Changing logging format in java with new class

Question

I would like to change my log format.

What I have:

Jul 23, 2019 10:17:02 PM myclass log INFO: message

What I want:

Jul 23, 2019 10:17:02 INFO: message

how can I do that, can you help me?

public class AIVLogger {

    private static Logger logger = Logger.getLogger(AIVLogger.class.getName());
    private static FileHandler fh = null;
    private static String logFolder = System.getProperty("user.dir") + File.separator + "Configuration_Data" + File.separator + "log";
    private static String logFile = logFolder + File.separator + "logger";

    public static void initialize() {

        try {
            new File(logFolder).mkdirs();
            fh = new FileHandler(logFile + "_" + GenericFuncs.getTimeNowFileName() + ".txt", false);
        } catch (SecurityException e) {
            AIVLogger.log(e.getMessage());
        } catch (IOException e) {
            AIVLogger.log(e.getMessage());
        }
        fh.setFormatter(new SimpleFormatter());
        logger.addHandler(fh);
        logger.setLevel(Level.ALL);
    }

    public static Logger getInstance() {
        return logger;
    }

    public static void log(String logMessage) {
        //logger.log(logger.getLevel(), logMessage);
        Level x = logger.getLevel();
        logger.log(x, logMessage);
    }

}

This is the class that I'm trying to change.

Have you created the class `FileHandler` or is it from a library? — deHaar, Jul 23 '19 at 10:04
It´s from a library. I would like to @override the 'toString' method. — Afonso Marques, Jul 23 '19 at 10:12
You will have to inherit from that class if it is from a library and you want to override `toString()`. — deHaar, Jul 23 '19 at 10:14
Please add some example (Java code, not log output) where you use the class `FileHandler`. Is it `java.util.logging.FileHandler`? — deHaar, Jul 23 '19 at 10:24
I think you can find a way [here in the JavaDocs of `SimpleFormat`](https://docs.oracle.com/javase/7/docs/api/java/util/logging/SimpleFormatter.html). — deHaar, Jul 23 '19 at 10:51
Possible duplicate of [How do i modify a log format with Simple Formatter?](https://stackoverflow.com/questions/49186029/how-do-i-modify-a-log-format-with-simple-formatter) — jmehrens, Jul 25 '19 at 20:55

score 0 · Answer 1 · answered Jul 23 '19 at 09:40

0

This entirely depends on the logging framework you are using. For example:

If you are just using System.out.println() it is as simple as changing the string you print
If you are using Logback, you can define custom layout classes that extend LayoutBase<ILoggingEvent>, and set it in your layouts xml file.

In general, look up the documentation for the logging framework you are using, or provide this information in the question.

answered Jul 23 '19 at 09:40

cameron1024

9,083
2
16
36

In fact I want to change this SimpleFormatter. `fh.setFormatter(new SimpleFormatter());` – Afonso Marques Jul 23 '19 at 09:45
@AfonsoMarques What type does `fh` have? – deHaar Jul 23 '19 at 09:50
@deHaar It isFileHandler fh – Afonso Marques Jul 23 '19 at 10:00

score 0 · Accepted Answer · answered Jul 24 '19 at 09:10

The best way to solve the problem is create a class that extend Formatter and create your own format. This worked for me:

private static final DateFormat df = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");

public String format(LogRecord record) {
    StringBuilder builder = new StringBuilder(1000);
    builder.append(df.format(new Date(record.getMillis()))).append(" - ");
    builder.append("[").append(record.getLevel()).append("] : ");
    builder.append(formatMessage(record));
    builder.append("\n");
    return builder.toString();
}

public String getHead(Handler h) {
    return super.getHead(h);
}

public String getTail(Handler h) {
    return super.getTail(h);
}

Changing logging format in java with new class

2 Answers2