Java tutorial
/** * Global Sensor Networks (GSN) Source Code * Copyright (c) 2006-2014, Ecole Polytechnique Federale de Lausanne (EPFL) * * This file is part of GSN. * * GSN 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, either version 3 of the License, or * (at your option) any later version. * * GSN 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 GSN. If not, see <http://www.gnu.org/licenses/>. * * File: src/gsn/http/datarequest/DownloadData.java * * @author Ali Salehi * @author Mehdi Riahi * @author Timotee Maret * @author Milos Stojanovic * */ package gsn.http.datarequest; import gsn.Main; import gsn.Mappings; import gsn.beans.StreamElement; import gsn.beans.VSensorConfig; import gsn.beans.DataField; import gsn.http.MultiDataDownload; import gsn.reports.beans.Stream; import gsn.storage.DataEnumerator; import java.io.OutputStream; import java.io.PrintWriter; import java.io.Serializable; import java.sql.Connection; import java.sql.SQLException; import java.util.LinkedList; import java.util.Map.Entry; import java.util.*; import org.apache.commons.collections.KeyValue; import org.apache.commons.lang.StringEscapeUtils; import org.slf4j.LoggerFactory; import org.slf4j.Logger; public class DownloadData extends AbstractDataRequest { private static transient Logger logger = LoggerFactory.getLogger(MultiDataDownload.class); private static final String PARAM_OUTPUT_TYPE = "outputtype"; private static final double MAX_SAMPLE_VALUES = 20000.0; public enum AllowedOutputType { csv, xml } private AllowedOutputType ot; private String csvDelimiter = ","; public DownloadData(Map<String, String[]> requestParameters) throws DataRequestException { super(requestParameters); } @Override public void process() throws DataRequestException { String outputType = QueriesBuilder.getParameter(requestParameters, PARAM_OUTPUT_TYPE); try { if (outputType == null) { throw new DataRequestException( "The following >" + PARAM_OUTPUT_TYPE + "< parameter is missing in your query."); } ot = AllowedOutputType.valueOf(outputType); if (ot == AllowedOutputType.csv) { // if (QueriesBuilder.getParameter(requestParameters, "delimiter") != null && !QueriesBuilder.getParameter(requestParameters, "delimiter").equals("")) { String reqdelimiter = QueriesBuilder.getParameter(requestParameters, "delimiter"); if (reqdelimiter.equals("tab")) { csvDelimiter = "\t"; } else if (reqdelimiter.equals("space")) { csvDelimiter = " "; } else if (reqdelimiter.equals("semicolon")) { csvDelimiter = ";"; } else if (reqdelimiter.equals("other") && QueriesBuilder.getParameter(requestParameters, "otherdelimiter") != null && !QueriesBuilder.getParameter(requestParameters, "otherdelimiter").equals("")) { csvDelimiter = QueriesBuilder.getParameter(requestParameters, "otherdelimiter"); } } } } catch (IllegalArgumentException e) { throw new DataRequestException("The >" + outputType + "< output type is not supported."); } } // public String outputResult() { // ByteArrayOutputStream baos = new ByteArrayOutputStream(); // outputResult(baos); // return baos.toString(); // } @Override public void outputResult(OutputStream os) { PrintWriter respond = new PrintWriter(os); Iterator<Entry<String, AbstractQuery>> iter = qbuilder.getSqlQueries().entrySet().iterator(); Entry<String, AbstractQuery> nextSqlQuery; DataEnumerator de = null; try { if (ot == AllowedOutputType.xml) { respond.println("<result>"); } while (iter.hasNext()) { nextSqlQuery = iter.next(); Connection connection = null; connection = Main.getStorage(nextSqlQuery.getKey()).getConnection(); de = Main.getStorage(nextSqlQuery.getKey()).streamedExecuteQuery(nextSqlQuery.getValue(), true, connection); //get units in hash map HashMap<String, String> fieldToUnitMap = new HashMap<String, String>(); VSensorConfig sensorConfig = Mappings.getVSensorConfig(nextSqlQuery.getKey()); DataField[] dataFieldArray = sensorConfig.getOutputStructure(); for (DataField df : dataFieldArray) { String unit = df.getUnit(); if (unit == null || unit.trim().length() == 0) unit = ""; fieldToUnitMap.put(df.getName().toLowerCase(), unit); } logger.debug("Data Enumerator: " + de); if (ot == AllowedOutputType.csv) { respond.println("# vsname:" + nextSqlQuery.getKey()); respond.println("# query:" + nextSqlQuery.getValue().getStandardQuery() + (nextSqlQuery.getValue().getLimitCriterion() == null ? "" : "(" + nextSqlQuery.getValue().getLimitCriterion() + ")")); for (KeyValue df : sensorConfig.getAddressing()) { respond.println( "# " + df.getKey().toString().toLowerCase() + ":" + df.getValue().toString()); } respond.println("# description:" + sensorConfig.getDescription()); } else if (ot == AllowedOutputType.xml) { respond.println("\t<!-- " + nextSqlQuery.getValue().getStandardQuery() + " -->"); for (KeyValue df : sensorConfig.getAddressing()) { respond.println( "\t<!