mr.addData(new MeasurementDataTrait(request, value)); break; } default: { break; } } } } } catch (Exception se) { if (log.isInfoEnabled()) { log.info("Unable to measure table statistics", se); } } finally { DatabaseQueryUtility.close(stmt, rs); } } } }