Changing standard output in Java

There are a few things you can do. To answer your question, you would do something like

System.setOut(new FileOutputStream(myFile));

However, I would use a registration framework to write to a file. First, initialize your registrar somewhere:

FileHandler handler = new FileHandler("mylogfile.txt", true); // True to append to file, false to overwrite.
Logger logger = Logger.getLogger(getClass().getName());
logger.addHandler(handler);

Then you can use the method that you call every time you want to print something, for example:

public void output(String message, boolean toConsole, boolean toFile) {
    if (toConsole) {
        System.out.println(message);
    }
    if (toFile) {
        m_logger.info(message); // Your instance variable of Logger.
    }
}

, , . toConsole toFile , .