-- " + StringEscapeUtils.escapeXml(df.getKey().toString().toLowerCase()) + ":" + StringEscapeUtils.escapeXml(df.getValue().toString()) + " -->"); } respond.println("\t<!-- description:" + StringEscapeUtils.escapeXml(sensorConfig.getDescription()) + " -->"); respond.println("\t<data vsname=\"" + nextSqlQuery.getKey() + "\">"); } FieldsCollection fc = qbuilder.getVsnamesAndStreams().get(nextSqlQuery.getKey()); boolean wantTimed = true; boolean firstLine = true; LinkedList<StreamElement> streamElements = new LinkedList<StreamElement>(); while (de.hasMoreElements()) { streamElements.add(de.nextElement()); } double valsPerVS = MAX_SAMPLE_VALUES / numberOfFieldsInRequest(); if (requestParameters.containsKey("sample") && "true".equalsIgnoreCase(requestParameters.get("sample")[0]) && streamElements.size() > valsPerVS) { //sampling int numOfVals = streamElements.size(); int left = (int) valsPerVS; int valsForAvg = (int) Math.ceil(numOfVals / valsPerVS); if (requestParameters.containsKey("sampling_percentage")) { try { String percentageString = requestParameters.get("sampling_percentage")[0]; int percentage = Integer.parseInt(percentageString); if (percentage > 0 && percentage <= 100 && numOfVals * percentage > 100) { left = numOfVals * percentage / 100; valsForAvg = (int) Math.ceil(numOfVals / left); } } catch (Exception e) { } } while (!streamElements.isEmpty()) { StreamElement se = null; if (numOfVals > left) { StreamElement[] seForSampling = new StreamElement[valsForAvg]; for (int i = 0; i < valsForAvg; i++) { seForSampling[i] = streamElements.removeLast(); } numOfVals -= valsForAvg; left--; se = sampleSkip(seForSampling); } else { se = streamElements.removeLast(); } if (ot == AllowedOutputType.csv) { formatCSVElement(respond, se, wantTimed, csvDelimiter, firstLine, fieldToUnitMap); } else if (ot == AllowedOutputType.xml) { formatXMLElement(respond, se, wantTimed, firstLine, fieldToUnitMap); } firstLine = false; } } else { while (!streamElements.isEmpty()) { if (ot == AllowedOutputType.csv) { formatCSVElement(respond, streamElements.removeLast(), wantTimed, csvDelimiter, firstLine, fieldToUnitMap); } else if (ot == AllowedOutputType.xml) { formatXMLElement(respond, streamElements.removeLast(), wantTimed, firstLine, fieldToUnitMap); } firstLine = false; } } if (ot == AllowedOutputType.xml) respond.println("\t</data>"); } if (ot == AllowedOutputType.xml) { respond.println("</result>"); } } catch (SQLException e) { logger.debug(e.getMessage()); } finally { respond.flush(); if (de != null) de.close(); } } private StreamElement sampleSkip(StreamElement[] seForSampling) { return seForSampling[seForSampling.length - 1]; } private int numberOfFieldsInRequest() { int toRet = 0; for (String vsname : requestParameters.get("vsname")) { String[] vsnameParts = vsname.split(":"); toRet += vsnameParts.length - 2; } return toRet; } private void formatCSVElement(PrintWriter respond, StreamElement se, boolean wantTimed, String cvsDelimiter, boolean firstLine, HashMap<String, String> fieldToUnitMap) { if (firstLine) { //names of vs fields (first line) respond.print("# "); if (wantTimed) respond.print("time"); for (int i = 0; i < se.getData().length; i++) { respond.print(cvsDelimiter); respond.print(se.getFieldNames()[i]); } respond.println(); //units (second line) respond.print("# "); if (wantTimed) respond.print(""); for (int i = 0; i < se.getData().length; i++) { respond.print(cvsDelimiter); respond.print(fieldToUnitMap.get(se.getFieldNames()[i].toLowerCase())); } respond.println(); } if (wantTimed) { respond.print(qbuilder.getSdf() == null ? se.getTimeStamp() : qbuilder.getSdf().format(new Date(se.getTimeStamp()))); } for (int i = 0; i < se.getData().length; i++) { respond.print(cvsDelimiter); respond.print(se.getData()[i]); } respond.println(); } private void formatXMLElement(PrintWriter respond, StreamElement se, boolean wantTimed, boolean firstLine, HashMap<String, String> fieldToUnitMap) { if (firstLine) { respond.println("\t\t<header>"); if (wantTimed) respond.println("\t\t\t<field unit=\"\">time</field>"); for (int i = 0; i < se.getData().length; i++) { respond.print("\t\t\t<field unit=\"" + fieldToUnitMap.get(se.getFieldNames()[i].toLowerCase())); respond.println("\">" + se.getFieldNames()[i] + "</field>"); } respond.println("\t\t</header>"); } respond.println("\t\t<tuple>"); if (wantTimed) respond.println("\t\t\t<field>" + (qbuilder.getSdf() == null ? se.getTimeStamp() : qbuilder.getSdf().format(new Date(se.getTimeStamp()))) + "</field>"); for (int i = 0; i < se.getData().length; i++) { respond.println("\t\t\t<field>" + se.getData()[i] + "</field>"); } respond.println("\t\t</tuple>"); } public AllowedOutputType getOt() { return ot; } }