private static OutputChoice computeOutputChoice(String logFile, boolean cacheOutputStream) {
        if ("System.err".equalsIgnoreCase(logFile))
            if (cacheOutputStream)
                return new OutputChoice(OutputChoiceType.CACHED_SYS_ERR);
            else
                return new OutputChoice(OutputChoiceType.SYS_ERR);
        else if ("System.out".equalsIgnoreCase(logFile)) {
            if (cacheOutputStream)
                return new OutputChoice(OutputChoiceType.CACHED_SYS_OUT);
            else
                return new OutputChoice(OutputChoiceType.SYS_OUT);
        } else {
            try {
                FileOutputStream fos = new FileOutputStream(logFile);
                PrintStream printStream = new PrintStream(fos);
                return new OutputChoice(printStream);
            } catch (FileNotFoundException e) {
                Reporter.error("Could not open [" + logFile + "]. Defaulting to System.err", e);
                return new OutputChoice(OutputChoiceType.SYS_ERR);
            }
        }
    }
See https://jira.qos.ch/browse/SLF4J-499
@since 1.7.33 and 2.0.0-alpha6
slf4j-simple/src/main/java/org/slf4j/simple/SimpleLoggerConfiguration.java