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/wrappers/JDBCWrapper.java * * @author Sofiane Sarni * */ package gsn.wrappers; import gsn.Main; import gsn.storage.StorageManagerFactory; import org.slf4j.LoggerFactory; import org.slf4j.Logger; import org.apache.commons.io.FileUtils; import org.joda.time.format.DateTimeFormatter; import org.joda.time.format.ISODateTimeFormat; import gsn.beans.DataField; import gsn.beans.AddressBean; import gsn.beans.StreamElement; import gsn.beans.DataTypes; import gsn.storage.StorageManager; import gsn.storage.DataEnumerator; import java.sql.SQLException; import java.sql.Connection; import java.sql.ResultSet; import java.io.File; import java.io.IOException; import java.io.Serializable; import java.util.regex.Pattern; import java.util.regex.Matcher; /** * This JDBC wrapper enables one to reply the existing stream from a a table in a database. * parameters: table: table name, start-time: starting time to replay from */ public class JDBCWrapper extends AbstractWrapper { private static long DEFAULT_RATE = 1000; // 1 second in milliseconds private static long DEFAULT_BUFFER_SIZE = 100; private transient Logger logger = LoggerFactory.getLogger(this.getClass()); private DataField[] outputFormat; private int threadCounter = 0; private String table_name; private long start_time; private long rate = DEFAULT_RATE; private long buffer_size = DEFAULT_BUFFER_SIZE; private long latest_timed; private String checkPointDir; private String driver; private String username; private String password; private String databaseURL; String checkPointFile; StorageManager sm = null; String[] dataFieldNames; Byte[] dataFieldTypes; int dataFieldsLength; boolean useDefaultStorageManager = true; public String getWrapperName() { return "JDBCWrapper"; } public void dispose() { threadCounter--; } public DataField[] getOutputFormat() { return outputFormat; } public boolean initialize() { AddressBean addressBean = getActiveAddressBean(); table_name = addressBean.getPredicateValue("table-name"); databaseURL = addressBean.getPredicateValue("jdbc-url"); username = addressBean.getPredicateValue("username"); password = addressBean.getPredicateValue("password"); driver = addressBean.getPredicateValue("driver"); if ((databaseURL != null) && (username != null) && (password != null) && (driver != null)) { useDefaultStorageManager = false; sm = StorageManagerFactory.getInstance(driver, username, password, databaseURL, 8); logger.warn("Using specified storage manager: " + databaseURL); } else { sm = Main.getDefaultStorage(); logger.warn("Using default storage manager"); } if (table_name == null) { logger.warn("The > table-name < parameter is missing from the wrapper for VS " + this.getActiveAddressBean().getVirtualSensorName()); return false; } ////////////////// boolean usePreviousCheckPoint = true; String time = addressBean.getPredicateValue("start-time"); if (time == null) { logger.warn("The > start-time < parameter is missing from the wrapper for VS " + this.getActiveAddressBean().getVirtualSensorName()); return false; } if (time.equalsIgnoreCase("continue")) { latest_timed = getLatestProcessed(); usePreviousCheckPoint = false; logger.warn("Mode: continue => " + latest_timed); } else if (isISOFormat(time)) { try { DateTimeFormatter fmt = ISODateTimeFormat.dateTime(); start_time = fmt.parseDateTime(time).getMillis(); latest_timed = start_time; logger.warn("Mode: ISO => " + latest_timed); } catch (IllegalArgumentException e) { logger.warn("The > start-time < parameter is malformed (looks like ISO8601) for VS " + this.getActiveAddressBean().getVirtualSensorName()); return false; } } else if (isLong(time)) { try { latest_timed = Long.parseLong(time); logger.warn("Mode: epoch => " + latest_timed); } catch (NumberFormatException e) { logger.warn("The > start-time < parameter is malformed (looks like epoch) for VS " + this.getActiveAddressBean().getVirtualSensorName()); return false; } } else { logger.warn( "Incorrectly formatted > start-time < accepted values are: 'continue' (from latest element in destination table), iso-date (e.g. 2009-11-02T00:00:00.000+00:00), or epoch (e.g. 1257946505000)"); return false; } ////////////////// checkPointDir = addressBean.getPredicateValueWithDefault("check-point-directory", "jdbc-check-points"); checkPointFile = checkPointDir + "/" + table_name + "-" + this.getActiveAddressBean().getVirtualSensorName(); new File(checkPointDir).mkdirs(); if (usePreviousCheckPoint) { logger.warn("trying to read latest timestamp from chekpoint file ... " + checkPointFile); try { if (getLatestTimeStampFromCheckPoint() != 0) { latest_timed = getLatestTimeStampFromCheckPoint(); logger.warn("latest