SLF4J and Logback basics in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a logger instance using SLF4J in a Spring Boot class.

Spring Boot

private static final Logger logger = LoggerFactory.[1](MyClass.class);

Drag options to blanks, or click blank then click option'

AcreateLogger

BnewLogger

CgetLogger

DbuildLogger

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like createLogger or newLogger which do not exist.

Use LoggerFactory.getLogger(ClassName.class) to create a logger instance in SLF4J.

2fill in blank

medium

Complete the code to log an informational message using SLF4J logger.

Spring Boot

logger.[1]("Application started successfully.");

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Awarn

Bdebug

Cerror

Dinfo

Attempts:

3 left

💡 Hint

Common Mistakes

Using debug or error for normal info messages.

Use info method to log informational messages.

3fill in blank

hard

Fix the error in the Logback configuration snippet to set the root logger level to DEBUG.

Spring Boot

<configuration>
  <root level="[1]">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

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Adebug

BDEBUG

CWarn

DINFO

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase like debug or mixed case like Warn.

Logback levels are case-sensitive and should be uppercase like DEBUG.

4fill in blank

hard

Fill both blanks to define a console appender in Logback XML configuration.

Spring Boot

<appender name="STDOUT" class="ch.qos.logback.core.[1]Appender">
  <encoder>
    <pattern>[2]</pattern>
  </encoder>
</appender>

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AConsole

B%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n

CFile

D%msg%n

Attempts:

3 left

💡 Hint

Common Mistakes

Using FileAppender for console output or wrong pattern strings.

The console appender class is ConsoleAppender and the pattern shows timestamp, thread, level, logger, and message.

5fill in blank

hard

Fill all three blanks to create a logger and log a warning message with a variable in a Spring Boot class.

Spring Boot

private static final Logger logger = LoggerFactory.[1](MyService.class);

public void checkStatus(String status) {
  logger.[2]("Status is: {}", [3]);
}

Drag options to blanks, or click blank then click option'

AgetLogger

Bwarn

Cstatus

Dinfo

Attempts:

3 left

💡 Hint

Common Mistakes

Using info instead of warn, or forgetting to pass the variable.

Create the logger with getLogger, log a warning with warn, and pass the variable status as argument.