Скачать или смотреть How to Configure Log4j to Output Only Error Logs to Console and Direct Other Logs to Files

Learn how to properly configure `Log4j2` to ensure that only error logs appear in the console while other logs are recorded in their respective files. Perfect for your Spring Boot applications!
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Disabling Console Logging in Log4j2

Introduction

When you're developing applications using the Spring Boot framework, robust logging is essential for monitoring and debugging. However, there may be scenarios where you want to keep your console logs clean by showing only error logs while directing other log levels to their respective files. If you're using Log4j2 for logging, making this adjustment can be a bit tricky, especially if you're new to configuring logging frameworks. Let's dive into how you can achieve this in your Log4j2 configuration.

The Issue at Hand

You might have encountered the challenge of wanting all logs to be stored in files but displayed only when an error occurs in the console. You've probably set your log levels and configured appenders, but somehow, adjusting these configurations still results in logs flooding the console.

Objectives

Your two primary goals are:

Ensure that only error logs are displayed on the console while all other logs are sent to their designated files.

Configure the system to direct logs with custom log levels to particular files once the first objective is achieved.

Solution Steps

To resolve the logging configuration issue, we need to make a few adjustments to your log4j2.xml file configuration. Below is the code snippet summarizing the necessary tweaks.

Updated Configuration

Here's the revised portion of the log4j2.xml configuration file:

[[See Video to Reveal this Text or Code Snippet]]

Key Changes Explained

Commenting Out Console Appender in Logger: By commenting out the line <AppenderRef ref="Console"/>, we prevent the logger from sending ALL logs (including INFO and DEBUG) to the console. Instead, we keep our focus on capturing only the error logs in the console via the root logger configuration.

Maintaining Loggers for File Output: Each appender reference (errorLog, infoLog, and serviceLog) is preserved within the specific logger, ensuring that relevant logs are still directed where they need to go—namely, their respective files based on log level.

Result

With these adjustments made to your configuration, you should now see:

Console: Displaying only error logs.

Files: Log entries for all levels (INFO, ERROR, and custom levels) being captured into their designated files.

Conclusion

By leveraging the Log4j2 configuration effectively, you can achieve a clean logging setup that only showcases error logs on the console while efficiently managing other logs in specific files. This configuration is particularly beneficial for maintaining readability in log outputs, especially in production environments where clarity is paramount. Feel free to tweak and test further based on your application's logging needs, and don't hesitate to reach out if you have any more questions!