Java Cookbook

Printing: JDK 1.1

Problem

You need to generate hardcopy, and you’re using JDK 1.1.

Solution

Use java.awt.PrintJob . Or, upgrade to JDK 1.2.

Discussion

The JDK 1.1 API puts your program in the driver’s seat: you decide what to print and when to print it. But first, you have to let the user pick a printer, which you can do by calling the Toolkit method getPrinterJob( ). This pops up a platform-specific print chooser dialog, and if the user picks a printer, you get back a PrintJob object (otherwise you get back null). Your program is in charge of pagination (breaking the data into pages) and drawing each page onto a print buffer. How? For each page you want to print, call the PrintJob ’s getGraphics( ) method to retrieve a Graphics object. Use it as you will; any of its draw or fill methods will draw, not to the screen, but onto paper. Your best bet is to pass it to your paint( ) method, if you have one. This is one of the few places where you do call paint( ) directly. When the page is done, call the Graphics object’s dispose( ) method. When the whole print job is done, call the PrintJob’s end( ) method, and you’re finished -- the data is on its way to the printer.

Here’s a little program that displays a simple graphical component called a DemoGFXCanvas. When you click the Print button at the bottom, the program prints the contents of the DemoGFXCanvas (this is shown graphically in Figure 12-6). When you click on the Print button in the main window, the printer dialog shown at ...