ts => " + latest_timed); } else logger.warn("wrong value for latest ts (" + getLatestTimeStampFromCheckPoint() + "), ignored"); } catch (IOException e) { logger.warn("Checkpoints couldn't be used due to IO exception."); logger.warn(e.getMessage(), e); } } ////////////////// Connection connection = null; try { logger.info("Initializing the structure of JDBCWrapper with : " + table_name); connection = sm.getConnection(); outputFormat = sm.tableToStructureByString(table_name, connection); } catch (SQLException e) { logger.error(e.getMessage(), e); return false; } finally { sm.close(connection); } dataFieldsLength = outputFormat.length; dataFieldNames = new String[dataFieldsLength]; dataFieldTypes = new Byte[dataFieldsLength]; for (int i = 0; i < outputFormat.length; i++) { dataFieldNames[i] = outputFormat[i].getName(); dataFieldTypes[i] = outputFormat[i].getDataTypeID(); } return true; } public long getLatestTimeStampFromCheckPoint() throws IOException { String val = FileUtils.readFileToString(new File(checkPointFile), "UTF-8"); long lastItem = 0; if (val != null && val.trim().length() > 0) lastItem = Long.parseLong(val.trim()); return lastItem; } public void run() { DataEnumerator data; try { Thread.sleep(2000); } catch (InterruptedException e) { logger.error(e.getMessage(), e); } Connection conn = null; ResultSet resultSet = null; while (isActive()) { try { conn = sm.getConnection(); StringBuilder query = new StringBuilder("select * from ").append(table_name) .append(" where timed > " + latest_timed + " limit 0," + buffer_size); resultSet = sm.executeQueryWithResultSet(query, conn); //logger.debug(query); while (resultSet.next()) { Serializable[] output = new Serializable[this.getOutputFormat().length]; long pk = resultSet.getLong(1); long timed = resultSet.getLong(2); //logger.warn("pk => "+ pk); //logger.warn("timed => "+ timed); for (int i = 0; i < dataFieldsLength; i++) { switch (dataFieldTypes[i]) { case DataTypes.VARCHAR: case DataTypes.CHAR: output[i] = resultSet.getString(i + 3); break; case DataTypes.INTEGER: output[i] = resultSet.getInt(i + 3); break; case DataTypes.TINYINT: output[i] = resultSet.getByte(i + 3); break; case DataTypes.SMALLINT: output[i] = resultSet.getShort(i + 3); break; case DataTypes.DOUBLE: output[i] = resultSet.getDouble(i + 3); break; case DataTypes.FLOAT: output[i] = resultSet.getFloat(i + 3); break; case DataTypes.BIGINT: output[i] = resultSet.getLong(i + 3); break; case DataTypes.BINARY: output[i] = resultSet.getBytes(i + 3); break; } //logger.warn(i+" (type: "+dataFieldTypes[i]+" ) => "+output[i]); } StreamElement se = new StreamElement(dataFieldNames, dataFieldTypes, output, timed); latest_timed = se.getTimeStamp(); //logger.warn(" Latest => " + latest_timed); this.postStreamElement(se); updateCheckPointFile(latest_timed); //logger.warn(se); } } catch (java.io.IOException e) { logger.error(e.getMessage(), e); } catch (SQLException e) { logger.error(e.getMessage(), e); } finally { sm.close(resultSet); sm.close(conn); } try { Thread.sleep(rate); } catch (InterruptedException e) { logger.error(e.getMessage(), e); } } } public void updateCheckPointFile(long timestamp) throws IOException { FileUtils.writeStringToFile(new File(checkPointFile), Long.toString(timestamp), "UTF-8"); } public long getLatestProcessed() { DataEnumerator data; long latest = -1; StringBuilder query = new StringBuilder("select max(timed) from ") .append(this.getActiveAddressBean().getVirtualSensorName()); try { data = sm.executeQuery(query, false); logger.warn("Running query " + query); while (data.hasMoreElements()) { StreamElement se = data.nextElement(); if (se.getData("max(timed)") != null) latest = (Long) se.getData("max(timed)"); logger.warn(" MAX ts = " + latest); logger.warn(se.toString()); } } catch (SQLException e) { logger.error(e.getMessage(), e); } catch (NullPointerException e) { logger.error(e.getMessage(), e); } return latest; } public boolean isISOFormat(String time) { //Example: 2009-11-02T00:00:00.000+00:00 String regexMask = "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}.\\d{3}[+-]\\d{2}:\\d{2}$"; Pattern pattern = Pattern.compile(regexMask); Matcher matcher = pattern.matcher(time); logger.debug("Testing... " + time + " <==> " + regexMask); if (matcher.find()) { logger.debug(">>>>> ISO FORMAT"); return true; } else return false; } public boolean isLong(String time) { String regexMask = "^\\d+$"; Pattern pattern = Pattern.compile(regexMask); Matcher matcher = pattern.matcher(time); logger.debug("Testing... " + time + " <==> " + regexMask); if (matcher.find()) { logger.debug(">>>>> LONG number"); return true; } else return false; } }