Java 5.0 Tiger: A Developer's Notebook

Chapter 9. Formatting

Note

In this chapter:

• Creating a Formatter

• Writing Formatted Output

• Using the format( ) Convenience Method

• Using the printf( ) Convenience Method

Tiger has a rather innocent looking new class called java.util.Formatter. Despite its looks, though, this one class provides new functionality to all of Tiger’s output methods. To cut to the chase, all you former C programmers will finally get to compile code with printf( ) in it—there, now aren’t you smiling already?

Creating a Formatter

The simplest way to get started with the Formatter class is to create a new instance of it, and then do some work. You’ll see in later labs that this isn’t always the best way to go about business, but it’s as good a starting point as any.

How do I do that?

Formatter has several constructors, listed here:

	// No-args version -- not particularly useful
	public Formatter( );
	
	// Basically, the no-args version with a locale
	public Formatter(Locale l);
	
	// Creates a formatter with the supplied destination (sink)
	public Formatter(Appendable a);
	
	// Creates a formatter with the destination, using the supplied locale
	public Formatter(Appendable a, Locale l);
	
	// Creates a new formatter with the filename as the sink
	public Formatter(String fileName);
	
	// Creates a new formatter with a file as the sink, using the specified
        charset
	public Formatter(String fileName, String csn);
	
	// Same as above, but with a locale
	public Formatter(String fileName, String csn, Locale l);	

This is a pretty wide range ...