use log4j

.classpath

@@ -5,5 +5,7 @@
 	<classpathentry kind="lib" path="/home/wn/workspace-java/MeasurementCollector/libraries/jmbus-3.0.1.jar"/>
 	<classpathentry kind="lib" path="/home/wn/workspace-java/MeasurementCollector/libraries/org.eclipse.paho.client.mqttv3-1.2.0.jar"/>
 	<classpathentry kind="lib" path="/home/wn/workspace-java/MeasurementCollector/libraries/quick-json-1.0.2.3.jar"/>
+	<classpathentry kind="lib" path="/home/wn/workspace-java/MeasurementCollector/libraries/log4j-core-2.9.1.jar"/>
+	<classpathentry kind="lib" path="/home/wn/workspace-java/MeasurementCollector/libraries/log4j-api-2.9.1.jar"/>
 	<classpathentry kind="output" path="bin"/>
 </classpath>

src/de/hottis/MeasurementCollector/ADataObject.java

@@ -3,7 +3,12 @@ package de.hottis.MeasurementCollector;
 import java.time.LocalDateTime;
 import java.util.Map;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 public abstract class ADataObject {
+	final protected Logger logger = LogManager.getRootLogger();
+
 	private LocalDateTime timestamp;
 	private String name;
 	private Map<String, Object> values;

src/de/hottis/MeasurementCollector/ADataParser.java

@@ -3,9 +3,13 @@ package de.hottis.MeasurementCollector;
 import java.time.LocalDateTime;
 import java.util.List;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.openmuc.jmbus.DataRecord;
 
 public abstract class ADataParser {
+	final protected Logger logger = LogManager.getRootLogger();
+
 	protected String name;
 	
 	public ADataParser(String name) {

src/de/hottis/MeasurementCollector/AMessageParser.java

@@ -3,7 +3,12 @@ package de.hottis.MeasurementCollector;
 import java.time.LocalDateTime;
 import java.util.Properties;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 public abstract class AMessageParser {
+	final protected Logger logger = LogManager.getRootLogger();
+
 	private String topic;
 	protected DataObjectQueue queue;
 	protected Properties config;

src/de/hottis/MeasurementCollector/MBusParser.java

@@ -48,7 +48,7 @@ public class MBusParser extends AMessageParser {
 					ADataParser dataParser = (ADataParser) constructor.newInstance(nameInDatabase);
 					
 					dataParsers.put(nameInMsg, dataParser);
-					System.out.println(dataParserClassName + " registered for " + nameInMsg + ", " + nameInDatabase);
+					logger.info(dataParserClassName + " registered for " + nameInMsg + ", " + nameInDatabase);
 				}
 			}
 		}
@@ -82,16 +82,16 @@ public class MBusParser extends AMessageParser {
 				List<ADataObject> measurementItems = dataParsers.get(name).parse(timestamp, dataRecords);
 
 				for (ADataObject ado : measurementItems) {
-					System.out.println(ado);
+					logger.debug(ado);
 				}
 
 				queue.add(measurementItems);
-				System.out.println("Queue size: " + queue.size());
+				logger.debug("Queue size: " + queue.size());
 			} else {
-				System.out.println("unknown name: " + name);
+				logger.warn("unknown name: " + name);
 			}
 		} catch (Exception e) {
-			System.out.println("Exception when handling mbus message: " + e);
+			logger.error("Exception when handling mbus message: " + e);
 		}
 
 	}

src/de/hottis/MeasurementCollector/MeasurementCollector.java

@@ -2,12 +2,17 @@ package de.hottis.MeasurementCollector;
 
 import java.util.Properties;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+
 public class MeasurementCollector {
 	static final String PROPS_FILENAME = "measurementCollector.props";
+	static final Logger logger = LogManager.getRootLogger();
 	
 	
 	public static void main(String[] args) throws Exception {
-		System.out.println("MeasurementCollector starting");
+		logger.info("MeasurementCollector starting");
 		
 		final Properties config = new Properties();
 		config.load(MeasurementCollector.class.getClassLoader().getResourceAsStream(PROPS_FILENAME));

src/de/hottis/MeasurementCollector/MqttReceiver.java

@@ -4,6 +4,8 @@ import java.time.LocalDateTime;
 import java.util.HashMap;
 import java.util.Properties;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.eclipse.paho.client.mqttv3.IMqttMessageListener;
 import org.eclipse.paho.client.mqttv3.MqttClient;
 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
@@ -13,6 +15,8 @@ import org.eclipse.paho.client.mqttv3.MqttMessage;
 
 
 public class MqttReceiver {
+	final protected Logger logger = LogManager.getRootLogger();
+
 	static final String MQTT_BROKER_PROP = "mqtt.broker";
 	static final String MQTT_CLIENTID_PROP = "mqtt.clientid";
 	static final String MQTT_USERNAME_PROP = "mqtt.username";
@@ -50,11 +54,7 @@ public class MqttReceiver {
 		try {
 			client = new MqttClient(broker, clientId);
 			client.connect(connOpts);
-			while (! client.isConnected()) {
-				System.out.print(".");
-			}
-			System.out.println();
-			System.out.println("Connected");
+			logger.info("Connected");
 		} catch (MqttException e) {
 			throw new MeasurementCollectorException("MqttReceiver.connect", e);
 		}
@@ -64,7 +64,7 @@ public class MqttReceiver {
 		try {
 			parsers.put(parser.getTopic(), parser);
 			client.subscribe(parser.getTopic(), listener);
-			System.out.println("Subscribed: " + parser.getTopic());
+			logger.info("Subscribed: " + parser.getTopic());
 		} catch (MqttException e) {
 			throw new MeasurementCollectorException("MqttReceiver.registerParser", e);
 		}