Provides the principal classes and interfaces for the
Java
TM Print Service API.
The Java Print Service API enables client and server applications to:
- Discover and select print services based on their capabilities
- Specify the format of print data
- Submit print jobs to services that support the document type to
be printed.
Print Service Discovery
An application invokes the static methods of the abstract class
PrintServiceLookup
to locate print
services that have the capabilities to satisfy the application's print
request. For example, to print a double-sided document, the application
first needs to find printers that have the double-sided printing capability.
The JDK includes PrintServiceLookup
implementations that
can locate the standard platform printers. To locate other types of printers,
such as IPP printers or JINI printers, a print-service provider can write
implementations of PrintServiceLookup
. The print-service provider
can dynamically install these PrintServiceLookup
implementations
using the
SPI JAR file specification.
Attribute Definitions
The
javax.print.attribute
and
javax.print.attribute.standard
packages define print attributes, which describe the capabilities of a print
service, specify the requirements of a print job, and track the progress of
a print job.
The javax.print.attribute
package describes the types of attributes and
how they can be collected into sets. The javax.print.attribute.standard
package enumerates all of the standard attributes supported by the API, most
of which are implementations of attributes specified in the IETF Specification,
RFC 2911 Internet Printing Protocol, 1.1: Model and Semantics, dated
September 2000. The attributes specified in javax.print.attribute.standard
include common capabilites, such as: resolution, copies, media sizes,
job priority, and page ranges.
Document Type Specification
The
DocFlavor
class represents the print data
format, such as JPEG or PostScript. A
DocFlavor
object
consists of a MIME type, which describes the format, and a document
representation class name that indicates how the document is delivered
to the printer or output stream. An application uses the
DocFlavor
and an attribute set to find printers that can
print the document type specified by the
DocFlavor
and have
the capabilities specified by the attribute set.
Using the API
A typical application using the Java Print Service API performs these steps
to process a print request:
- Chooses a
DocFlavor
.
- Creates a set of attributes.
- Locates a print service that can handle the print request as specified
by the
DocFlavor
and the attribute set.
- Creates a
Doc
object encapsulating the
DocFlavor
and the actual print data, which can take many forms including: a Postscript
file, a JPEG image, a URL, or plain text.
- Gets a print job, represented by
DocPrintJob
,
from the print service.
- Calls the print method of the print job.
The following code sample demonstrates a typical use of the Java Print
Service API: locating printers that can print five double-sided copies
of a Postscript document on size A4 paper, creating a print job from
one of the returned print services, and calling print.
FileInputStream psStream;
try {
psStream = new FileInputStream("file.ps");
} catch (FileNotFoundException ffne) {
}
if (psStream == null) {
return;
}
DocFlavor psInFormat = DocFlavor.INPUT_STREAM.POSTSCRIPT;
Doc myDoc = new SimpleDoc(psStream, psInFormat, null);
PrintRequestAttributeSet aset =
new HashPrintRequestAttributeSet();
aset.add(new Copies(5));
aset.add(MediaSize.A4);
aset.add(Sides.DUPLEX);
PrintService[] services =
PrintServiceLookup.lookupPrintServices(psInFormat, aset);
if (services.length > 0) {
DocPrintJob job = services[0].createPrintJob();
try {
job.print(myDoc, aset);
} catch (PrintException pe) {}
}
Please note: In the javax.print APIs, a null reference parameter to methods
is incorrect unless explicitly documented on the method as having a meaningful
interpretation. Usage to the contrary is incorrect coding and may result
in a run time exception either immediately or at some later time.
IllegalArgumentException and NullPointerException are examples of
typical and acceptable run time exceptions for such cases.