HowTos Log Management

Aus Salespoint

Define a Log

Description: As described in #Understand logging, a Log is the representation of the "log file", which only is a real file, if the specified OutputStream is the recommended FileOutputstream. For a global Log, you only have to define a GlobalOutputStream by calling the static method Log.setGlobalLogOutputStream(OutputStream newOS). For local logging, you have to initialize a new instance of Log, either by using the constructor, the static method Log.createLog(OutputStream newOS) or a LogCreator.

ToDo:

1. For the initialization find a place at the beginning of your application runtime to make sure, the LogOutputStream exists before any logging starts.
2. Due to the new FileOutputStream, remember to catch the thrown IOException.
3. Use the static method setGlobalOutputStream, which will initialize a new Log and a globally reachable OutputStream, enabling logging to it anywhere in your application.

Example Source Code:

1
    // within the main method, but may be anywhere before any logging starts
    public static void main(String[] args)
    {
        LogShop logShop = new LogShop();
        Shop.setTheShop(logShop);
 
        2
        // remember to catch the possible IOException of creating a new FileOutputStream
        try
        {
        3
        // the static method will initialize a new Log and set the FileOutputStream global
        // so it can be used anywhere in the application
            Log.setGlobalOutputStream(new FileOutputStream("machine.log", true));
        }
        catch(IOException ioException)
        {
            System.err.println("Unable to create log file."); 
        }
    }

Define a new LogEntry

Define a new LogEntryFilter

Define a new ProcessLogEntry

Implement the Interface Loggable

Log the opening and closing of a SalesPoint

Log the opening and closing of a log file

Understand logging