Package com.azure.core.util.logging

Class ClientLogger

  • public class ClientLogger
extends Object
    This is a fluent logger helper class that wraps a pluggable Logger.

    This logger logs format-able messages that use {} as the placeholder. When a throwable is the last argument of the format varargs and the logger is enabled for verbose, the stack trace for the throwable is logged.

    A minimum logging level threshold is determined by the AZURE_LOG_LEVEL environment configuration. By default logging is disabled.

    Log level hierarchy

    1. Error
    2. Warning
    3. Info
    4. Verbose

    The logger is capable of producing json-formatted messages enriched with key value pairs. Context can be provided in the constructor and populated on every message or added per each log record.

    See Also:
    Configuration

    • Constructor Detail

      • ClientLogger

        public ClientLogger​(Class<?> clazz)
        Retrieves a logger for the passed class using the LoggerFactory.
        Parameters:
        clazz - Class creating the logger.

      • ClientLogger

        public ClientLogger​(String className)
        Retrieves a logger for the passed class name using the LoggerFactory.
        Parameters:
        className - Class name creating the logger.
        Throws:
        RuntimeException - when logging configuration is invalid depending on SLF4J implementation.

      • ClientLogger

        public ClientLogger​(Class<?> clazz,
                    Map<String,​Object> context)
        Retrieves a logger for the passed class using the LoggerFactory.
        Parameters:
        clazz - Class creating the logger.
        context - Context to be populated on every log record written with this logger. Objects are serialized with toString() method.

      • ClientLogger

        public ClientLogger​(String className,
                    Map<String,​Object> context)
        Retrieves a logger for the passed class name using the LoggerFactory with context that will be populated on all log records produced with this logger. 
         Map<String, Object> context = new HashMap<>();
 context.put("connectionId", "95a47cf");

 ClientLogger loggerWithContext = new ClientLogger(ClientLoggerJavaDocCodeSnippets.class, context);
 loggerWithContext.info("A formattable message. Hello, {}", name);
        Parameters:
        className - Class name creating the logger.
        context - Context to be populated on every log record written with this logger. Objects are serialized with toString() method.
        Throws:
        RuntimeException - when logging configuration is invalid depending on SLF4J implementation.

    • Method Detail

      • log

        public void log​(LogLevel logLevel,
                Supplier<String> message)
        Logs a format-able message that uses {} as the placeholder at the given logLevel.

        Code samples

        Logging with a specific log level

         logger.log(LogLevel.VERBOSE,
     () -> String.format("Param 1: %s, Param 2: %s, Param 3: %s", "param1", "param2", "param3"));
        Parameters:
        logLevel - Logging level for the log message.
        message - The format-able message to log.

      • log

        public void log​(LogLevel logLevel,
                Supplier<String> message,
                Throwable throwable)
        Logs a format-able message that uses {} as the placeholder at verbose log level.

        Code samples

        Logging with a specific log level and exception

         Throwable illegalArgumentException = new IllegalArgumentException("An invalid argument was encountered.");
 logger.log(LogLevel.VERBOSE,
     () -> String.format("Param 1: %s, Param 2: %s, Param 3: %s", "param1", "param2", "param3"),
     illegalArgumentException);
        Parameters:
        logLevel - Logging level for the log message.
        message - The format-able message to log.
        throwable - Throwable for the message. Throwable.

      • verbose

        public void verbose​(String message)
        Logs a message at verbose log level.

        Code samples

        Logging a message at verbose log level.

         logger.verbose("A log message");
        Parameters:
        message - The message to log.

      • verbose

        public void verbose​(String format,
                    Object... args)
        Logs a format-able message that uses {} as the placeholder at verbose log level.

        Code samples

        Logging a message at verbose log level.

         logger.verbose("A formattable message. Hello, {}", name);
        Parameters:
        format - The formattable message to log.
        args - Arguments for the message. If an exception is being logged, the last argument should be the Throwable.

      • info

        public void info​(String message)
        Logs a message at info log level.

        Code samples

        Logging a message at verbose log level.

         logger.info("A log message");
        Parameters:
        message - The message to log.

      • info

        public void info​(String format,
                 Object... args)
        Logs a format-able message that uses {} as the placeholder at informational log level.

        Code samples

        Logging a message at informational log level.

         logger.info("A formattable message. Hello, {}", name);
        Parameters:
        format - The format-able message to log
        args - Arguments for the message. If an exception is being logged, the last argument should be the Throwable.

      • warning

        public void warning​(String message)
        Logs a message at warning log level.

