How do I change java logging console output from std err to std out

Question

I'm using the standard logger from java.util.logging and by default the console output is directed to the error stream (i.e. same as System.err.println). How do I change the console output to the output stream (i.e. same as System.out.println)

Answer 1

Have a look at the docs and source for ConsoleHandler - I'm sure you could easily write a version which just uses System.err instead of System.out. (It's a shame that ConsoleHandler doesn't allow this to be configured, to be honest.)

Then it's just a case of configuring the logging system to use your new StdoutHandler (or whatever you call it) in the normal way.

Answer 2

If you use Java logging, you can change the default handler:

For example, for files: Handler fh = new FileHandler(FILENAME); Logger.getLogger(LOGGER_NAME).addHandler(fh);

If you want to output to a stream you can use StreamHandler, I think you can configure it with any output stream that you woud like, including the system stream.

Answer 3

I figured out one way. First remove the default console handler:

setUseParentHandlers(false);

Then subclass ConsoleHandler and in the constructor:

setOutputStream(System.out);

Answer 4

If you set setUseParentHandlers(false); only THAT class has it set. Other classes in the app will still pass it thru to stderr.

Answer 5

Simply extend StreamHandler & in the constructor call Super(System.out,). This will avoid closing System.err - Thanks

Answer 6

Handler consoleHandler = new Handler(){

            @Override
            public void publish(LogRecord record)
            {
                if (getFormatter() == null)
                {
                    setFormatter(new SimpleFormatter());
                }

                try {
                    String message = getFormatter().format(record);
                    if (record.getLevel().intValue() >= Level.WARNING.intValue())
                    {
                        System.err.write(message.getBytes());                       
                    }
                    else
                    {
                        System.out.write(message.getBytes());
                    }
                } catch (Exception exception) {
                    reportError(null, exception, ErrorManager.FORMAT_FAILURE);
                    return;
                }

            }

            @Override
            public void close() throws SecurityException {}
            @Override
            public void flush(){}
        };