Logging with Log4j in Selenium Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Logger instance for the class.

Selenium Java

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

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

AgetLogger

BcreateLogger

CnewLogger

DinitLogger

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent method like createLogger.

Trying to instantiate Logger with new keyword.

The Logger.getLogger(ClassName.class) method creates a Logger instance for the given class.

2fill in blank

medium

Complete the code to log an info message using Log4j.

Selenium Java

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

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

Ainfo

Bdebug

Cwarn

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using debug instead of info for general messages.

Using error or warn which are for problems.

The info method logs informational messages that highlight the progress of the application.

3fill in blank

hard

Fix the error in the code to log an error message with an exception.

Selenium Java

try {
    int result = 10 / 0;
} catch (ArithmeticException e) {
    logger.[1]("Division by zero error", e);
}

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

Awarn

Bdebug

Cinfo

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using warn instead of error for exceptions.

Logging exceptions with info or debug levels.

The error method is used to log error messages along with exceptions.

4fill in blank

hard

Fill both blanks to configure Log4j to log messages at debug level and above.

Selenium Java

BasicConfigurator.[1]();
Logger.getRootLogger().setLevel(Level.[2]);

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

Aconfigure

Binitialize

Cstart

Dsetup

Attempts:

3 left

💡 Hint

Common Mistakes

Using initialize instead of configure for setup.

Using lowercase level names.

BasicConfigurator.configure() sets up a basic configuration for Log4j.

Level.DEBUG sets the logging level to debug and above.

5fill in blank

hard

Fill all three blanks to create a logger, log a warning, and set the logger level to WARN.

Selenium Java

Logger [1] = Logger.[2](MyTest.class);
[1].warn("This is a warning message.");
[1].setLevel(Level.[3]);

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

Alogger

BgetLogger

CWARN

DcreateLogger

Attempts:

3 left

💡 Hint

Common Mistakes

Using createLogger which does not exist.

Setting level to lowercase 'warn' instead of uppercase 'WARN'.

First, create a Logger instance named logger using Logger.getLogger().

Then log a warning with warn().

Finally, set the level to Level.WARN to log warnings and above.

Practice

1. What is the main purpose of using Log4j in Selenium Java tests?

easy

A. To create graphical user interfaces for tests

B. To speed up the execution of Selenium tests

C. To record messages about test execution for debugging and analysis

D. To manage database connections during tests

Solution

1. Step 1: Understand Log4j's role

   Log4j is a logging tool used to record messages during program execution.

2. Step 2: Relate to Selenium tests

   In Selenium tests, logging helps track what happens and find issues.

3. Final Answer:

   To record messages about test execution for debugging and analysis -> Option C

4. Quick Check:

   Logging = record messages [OK]

Hint: Log4j records messages, not speeds or creates UI [OK]

Common Mistakes:

• Thinking Log4j speeds up tests
• Confusing logging with UI creation
• Assuming Log4j manages databases

2. Which of the following is the correct way to create a Logger instance using Log4j in Java?

easy

A. Logger logger = Logger.getLogger("MyLogger");

B. Logger logger = new Logger();

C. Logger logger = Logger.createLogger();

D. Logger logger = Logger.initLogger("MyLogger");

Solution

1. Step 1: Recall Log4j Logger creation syntax

   Log4j uses Logger.getLogger(String name) to create or get a logger.

2. Step 2: Check options

   Only Logger logger = Logger.getLogger("MyLogger"); uses the correct method Logger.getLogger("MyLogger").

3. Final Answer:

   Logger logger = Logger.getLogger("MyLogger"); -> Option A

4. Quick Check:

   Use getLogger() to create Logger [OK]

Hint: Use Logger.getLogger("name") to create logger [OK]

Common Mistakes:

• Trying to instantiate Logger with new
• Using non-existent methods like createLogger or initLogger
• Missing the logger name string

3. Given the following Log4j code snippet, what will be the output if the log level is set to WARN?

Logger logger = Logger.getLogger("TestLogger");
logger.info("Info message");
logger.warn("Warning message");
logger.error("Error message");

medium

A. Info message, Warning message, Error message

B. Warning message, Error message

C. Error message only

D. No output

Solution

1. Step 1: Understand log level filtering

   Log4j outputs messages at or above the set level. WARN level shows WARN and ERROR but not INFO.

2. Step 2: Apply to given messages

   INFO is below WARN, so skipped. WARN and ERROR messages are shown.

3. Final Answer:

   Warning message, Error message -> Option B

4. Quick Check:

   Log level WARN shows WARN and ERROR [OK]

Hint: Log4j shows messages at or above set level [OK]

Common Mistakes:

• Assuming all messages print regardless of level
• Thinking INFO is shown at WARN level
• Confusing ERROR with higher or lower level

4. You wrote this Log4j code but no logs appear when running your Selenium tests:

Logger logger = Logger.getLogger("MyTestLogger");
logger.debug("Debug message");

What is the most likely reason?

medium

A. The log level is set higher than DEBUG, so debug messages are ignored

B. The logger was not created correctly

C. You must call logger.start() before logging

D. Log4j does not support DEBUG level

Solution

1. Step 1: Check logger creation

   The logger creation syntax is correct, so this is not the issue.

2. Step 2: Understand log level filtering

   If the log level is set above DEBUG (like INFO or WARN), debug messages won't show.

3. Final Answer:

   The log level is set higher than DEBUG, so debug messages are ignored -> Option A

4. Quick Check:

   Higher log level hides lower level messages [OK]

Hint: Check log level; DEBUG hidden if level is INFO or higher [OK]

Common Mistakes:

• Thinking logger needs start() method
• Assuming DEBUG is unsupported
• Believing logger creation failed silently

5. You want to log messages in your Selenium Java tests using Log4j so that only ERROR and FATAL messages appear in the console, but INFO and WARN messages are saved to a file. Which Log4j feature should you use to achieve this?

hard

A. Use only one appender and filter messages in code before logging

B. Set the global log level to ERROR and log INFO messages manually to file

C. Log4j cannot separate messages by level to different outputs

D. Use two appenders with different thresholds and configure them in log4j.properties

Solution

1. Step 1: Understand Log4j appenders

   Appenders send log messages to different outputs like console or files.

2. Step 2: Use multiple appenders with thresholds

   You can configure one appender for console with ERROR level, and another for file with INFO or WARN level.

3. Step 3: Configure in log4j.properties

   This setup is done in the configuration file, not by manual code filtering.

4. Final Answer:

   Use two appenders with different thresholds and configure them in log4j.properties -> Option D

5. Quick Check:

   Multiple appenders + thresholds = selective logging [OK]

Hint: Use multiple appenders with level filters in config file [OK]

Common Mistakes:

• Trying to filter messages manually in code
• Setting global level only without appenders
• Thinking Log4j can't split outputs by level