LogContextMissingStrategy with customizable logging level

Currently LogErrorContextMissingStrategy uses commons-logging and always logs error:

https://github.com/aws/aws-xray-sdk-java/blob/01d52aee854baae36ad9224598ffa709290d7afa/aws-xray-recorder-sdk-core/src/main/java/com/amazonaws/xray/strategy/LogErrorContextMissingStrategy.java#L18

My suggestion:

1. Use slf4j-api instead, which is de facto standard for modern Java apps and also more performant
2. Add LogContextMissingStrategy which can be used to log to user-specified level. LogErrorContextMissingStrategy will just become a very thin subclass (for backwards compatbility) that uses Level.ERROR

What I use:

public static class LogContextMissingStrategy implements ContextMissingStrategy {
    private static final Logger logger = LoggerFactory.getLogger(LogContextMissingStrategy.class);
    private final Level level;
    private static final Map<Level, LoggingFunction> map;

    static {
        map = new HashMap<>();
        map.put(Level.TRACE, (logger, format, params) -> logger.trace(format, params));
        map.put(Level.DEBUG, (logger, format, params) -> logger.debug(format, params));
        map.put(Level.INFO, (logger, format, params) -> logger.info(format, params));
        map.put(Level.WARN, (logger, format, params) -> logger.warn(format, params));
        map.put(Level.ERROR, (logger, format, params) -> logger.error(format, params));
    }

    @FunctionalInterface
    private interface LoggingFunction {
        void log(Logger logger, String format, Object... params);
    }

    public LogContextMissingStrategy(Level level) {
        this.level = level;
    }

    /**
     * Logs {@code message} on the specified level.
     * @param message the message to log
     * @param exceptionClass the type of exception suppressed in favor of logging {@code message}
     */
    @Override
    public void contextMissing(String message, Class<? extends RuntimeException> exceptionClass) {
        map.get(level).log(logger, "Suppressing AWS X-Ray context missing exception ({}): {}",
                exceptionClass.getSimpleName(), message);
    }

}

Inizia leggendo aws-xray-recorder-sdk-core/src/main/java/com/amazonaws/xray/strategy/LogErrorContextMissingStrategy.java e l’entry point ContextMissingStrategy. Confronta l’API LogContextMissingStrategy richiesta e il comportamento del livello di logging con l’implementazione esistente, quindi verifica che LogErrorContextMissingStrategy rimanga retrocompatibile e che la strategia configurabile registri al livello selezionato.