Redirecting FileOutputStream to console - Java

Question

I'd like to rewrite and simply my code to cut down on the number of methods in a class that do exactly the same thing but either write to a file, or to a console so I can do things like:

PrintFlightSchedule(String aFileName); // prints to a file
PrintFlightSchedule(); // writes to console.

I've tried creating the following test method just to demonstrate what I'my trying to achieve, by defining an abstract OutputStream, then instantiating it as either a PrintStream, or console (via System.out):

public static void testOutputStream(String fileNm, String msg) {
    OutputStream os;
    if (fileNm.equals("") ) { // No file name provided, write to console
        os = System.out;
    }
    // File name provided, write to this file name
    else {
        try {
            os = new FileOutputStream(fileNm);
        }
        catch (FileNotFoundException fe) {
            System.out.println("File not found " + fe.toString());
        }
    }
    // Use the output stream here - ideally println method?
    // os.println or write(6);
}

This is admittedly half-assed, but it gives you an idea what I'd like to achieve.

Is there a way in Java to define the output method (file or console) at run-time, so I can use the same methods to do either, at runtime? I guess a simple way would be to redirect the FileOutputStream to the console - is that possible?

Answer 1

Basically, you need to create a method that simply takes a OutputStream and writes all the details to it...

Then you create some helper methods that simply call it with the appropriate stream...

public void printFlightSchedule(OutputStream os) throws IOException {
    // Write...
}

public void printFlightSchedule(File file) throws IOException {
    FileOutputStream fis = null;
    try {
        fis = new FileOutputStream(file);
        printFlightSchedule(fis);
    } finally {
        try {

        } catch (Exception e) {
        }
    }
}

public void printFlightSchedule() throws IOException {
    printFlightSchedule(System.out);
}

You may also want to take look at the Code Conventions for the Java Language...It will make it easier for people to read and understand your code ;)