Package-level log configuration in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the log level for a package in application.properties.

Spring Boot

logging.level.[1]=DEBUG

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

Aspring.datasource

Broot

Cserver.port

Dcom.example.myapp

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'root' instead of the package name for package-level logging.

Confusing server or datasource properties with logging configuration.

To configure logging for a specific package, use the package name as the key after logging.level. in application.properties.

2fill in blank

medium

Complete the code to set the log level to WARN for the package 'org.springframework.web'.

Spring Boot

logging.level.[1]=WARN

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

Aorg.springframework.boot

Borg.springframework.web

Corg.hibernate

Dorg.apache.catalina

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing unrelated packages like org.hibernate or org.apache.catalina.

Using the boot package instead of the web package.

To configure logging for the web package of Spring Framework, use org.springframework.web as the package name.

3fill in blank

hard

Fix the error in the YAML configuration to set DEBUG level for 'com.example.service'.

Spring Boot

logging:
  level:
    [1]: DEBUG

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

Acom.example.service

Bcom.example.controller

Ccom.example.repository

Dcom.example

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong package name that does not match the service layer.

Incorrect indentation or key names in YAML.

In YAML, the package name is used as the key under logging.level to set the log level for that package.

4fill in blank

hard

Fill both blanks to configure package-level logging in application.properties for 'com.app' at INFO and 'com.app.db' at ERROR.

Spring Boot

logging.level.[1]=INFO
logging.level.[2]=ERROR

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

Acom.app

Bcom.app.db

Ccom.application

Dcom.database

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up package names or using incorrect names.

Setting the same level for both packages instead of different levels.

Use the exact package names to set different log levels for each package in application.properties.

5fill in blank

hard

Fill all three blanks to create a YAML snippet setting log levels: 'com.app' to DEBUG, 'com.app.api' to INFO, and 'com.app.api.v1' to WARN.

Spring Boot

logging:
  level:
    [1]: DEBUG
    [2]: INFO
    [3]: WARN

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

Acom.app

Bcom.app.api

Ccom.app.api.v1

Dcom.application.api

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect package names or wrong order.

Confusing the indentation or YAML syntax.

Each package name is used as a key under logging.level in YAML to set its log level.

Practice

1. What is the purpose of setting logging.level.<package>=<level> in Spring Boot's application.properties?

easy

A. To control the logging detail for a specific Java package

B. To define the database connection URL

C. To set the server port number

D. To configure the application's timezone

Solution

1. Step 1: Understand the configuration key

   The key logging.level.<package> is used to specify logging levels for Java packages in Spring Boot.

2. Step 2: Identify the purpose of this setting

   This setting controls how detailed the logs are for that package, helping to focus on important logs and reduce noise.

3. Final Answer:

   To control the logging detail for a specific Java package -> Option A

4. Quick Check:

   Package-level log control = A [OK]

Hint: Remember: logging.level.package sets log detail per package [OK]

Common Mistakes:

• Confusing logging level with server or database settings
• Trying to set logging level without specifying a package
• Using incorrect property keys like logging.package.level

2. Which of the following is the correct syntax to set the log level to DEBUG for the package com.example.service in application.properties?

easy

A. logging.level=com.example.service=DEBUG

B. log.level.com.example.service=DEBUG

C. logging.com.example.service.level=DEBUG

D. logging.level.com.example.service=DEBUG

Solution

1. Step 1: Recall the correct property format

   The correct format is logging.level.<package>=<level>, so the package name comes immediately after logging.level..

2. Step 2: Match the option to the format

   logging.level.com.example.service=DEBUG matches this format exactly: logging.level.com.example.service=DEBUG.

3. Final Answer:

   logging.level.com.example.service=DEBUG -> Option D

4. Quick Check:

   Correct syntax = B [OK]

Hint: Use logging.level.package=LEVEL exactly as shown [OK]

Common Mistakes:

• Adding extra '=' signs in the property
• Swapping order of package and level
• Using 'log.level' instead of 'logging.level'

3. Given the following application.properties settings:
logging.level.com.example=INFO
logging.level.com.example.service=DEBUG
What will be the log level for classes in com.example.service package?

medium

A. INFO

B. DEBUG

C. ERROR

D. WARN

Solution

1. Step 1: Understand package-level log hierarchy

   More specific package settings override broader ones. Here, com.example.service is more specific than com.example.

2. Step 2: Determine effective log level

   The com.example.service package is set to DEBUG, which overrides the INFO level set for com.example.

3. Final Answer:

   DEBUG -> Option B

4. Quick Check:

   Specific package level overrides general = C [OK]

Hint: More specific package log level overrides parent package [OK]

Common Mistakes:

• Assuming parent package level applies to all subpackages
• Ignoring more specific package settings
• Confusing INFO and DEBUG levels

4. You set logging.level.com.example=TRACE in application.properties but still see only INFO logs from com.example classes. What is the most likely cause?

medium

A. Logging is disabled globally

B. TRACE level is not supported in Spring Boot

C. Another configuration overrides the log level to INFO

D. The package name is misspelled in the properties file

Solution

1. Step 1: Verify if TRACE is supported

   TRACE is a valid log level in Spring Boot, so this is not the issue.

2. Step 2: Consider configuration overrides

   If logs show INFO instead of TRACE, likely another config (like environment variables or YAML) overrides the level to INFO.

3. Final Answer:

   Another configuration overrides the log level to INFO -> Option C

4. Quick Check:

   Config override causes unexpected log level = D [OK]

Hint: Check for conflicting configs if log level seems ignored [OK]

Common Mistakes:

• Assuming TRACE is unsupported
• Not checking for typos in package name
• Ignoring global logging settings

5. You want to reduce log noise by setting ERROR level for com.example.repository but keep DEBUG for com.example.service. Which application.properties configuration achieves this?

hard

A. logging.level.com.example.repository=ERROR
logging.level.com.example.service=DEBUG

B. logging.level.com.example=ERROR
logging.level.com.example.service=DEBUG

C. logging.level.com.example.repository=DEBUG
logging.level.com.example.service=ERROR

D. logging.level.com.example.repository=INFO
logging.level.com.example.service=DEBUG

Solution

1. Step 1: Set ERROR level specifically for repository package

   Use logging.level.com.example.repository=ERROR to reduce noise from repository logs.

2. Step 2: Set DEBUG level specifically for service package

   Use logging.level.com.example.service=DEBUG to keep detailed logs for service package.

3. Step 3: Combine both settings correctly

   logging.level.com.example.repository=ERROR logging.level.com.example.service=DEBUG correctly sets both packages with their respective levels in application.properties.

4. Final Answer:

   logging.level.com.example.repository=ERROR logging.level.com.example.service=DEBUG -> Option A

5. Quick Check:

   Separate package levels set correctly = A [OK]

Hint: Set each package level separately for precise control [OK]

Common Mistakes:

• Setting parent package level instead of specific packages
• Swapping log levels between packages
• Using incorrect property keys or syntax