Add log4j logging example

MvnDemo/pom.xml

@@ -26,6 +26,12 @@
 			<version>5.8.1</version>
 			<scope>test</scope>
 		</dependency>
+
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-core</artifactId>
+			<version>2.24.2</version>
+		</dependency>
 	</dependencies>
 
 	<build>

MvnDemo/src/main/java/de/hs_mannheim/informatik/mvn/Main.java

@@ -1,14 +1,20 @@
 package de.hs_mannheim.informatik.mvn;
 
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
+
 public class Main {
+	private static final Logger LOG = LogManager.getLogger();
 
 	public static void main(String[] args) {
-		System.out.println("Hallo Maven!");
+		LOG.info("Hallo Maven!");
 		
 		System.out.println(new Main().add(3, 4));
 	}
 
 	public int add(int a, int b) {
+		LOG.info("a = {}, b = {}", a, b);
+		
 		return a + b;
 	}
 }

MvnDemo/src/main/resources/log4j2.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+	<Appenders>
+		<!-- Konsole Appender -->
+		<Console name="Console" target="SYSTEM_OUT">
+			<PatternLayout
+				pattern="%d{yyyy-MM-dd HH:mm:ss} [%t] %-5level %C{1} - %msg%n" />
+		</Console>
+	</Appenders>
+
+	<Loggers>
+		<!-- Root Logger -->
+		<Root level="info">
+			<AppenderRef ref="Console" />
+		</Root>
+	</Loggers>
+</Configuration>