How can I append to log files in this simple Java Logging implementation?

Question

I got the following class to create and manage a Logger. Whenever across the code and program execution, calls to static getLogger() catch blocks are used to log.

public class Log {
    private static final Logger logger = Logger.getLogger("MyLog");  

    public static void iniciarLog() throws IOException {
        FileHandler fh;  

        try { 
//          fh = new FileHandler(System.getProperty("user.home")+System.getProperty("file.separator")+"TorrentDownloader.log");  
            fh = new FileHandler("%h/TorrentDownloader.log");  
            logger.addHandler(fh);
            SimpleFormatter formatter = new SimpleFormatter();  
            fh.setFormatter(formatter);  

            logger.info("Se inició el log"); 
        } catch (SecurityException | IOException e) {  
            logger.severe("Error al crear el log");
        } 
    }

    public static Logger getLogger() {
        return logger;
    }
}

However, how can I append to such logging file? All examples I've seen change a lot this implementation which I like as it's clear, brief and simple.

Rosenblatt

Answer 1

From the FileHandler constructor, you can specify a boolean to specify an append mode.

Do as following:

fh = new FileHandler("%h/TorrentDownloader.log", true);  

Kleper

Thanks, can you extend more about the count parameter? – Rosenblatt

Oops ... my bad, i misread the documentation, it's a default behaviour. I will update my answer. – Kleper

But, how would it change to use that constructor giving a different count? – Rosenblatt

It limit the number of files created with the limit parameter. Check the link in my answer for more information. – Kleper

Thanks. By the way, do you have experience with FX and data binding? I got this doubt: #23731404 – Rosenblatt

Answer 2

Use a different constructor

fh = new FileHandler("%h/TorrentDownloader.log", true);  

Jaquez

Answer 3

You can use this constructor:

FileHandler handler = new FileHandler(String pattern, boolean append);

and in your case, it's:

fh = new FileHandler("%h/TorrentDownloader.log", true);

This constructor creates a FileHandler with a file name pattern, and a boolean telling whether the FileHandler should append to any existing files or not.

And this article has a full explanation.

Nonperformance