Using simple class name in java logging formatter

Question

I have a SimpleFormatter for logging in my application with the string
"%1$tF %1$tT %4$-7s %2$s %5$s%6$s%n"

I would like to use the simple class name rather than the canonical name. Is there a format option I can use with the 2$ field? Or does this require writing a new Handler?

For example, rather than
2019-02-06 07:09:09 INFO simplex.tools.SIMPLEXScheduler main Start

I'd like to see
2019-02-06 07:09:09 INFO SIMPLEXScheduler main Start

HOw do you initialize your Logger with the full class name I suppose. Just put in the simple class name there. — Abacus
– Abacus, Commented Feb 6, 2019 at 17:59
I use Logger.getGlobal(). I call it from many different classes and it returns the right class name; I just don't want the full path to the class. — Hari Nair
– Hari Nair, Commented Feb 6, 2019 at 18:16
you could use the logp(Level level, String sourceClass, String sourceMethod, String msg) method to do your logging calls, passing in the simple class name and a perhaps empty method name, as this builds the LogRecords source entry But I'd rather recommend that you take your time to have a look at the different logging frameworks (skf4j, logback, log4j2 etc.), because they are way more flexible especially when it comes to formatting and controlling the output. — Abacus
– Abacus, Commented Feb 7, 2019 at 7:11

Guss · Accepted Answer · 2019-10-28 13:50:17Z

1

Is there a format option I can use with the 2$ field?

The SimpleFormatter only supports the functionality in the java.util.Formatter. Currently there is no way to format class name as simple class name.

Or does this require writing a new Handler?

One option is to write a new java.util.logging.Formatter. There are some hacks that you can do by just installing a java.util.logging.Filter to change the class name but you should avoid doing that. Use logp instead as suggested by P.J.Meisch

Disclaimer: I'm a content developer for com.sun.mail.util.logging package included with the JavaMail project.

If you have access to JavaMail you can use the com.sun.mail.util.logging.CompactFormatter which will only print the simple class name. The trade off is that it will print compact stack traces for exceptions. Arguments 1 through 6 are the same order as the SimpleFormatter so the same pattern can be used.

If you don't want to include JavaMail then you can use the com.sun.mail:logging-mailhandler artifact instead.

edited Oct 28, 2019 at 13:50

Guss

32.8k20 gold badges117 silver badges143 bronze badges

answered Feb 8, 2019 at 1:56

jmehrens

11.1k1 gold badge41 silver badges49 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Hari Nair Over a year ago

Thanks, I think writing a new Formatter would be the easiest solution.

Hari Nair · Accepted Answer · 2019-02-09 18:34:52Z

I wrote a custom Formatter as suggested by jmehrens. If I need something more complicated I may try moving to another framework like log4j but this does what I want for now. Thanks for the advice!

                Formatter formatter = new Formatter() {
                    @Override
                    public String format(LogRecord record) {
                        String source = "";
                        if (record.getSourceClassName() != null) {
                            try {
                                source = Class.forName(record.getSourceClassName()).getSimpleName();
                            } catch (ClassNotFoundException e) {
                                e.printStackTrace();
                            }
                            if (record.getSourceMethodName() != null) {
                                source += " " + record.getSourceMethodName();
                            }
                        } else {
                            source = record.getLoggerName();
                        }
                        String message = formatMessage(record);
                        String throwable = "";
                        if (record.getThrown() != null) {
                            StringWriter sw = new StringWriter();
                            PrintWriter pw = new PrintWriter(sw);
                            pw.println();
                            record.getThrown().printStackTrace(pw);
                            pw.close();
                            throwable = sw.toString();
                        }
                        return String.format(getLogFormat(), new Date(record.getMillis()), source,
                                record.getLoggerName(), record.getLevel(), message, throwable);
                    }

                };

You should catch LinkageError and RuntimeException thrown from Class.forName. Instead of logging the stacktrace you could just substitute the (record.getSourceClassName(). Otherwise if you run in to an issue with class loading in your current code you'll have the a blank class name.

Collectives™ on Stack Overflow

Using simple class name in java logging formatter

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related