https://openjdk.java.net/ 
/*
 * Copyright (c) 2000, 2007, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.print;

import java.io.OutputStream;

import java.util.ArrayList;
import java.util.Iterator;

import javax.print.DocFlavor;

import sun.awt.AppContext;
import java.util.ServiceLoader;
import java.util.ServiceConfigurationError;


A StreamPrintServiceFactory is the factory for StreamPrintService instances, which can print to an output stream in a particular document format described as a mime type. A typical output document format may be Postscript(TM). 

This class is implemented by a service and located by the
implementation using the

SPI JAR File specification.

 Applications locate instances of this class by calling the lookupStreamPrintServiceFactories(DocFlavor, String) method. 

Applications can use a StreamPrintService obtained from a
factory in place of a PrintService which represents a
physical printer device.

/**
 * A <code>StreamPrintServiceFactory</code> is the factory for
 * {@link StreamPrintService} instances,
 * which can print to an output stream in a particular
 * document format described as a mime type.
 * A typical output document format may be Postscript(TM).
 * <p>
 * This class is implemented by a service and located by the
 * implementation using the
 * <a href="../../../technotes/guides/jar/jar.html#Service Provider">
 * SPI JAR File specification</a>.
 * <p>
 * Applications locate instances of this class by calling the
 * {@link #lookupStreamPrintServiceFactories(DocFlavor, String)} method.
 * <p>
 * Applications can use a <code>StreamPrintService</code> obtained from a
 * factory in place of a <code>PrintService</code> which represents a
 * physical printer device.
 */

public abstract class StreamPrintServiceFactory {

    static class Services {
        private ArrayList listOfFactories = null;
    }

    private static Services getServices() {
        Services services =
            (Services)AppContext.getAppContext().get(Services.class);
        if (services == null) {
            services = new Services();
            AppContext.getAppContext().put(Services.class, services);
        }
        return services;
    }

    private static ArrayList getListOfFactories() {
        return getServices().listOfFactories;
    }

    private static ArrayList initListOfFactories() {
        ArrayList listOfFactories = new ArrayList();
        getServices().listOfFactories = listOfFactories;
        return listOfFactories;
    }

    
Locates factories for print services that can be used with a print job to output a stream of data in the format specified by outputMimeType. 
 The outputMimeType parameter describes the document type that you want to create, whereas the flavor parameter describes the format in which the input data will be provided by the application to the StreamPrintService. 

Although null is an acceptable value to use in the lookup of stream
printing services, it's typical to search for a particular
desired format, such as Postscript(TM).



Params:
  • flavor – of the input document type - null means match all
types.
  • outputMimeType – representing the required output format, used to
identify suitable stream printer factories. A value of null means
match all formats.
Returns:- matching factories for stream print service instance,
          empty if no suitable factories could be located.
/**
     * Locates factories for print services that can be used with
     * a print job to output a stream of data in the
     * format specified by {@code outputMimeType}.
     * <p>
     * The {@code outputMimeType} parameter describes the document type that
     * you want to create, whereas the {@code flavor} parameter describes the
     * format in which the input data will be provided by the application
     * to the {@code StreamPrintService}.
     * <p>
     * Although null is an acceptable value to use in the lookup of stream
     * printing services, it's typical to search for a particular
     * desired format, such as Postscript(TM).
     * <p>
     * @param flavor of the input document type - null means match all
     * types.
     * @param outputMimeType representing the required output format, used to
     * identify suitable stream printer factories. A value of null means
     * match all formats.
     * @return - matching factories for stream print service instance,
     *           empty if no suitable factories could be located.
     */
     public static StreamPrintServiceFactory[]
         lookupStreamPrintServiceFactories(DocFlavor flavor,
                                           String outputMimeType) {

         ArrayList list = getFactories(flavor, outputMimeType);
         return (StreamPrintServiceFactory[])
               (list.toArray(new StreamPrintServiceFactory[list.size()]));
     }

    
Queries the factory for the document format that is emitted
by printers obtained from this factory.

Returns:the output format described as a mime type.
/** Queries the factory for the document format that is emitted
     * by printers obtained from this factory.
     *
     * @return the output format described as a mime type.
     */
    public abstract String getOutputFormat();

    
Queries the factory for the document flavors that can be accepted
by printers obtained from this factory.

