Java tutorial
/******************************************************************************* * This file is part of OpenNMS(R). * * Copyright (C) 2016 The OpenNMS Group, Inc. * OpenNMS(R) is Copyright (C) 1999-2016 The OpenNMS Group, Inc. * * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc. * * OpenNMS(R) 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. * * OpenNMS(R) 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 OpenNMS(R). If not, see: * http://www.gnu.org/licenses/ * * For more information contact: * OpenNMS(R) Licensing <license@opennms.org> * http://www.opennms.org/ * http://www.opennms.com/ *******************************************************************************/ package org.opennms.web.controller.trend; import java.io.File; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.DoubleSummaryStatistics; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.stream.Collectors; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.xml.bind.JAXB; import org.apache.commons.lang.StringUtils; import org.opennms.core.db.DataSourceFactory; import org.opennms.netmgt.config.trend.TrendConfiguration; import org.opennms.netmgt.config.trend.TrendDefinition; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.InitializingBean; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.AbstractController; public class TrendController extends AbstractController implements InitializingBean { private static final Logger LOG = LoggerFactory.getLogger(TrendController.class); private final File CONFIG_FILE = new File("etc/trend-configuration.xml"); @Override protected ModelAndView handleRequestInternal(final HttpServletRequest request, final HttpServletResponse response) throws Exception { final ModelAndView modelAndView = new ModelAndView("trend/trend"); final TrendDefinition trendDefinition = getConfiguration() .getTrendDefintionForName(request.getParameter("name")); if (trendDefinition != null) { final List<Double> valuesList = lookupData(trendDefinition.getQuery()); final String valuesString = StringUtils.join(valuesList, ','); final Map<String, String> replacements = variableReplacements(valuesList); trendDefinition.setTitle(replace(trendDefinition.getTitle(), replacements)); trendDefinition.setSubtitle(replace(trendDefinition.getSubtitle(), replacements)); trendDefinition.setDescription(replace(trendDefinition.getDescription(), replacements)); modelAndView.addObject("trendDefinition", trendDefinition); modelAndView.addObject("trendValues", valuesList); modelAndView.addObject("trendValuesString", valuesString); } else { LOG.warn("trend definition is null for name '{}'", request.getParameter("name")); } return modelAndView; } private Map<String, String> variableReplacements(final List<Double> values) { final Map<String, String> replacements = new HashMap<>(); final DoubleSummaryStatistics doubleSummaryStatistics = values.stream().mapToDouble(Double::doubleValue) .summaryStatistics(); replacements.put("${doubleMax}", String.format("%.2f", doubleSummaryStatistics.getMax())); replacements.put("${intMax}", String.format("%d", (int) doubleSummaryStatistics.getMax())); replacements.put("${doubleMin}", String.format("%.2f", doubleSummaryStatistics.getMin())); replacements.put("${intMin}", String.format("%d", (int) doubleSummaryStatistics.getMin())); replacements.put("${doubleAvg}", String.format("%.2f", doubleSummaryStatistics.getAverage())); replacements.put("${intAvg}", String.format("%d", (int) doubleSummaryStatistics.getAverage())); replacements.put("${doubleSum}", String.format("%.2f", doubleSummaryStatistics.getSum())); replacements.put("${intSum}", String.format("%d", (int) doubleSummaryStatistics.getSum())); for (int i = 0; i < values.size(); i++) { double current = values.get(i); replacements.put("${doubleValue[" + i + "]}", String.format("%.2f", current)); replacements.put("${intValue[" + i + "]}", String.format("%d", (int) current)); if (i > 0) { double previous = values.get(i - 1); double change = current - previous; replacements.put("${doubleValueChange[" + i + "]}", String.format("%+.2f", change)); replacements.put("${intValueChange[" + i + "]}", String.format("%+d", (int) change)); } else { replacements.put("${doubleValueChange[" + i + "]}", "NaN"); replacements.put("${intValueChange[" + i + "]}", "NaN"); } } if (values.size() > 0) { replacements.put("${doubleLastValueChange}", replacements.get("${doubleValueChange[" + (values.size() - 1) + "]}")); replacements.put("${intLastValueChange}", replacements.get("${intValueChange[" + (values.size() - 1) + "]}")); replacements.put("${doubleLastValue}", replacements.get("${doubleValue[" + (values.size() - 1) + "]}")); replacements.put("${intLastValue}", replacements.get("${intValue[" + (values.size() - 1) + "]}")); } else { replacements.put("${doubleLastValueChange}", "NaN"); replacements.put("${intLastValueChange}", "NaN"); replacements.put("${doubleLastValue}", "NaN"); replacements.put("${intLastValue}", "NaN"); } return replacements; } private String replace(String string, final Map<String, String> replacements) { for (final Map.Entry<String, String> replacement : replacements.entrySet()) { string = string.replace(replacement.getKey(), replacement.getValue()); } return string; } public TrendConfiguration getConfiguration() { return JAXB.unmarshal(CONFIG_FILE, TrendConfiguration.class); } public List<Double> lookupData(final String query) throws SQLException { final List<Double> dataSet = new ArrayList<Double>(); Connection connection = null; try { connection = DataSourceFactory.getInstance().getConnection(); final Statement statement = connection.createStatement(); final ResultSet resultSet = statement.executeQuery(query); while (resultSet.next()) { dataSet.add(resultSet.getDouble(1)); } resultSet.close(); statement.close(); } finally { if (connection != null) { connection.close(); } } return dataSet; } @Override public void afterPropertiesSet() { } }