Log formatting configuration in Spring Boot - Mini Project: Build & Apply

Log Formatting Configuration in Spring Boot

📖 Scenario: You are building a Spring Boot application that logs messages. You want to make the logs easier to read by formatting them with a clear pattern.

🎯 Goal: Configure the Spring Boot application to use a custom log format pattern that shows the timestamp, log level, logger name, and message.

📋 What You'll Learn

Create a basic Spring Boot application properties file

Add a configuration variable for the log pattern

Apply the log pattern to the logging system

Verify the final log format configuration

💡 Why This Matters

🌍 Real World

Clear and consistent log formatting helps developers and system operators quickly understand application behavior and troubleshoot issues.

💼 Career

Knowing how to configure logging is essential for backend developers and DevOps engineers working with Spring Boot applications.

1

Create application.properties file

Create a file named application.properties in the src/main/resources folder with this exact content: logging.pattern.console= (leave it empty for now).

Spring Boot

# Create application.properties file with logging.pattern.console=
# Your code here

Need a hint?

This file controls Spring Boot settings including logging.

2

Add a log pattern variable

In the application.properties file, set logging.pattern.console to the pattern %d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n exactly.

Spring Boot

logging.pattern.console=
# Set the log pattern to show timestamp, level, logger, and message
# Your code here

Need a hint?

This pattern shows date/time, log level, logger name, and message in each log line.

3

Apply the log pattern in Spring Boot

Ensure your Spring Boot application uses the application.properties file with the logging.pattern.console property set to format console logs with the pattern %d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n.

Spring Boot

logging.pattern.console=%d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n
# Confirm Spring Boot uses this pattern for console logging
# Your code here

Need a hint?

Spring Boot automatically applies this property to console logs.

4

Complete and verify log formatting

Run your Spring Boot application and verify that console logs show the timestamp, log level, logger name, and message formatted as 2024-01-01 12:00:00 INFO com.example.MyClass - Application started.

Spring Boot

logging.pattern.console=%d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n
# Run the app and check the console log format
# Your code here

Need a hint?

Look at the console output when the app runs to confirm the format.