Returns:array of supported doc flavors.
/**
     * Queries the factory for the document flavors that can be accepted
     * by printers obtained from this factory.
     * @return array of supported doc flavors.
     */
    public abstract DocFlavor[] getSupportedDocFlavors();

    
Returns a StreamPrintService that can print to
the specified output stream.
The output stream is created and managed by the application.
It is the application's responsibility to close the stream and
to ensure that this Printer is not reused.
The application should not close this stream until any print job
created from the printer is complete. Doing so earlier may generate
a PrinterException and an event indicating that the
job failed.


Whereas a PrintService connected to a physical printer
can be reused,
a StreamPrintService connected to a stream cannot.
The underlying StreamPrintService may be disposed by the print system with the dispose method before returning from the print method of DocPrintJob so that the print system knows
this printer is no longer usable.
This is equivalent to a physical printer going offline - permanently.
Applications may supply a null print stream to create a queryable
service. It is not valid to create a PrintJob for such a stream.
Implementations which allocate resources on construction should examine
the stream and may wish to only allocate resources if the stream is
non-null.



Params:
  • out – destination stream for generated output.
Returns:a PrintService which will generate the format specified by the
DocFlavor supported by this Factory.
/**
     * Returns a <code>StreamPrintService</code> that can print to
     * the specified output stream.
     * The output stream is created and managed by the application.
     * It is the application's responsibility to close the stream and
     * to ensure that this Printer is not reused.
     * The application should not close this stream until any print job
     * created from the printer is complete. Doing so earlier may generate
     * a <code>PrinterException</code> and an event indicating that the
     * job failed.
     * <p>
     * Whereas a <code>PrintService</code> connected to a physical printer
     * can be reused,
     * a <code>StreamPrintService</code> connected to a stream cannot.
     * The underlying <code>StreamPrintService</code> may be disposed by
     * the print system with
     * the {@link StreamPrintService#dispose() dispose} method
     * before returning from the
     * {@link DocPrintJob#print(Doc, javax.print.attribute.PrintRequestAttributeSet) print}
     * method of <code>DocPrintJob</code> so that the print system knows
     * this printer is no longer usable.
     * This is equivalent to a physical printer going offline - permanently.
     * Applications may supply a null print stream to create a queryable
     * service. It is not valid to create a PrintJob for such a stream.
     * Implementations which allocate resources on construction should examine
     * the stream and may wish to only allocate resources if the stream is
     * non-null.
     * <p>
     * @param out destination stream for generated output.
     * @return a PrintService which will generate the format specified by the
     * DocFlavor supported by this Factory.
     */
    public abstract StreamPrintService getPrintService(OutputStream out);


    private static ArrayList getAllFactories() {
        synchronized (StreamPrintServiceFactory.class) {

          ArrayList listOfFactories = getListOfFactories();
            if (listOfFactories != null) {
                return listOfFactories;
            } else {
                listOfFactories = initListOfFactories();
            }

            try {
                java.security.AccessController.doPrivileged(
                     new java.security.PrivilegedExceptionAction() {
                        public Object run() {
                            Iterator<StreamPrintServiceFactory> iterator =
                                ServiceLoader.load
                                (StreamPrintServiceFactory.class).iterator();
                            ArrayList lof = getListOfFactories();
                            while (iterator.hasNext()) {
                                try {
                                    lof.add(iterator.next());
                                }  catch (ServiceConfigurationError err) {
                                     /* In the applet case, we continue */
                                    if (System.getSecurityManager() != null) {
                                        err.printStackTrace();
                                    } else {
                                        throw err;
                                    }
                                }
                            }
                            return null;
                        }
                });
            } catch (java.security.PrivilegedActionException e) {
            }
            return listOfFactories;
        }
    }

    private static boolean isMember(DocFlavor flavor, DocFlavor[] flavors) {
        for (int f=0; f<flavors.length; f++ ) {
            if (flavor.equals(flavors[f])) {
                return true;
            }
        }
        return false;
    }

    private static ArrayList getFactories(DocFlavor flavor, String outType) {

        if (flavor == null && outType == null) {
            return getAllFactories();
        }

        ArrayList list = new ArrayList();
        Iterator iterator = getAllFactories().iterator();
        while (iterator.hasNext()) {
            StreamPrintServiceFactory factory =
                (StreamPrintServiceFactory)iterator.next();
            if ((outType == null ||
                 outType.equalsIgnoreCase(factory.getOutputFormat())) &&
                (flavor == null ||
                 isMember(flavor, factory.getSupportedDocFlavors()))) {
                list.add(factory);
            }
        }

        return list;
    }

}