3-a Logging with TinyLog

TinyLog Logging Tutorial for Beginners (Java)

In this tutorial, you will learn how to use TinyLog, a simple logging library for Java. We will show how to log messages, use different log levels, include variables in logs, and format them.

We will:

• Create a small Java project using Maven.

• Add TinyLog as a dependency.

• Write a few examples that show how to log messages.

2. Setting Up the Project

We will use Maven to manage our dependencies. If you already have a pom.xml file, open it and add TinyLog.

If not, create a new Maven project and include this in your pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>tinylog-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- TinyLog 2 dependency -->
        <dependency>
            <groupId>org.tinylog</groupId>
            <artifactId>tinylog-api</artifactId>
            <version>2.6.2</version>
        </dependency>
        <dependency>
            <groupId>org.tinylog</groupId>
            <artifactId>tinylog-impl</artifactId>
            <version>2.6.2</version>
        </dependency>
    </dependencies>
</project>

3. Your First Log Message

Now, let’s write a simple program.

Create a file called Main.java in the src/main/java/com/example folder.

package com.example;

import org.tinylog.Logger;

public class Main {
    public static void main(String[] args) {
        Logger.info("Hello from TinyLog!");

        // Using different log levels
        Logger.trace("Starting program...");
        Logger.debug("Debugging some details.");
        Logger.info("Everything is working fine.");
        Logger.warn("Something might be wrong.");
        Logger.error("Something went wrong!");

        // Using variables in log messages
        String name = "Alice";
        int score = 42;
        Logger.info("Player {} scored {} points!", name, score);
    }
}

When you run your program, you should see output like:

INFO: Hello from TinyLog!
TRACE: Starting program...
DEBUG: Debugging some details.
INFO: Everything is working fine.
WARN: Something might be wrong.
ERROR: Something went wrong!
INFO: Player Alice scored 42 points!

4. Configuring TinyLog

You can control TinyLog using a simple text file called tinylog.properties. Put it in your src/main/resources folder.

Example configuration:

# Set the minimum level of messages to show
level = info

# Choose where to write logs
writer = console
writer.format = {level}: {message}

You can change writer to write to a file instead:

writer = file
writer.file = logs/app.log
writer.format = {date} [{level}] {message}

Now your logs will be saved in logs/app.log.

If you want to log to multiple targets, you can define multiple writers:

# Console writer
writer1 = console
writer1.level = info
writer1.format = {date} [{level}] {message}

# File writer
writer2 = file
writer2.level = debug
writer2.file = logs/app.log
writer2.format = {date} [{level}] {thread}: {message}
writer2.append = true

Here:

• writer1 → logs to the console (standard output).

• writer2 → logs to a file (logs/app.log) and appends to it.

• Each writer can have its own level, format, etc.

Note that TinyLog automatically logs to all configured writers.

5. Understanding Formatters

TinyLog allows you to control how each log message looks using formatters. Formatters use placeholders wrapped in {} to represent information.

Here are the most common placeholders you can use in writer.format:

Placeholder	Description	Example
{date}	Current date and time	2025-10-15 14:32:01
{level}	Log level (INFO, WARN, etc.)	INFO
{thread}	Thread name	main
{tag}	Name of the custom logger/tag	MyApp
{class}	Class name	com.example.Main
{package}	Package name	com.example
{method}	Method name	main
{line}	Line number of the log call	15
{message}	The actual log message	Player Alice scored 42 points!
{exception}	Stack trace if an exception is logged	java.lang.Exception...

Example custom format:

writer.format = {date} [{thread}] {class}.{method}(): {level} - {message}

Output example:

2025-10-15 14:32:01 [main] com.example.Main.main(): INFO - Player Alice scored 42 points!

You can combine any placeholders you like to create your own log format.

6. Creating and Using Custom Loggers

In TinyLog, you can create custom loggers by using tags. Tags act as logger names.

import org.tinylog.Logger;

public class CustomLoggerExample {
    public static void main(String[] args) {
        // Default logger
        Logger.info("This is a default log message.");

        // Custom logger with tag "MyApp"
        Logger.tag("MyApp").info("This is a custom logger message.");

        // Another custom logger with tag "Database"
        Logger.tag("Database").warn("Database connection slow.");
    }
}

Output:

INFO: This is a default log message.
INFO [MyApp]: This is a custom logger message.
WARN [Database]: Database connection slow.

7. Study Sources for TinyLog

Here are useful resources to learn more about TinyLog:

• Official Documentation: https://tinylog.org/v2/

• Maven Central (dependency info): https://search.maven.org/artifact/org.tinylog/tinylog-api