Simple demonstration of Log4J 2's ThreadContext using Java

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
	<Appenders>
		<File name="File" fileName="log.txt" >
			<JSONLayout properties="true" compact="false" eventEol="true" />
		</File>
	</Appenders>
	<Loggers>
		<Root level="info">
			<AppenderRef ref="File" />
		</Root>
	</Loggers>
</Configuration>

MyAppMap.java

import java.util.UUID;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.ThreadContext;

public class MyAppStack {
	
	private static final Logger logger = LogManager.getLogger(MyAppStack.class);
	
	public void login(String username, UUID sessionID) {
		ThreadContext.push("sessionID", sessionID.toString());
		ThreadContext.push("username", username);
		logger.info("User logged in.")
	}
	
	public void logout() {
		logger.info("Logging out user.");
		ThreadContext.remove("username");
		ThreadContext.remove("sessionID");
		logger.info("User logged out.")
	}

	public static void main(String[] args) {
		UUID sessionID = java.util.UUID.randomUUID();
		String username = "admin";
		login(username, sessionID);
		logout();
	}
}

MyAppStack.java

import java.util.UUID;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.ThreadContext;

public class MyAppStack {
	
	private static final Logger logger = LogManager.getLogger(MyAppStack.class);
	
	public void login(String username, UUID sessionID) {
		ThreadContext.push(sessionID.toString());
		ThreadContext.push(username);
		logger.info("User logged in.")
	}
	
	public void logout() {
		logger.info("Logging out user.");
		ThreadContext.pop();
		ThreadContext.pop();
		logger.info("User logged out.")
	}

	public static void main(String[] args) {
		UUID sessionID = java.util.UUID.randomUUID();
		String username = "admin";
		login(username, sessionID);
		logout();
	}
}