How to implement logging in SpringBoot?

In SpringBoot, logging can be implemented using frameworks such as Logback, Log4J, and Log4J2. Typically, SpringBoot defaults to using Logback as the logging framework, so we can configure logging properties in the application.properties file to achieve logging.

Here is an example of configuring the log properties in the application.properties file:

# 设置日志级别为DEBUG
logging.level.root=DEBUG

# 输出日志到控制台
logging.pattern.console=%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n

# 输出日志到文件
logging.file=myapp.log
logging.pattern.file=%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n

In the configuration above, we have set the log level to DEBUG, meaning all logs at and above the DEBUG level will be recorded. Additionally, we have configured the log output format to be displayed in both the console and a file.

In addition to configuration files, we can also log messages in code using a Logger object, for example:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MyService {
    private static final Logger logger = LoggerFactory.getLogger(MyService.class);

    public void doSomething() {
        logger.debug("Doing something...");
        // do something
        logger.info("Something has been done.");
    }
}

With the configuration and code provided above, we can now implement logging in our SpringBoot application. Of course, the configuration and usage can be adjusted based on actual requirements and logging framework.