Can I use Scanner class in text file for getting information??

Question

this code is correct??

String note = "text.txt";
FileWriter file = new FileWriter(note);
Scanner sc = new Scanner(System.in);
System.out.println("Enter your name:");
String name = sc.next();
file.close();

How can I pass this file to the program as a command line argument???

Answer 1

Well, personally I'd never use FileWriter as it uses the system default encoding, which is a nasty thing to do most of the time. I prefer FileOutputStream + OutputStreamWriter. However, having said that...

What do you want to pass as the command line argument? The file name? That's easy:

public static void main(String[] args)
{
    // Insert error checking here (e.g. args.length == 0)
    String note = args[0]; // For the first argument
    // Rest of code here
}

If that's not what you mean, please edit your question to clarify it.

Judging by the title, you may be wanting to load from a file instead of from System.in. In that case, you just need to pass in a File object, or an InputStream (such as FileInputStream) or indeed a Readable (such as InputStreamReader). If you're going to pass in a File or InputStream, I'd strongly recommend that you pass in the character encoding name as well. (Quite why it takes it as a string instead of a Charset is beyond me, but the Java API is basically pretty bad when it comes to encodings.)