        Code samples

        Logging a message at warning log level.

         Throwable detailedException = new IllegalArgumentException("A exception with a detailed message");
 logger.warning(detailedException.getMessage());
        Parameters:
        message - The message to log.

      • warning

        public void warning​(String format,
                    Object... args)
        Logs a format-able message that uses {} as the placeholder at warning log level.

        Code samples

        Logging a message at warning log level.

         Throwable exception = new IllegalArgumentException("An invalid argument was encountered.");
 logger.warning("A formattable message. Hello, {}", name, exception);
        Parameters:
        format - The format-able message to log.
        args - Arguments for the message. If an exception is being logged, the last argument should be the Throwable.

      • error

        public void error​(String message)
        Logs a message at error log level.

        Code samples

        Logging a message at error log level.

         try {
     upload(resource);
 } catch (IOException ex) {
     logger.error(ex.getMessage());
 }
        Parameters:
        message - The message to log.

      • error

        public void error​(String format,
                  Object... args)
        Logs a format-able message that uses {} as the placeholder at error log level.

        Code samples

        Logging an error with stack trace.

         try {
     upload(resource);
 } catch (IOException ex) {
     logger.error("A formattable message. Hello, {}", name, ex);
 }
        Parameters:
        format - The format-able message to log.
        args - Arguments for the message. If an exception is being logged, the last argument should be the Throwable.

      • logThrowableAsWarning

        public <T extends Throwable> T logThrowableAsWarning​(T throwable)
        Logs the Throwable at the warning level and returns it to be thrown.

        This API covers the cases where a checked exception type needs to be thrown and logged. If a RuntimeException is being logged use logExceptionAsWarning(RuntimeException) instead.

        Type Parameters:
        T - Type of the Throwable being logged.
        Parameters:
        throwable - Throwable to be logged and returned.
        Returns:
        The passed Throwable.
        Throws:
        NullPointerException - If throwable is null.

      • logThrowableAsError

        public <T extends Throwable> T logThrowableAsError​(T throwable)
        Logs the Throwable at the error level and returns it to be thrown.

        This API covers the cases where a checked exception type needs to be thrown and logged. If a RuntimeException is being logged use logExceptionAsError(RuntimeException) instead.

        Type Parameters:
        T - Type of the Throwable being logged.
        Parameters:
        throwable - Throwable to be logged and returned.
        Returns:
        The passed Throwable.
        Throws:
        NullPointerException - If throwable is null.

      • canLogAtLevel

        public boolean canLogAtLevel​(LogLevel logLevel)
        Determines if the app or environment logger support logging at the given log level.
        Parameters:
        logLevel - Logging level for the log message.
        Returns:
        Flag indicating if the environment and logger are configured to support logging at the given log level.

      • atError

        public LoggingEventBuilder atError()
        Creates LoggingEventBuilder for error log level that can be used to enrich log with additional context.

        Code samples

        Logging with context at error level.

         logger.atVerbose()
     .addKeyValue("key", 1L)
     .log(() -> String.format("Param 1: %s, Param 2: %s, Param 3: %s", "param1", "param2", "param3"));
        Returns:
        instance of LoggingEventBuilder or no-op if error logging is disabled.

      • atWarning

        public LoggingEventBuilder atWarning()
        Creates LoggingEventBuilder for warning log level that can be used to enrich log with additional context.

        Code samples

        Logging with context at warning level.

         logger.atWarning()
     .addKeyValue("key", "value")
     .log("A formattable message. Hello, {}", name, exception);
        Returns:
        instance of LoggingEventBuilder or no-op if warn logging is disabled.

      • atInfo

        public LoggingEventBuilder atInfo()
        Creates LoggingEventBuilder for info log level that can be used to enrich log with additional context.

        Code samples

        Logging with context at info level.

         logger.atInfo()
     .addKeyValue("key", "value")
     .log("A formattable message. Hello, {}", name);
        Returns:
        instance of LoggingEventBuilder or no-op if info logging is disabled.

      • atVerbose

        public LoggingEventBuilder atVerbose()
        Creates LoggingEventBuilder for verbose log level that can be used to enrich log with additional context.

        Code samples

        Logging with context at verbose level.

         logger.atVerbose()
     .addKeyValue("key", 1L)
     .log(() -> String.format("Param 1: %s, Param 2: %s, Param 3: %s", "param1", "param2", "param3"));
        Returns:
        instance of LoggingEventBuilder or no-op if verbose logging is disabled.