There are two kinds of printing:
- When you know the brand of printer you have and the control codes it likes, and
you want to send raw bytes to it. Most often you want to do this when your
printer handles PostScript.
- You don’t know what kind of printer you have. You want to use generic
methods and have the operating system convert them into the codes the printer
likes. For this technique to work, the printer must be configured in the OS with
a device driver, and be accessible to your program as the default printer.
For the rest of this discussion, I will be mostly referring to the second type
printing. Within that, there are three different APIs to choose from.
- Since Java 1.1: java.awt.PrintJob and related
classes.
- Since Java 1.2: java.awt.print packages.
- In Java 1.3: significant enhancements to both packages.
- Since Java 1.4: The Java Print Service (JPS) javax.print
packages. This is mainly to add support for printing in tiny hand held devices.
Programmers were not happy with the AWT print interface and Sun has made been
several attempts to replace the API. This has mainly lead to confusion. The key
is to get clear on just which printing API you are using and stick to it.
The Java 1.0 JDK does not support printing. JDK 1.1 does, via java.awt.PrintJob.
You print using the same techniques you use for drawing on the screen. It is
much like drawing a high-res screen the size of a sheet of paper. Components now
have a print method to print themselves which is usually the same as the one to
draw them on the screen. To handle text you use Canvases and drawString, or
TextFields. To get properly aligned text without borders, consider the KL-Group
components or Swing.
In JDK 1.1 unsigned Applets could not print. In more recent versions, they can,
though the user has to give an ok.
How To Use PrintJob
For example to print everything in a frame:
In Win95 and NT, the print job properties are ignored. They are system dependent.
But here is how Sun implements them:
How To Use PrinterJob
Java 1.2+ PrinterJob is similar to PrintJob.
It pops up a platform specific dialog box that the end user fills in to select
options.
I don’t know how you go about setting attributes that the end user would
otherwise have to select in the dialog.
Attributes
Sun’s Javadoc on the
Printing Attributes class : available:
Designing Printouts
Here is a little PostScript grid.ps
program.
copy grid.ps lpt1:
(where lpt1: is a PostScript printer) to print out a 1/10" by 1/6"
grid on transparent film. It will be useful in designing or checking printouts,
especially those on pre-printed forms.
Faster Printing with javax.print
Dot matrix printing is especially slow. To be quick, you must send text
intermixed with printer-specific formatting commands. You can do that with RTextPrinter.
The following hunk of code presumes you have already, through some other process,
created a file file.ps full of PostScript printer
commands and you want to get it printed on a printer that can print five double-sided
copies on size A4 paper.
Learning More
Sun’s Javadoc on
java.
awt.PrintJob : available:
Sun’s Javadoc on
java.
awt.print.PrinterJob : available:
Sun’s JDK Technote Guide on
Java Print Service : available:
Sun’s Javadoc on the
PrintRequestAttributeSet class : available:
Sun’s Javadoc on the
HashPrintRequestAttributeSet class : available:
by Roedy Green ©1996-2008 Canadian Mind Products
Please email your feedback for publication, errors, omissions, broken/redirected link reports
