Package javax.print

Provides the principal classes and interfaces for the Java 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 ServiceLoader facility.

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 capabilities, 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:

1. Chooses a DocFlavor.
2. Creates a set of attributes.
3. Locates a print service that can handle the print request as specified by the DocFlavor and the attribute set.
4. 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.
5. Gets a print job, represented by DocPrintJob, from the print service.
6. 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(MediaSizeName.ISO_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.