How do I log an exception?

In this example you can see how we can log an exception when it occurs. In the code below we are trying to parse an invalid date which will give us a ParseException. To log the exception we call the Logger.log() method, passes the logger Level, add some user-friendly message and the Throwable object.

package org.kodejava.util.logging;

import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.Date;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.text.ParseException;

public class LoggingException {
    private static Logger logger =
            Logger.getLogger(LoggingException.class.getName());

    public static void main(String[] args) {
        DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
        df.setLenient(false);

        try {
            // Try to parse a wrong date.
            Date date = df.parse("12/30/1990");

            System.out.println("Date = " + date);
        } catch (ParseException e) {
            // Create a Level.SEVERE logging message
            if (logger.isLoggable(Level.SEVERE)) {
                logger.log(Level.SEVERE, "Error parsing date", e);
            }
        }
    }
}

The code above will produce the following log message.

Oct 07, 2021 8:21:44 PM org.kodejava.util.logging.LoggingException main
SEVERE: Error parsing date
java.text.ParseException: Unparseable date: "12/30/1990"
    at java.base/java.text.DateFormat.parse(DateFormat.java:399)
    at org.kodejava.util.logging.LoggingException.main(LoggingException.java:20)