There are several ways to check production logging in a Spring Boot application, some of which include:

• Using a logging framework such as Logback or Log4j: These frameworks can be configured to write log statements to a file or send them to a remote logging service such as Loggly or Elasticsearch.

• Using Spring Boot Actuator: Spring Boot Actuator provides a set of endpoints that can be used to monitor and manage a Spring Boot application. One of these endpoints, /actuator/logfile, can be used to view the contents of the application’s log file.

• Using a log management tool: Tools such as the Elastic Stack, Logstash, and Fluentd can be used to collect, process, and analyze log data from a Spring Boot application.

• You can also set up the logging level to ERROR,WARN,INFO,DEBUG,TRACE to check the logging in production.

• You may also want to look into using the Spring Cloud Sleuth for distributed tracing, which allows you to trace the flow of a request through a system of microservices.

LOG4J-java

  -logging API for java.

Advantage:

  Quick Debugging
  Problem Diagnosis ->  production 
  Easy Maintenance
  Cost and Time Savings

log level:

  import org.apache.log4j.*;  
  private static org.apache.log4j.Logger log = Logger.getLogger(LogClass.class);  
  ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF  
  fatal
  error
  warn
  info
  debug

search for error-> direction->up`

LOG4J:

logger.info
logger.fatal
logger.debug
logger.notify
logger.notifyall
logger.error
logger.equals
logger.tostring

POM.xml:

    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.12.1</version>
    </dependency>