1 /*
   2  * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.print;
  27 
  28 import java.io.OutputStream;
  29 import java.util.ArrayList;
  30 import java.util.Iterator;
  31 import java.util.ServiceConfigurationError;
  32 import java.util.ServiceLoader;
  33 
  34 import javax.print.attribute.PrintRequestAttributeSet;
  35 
  36 import sun.awt.AppContext;
  37 
  38 /**
  39  * A {@code StreamPrintServiceFactory} is the factory for
  40  * {@link StreamPrintService} instances, which can print to an output stream in
  41  * a particular document format described as a mime type. A typical output
  42  * document format may be Postscript(TM).
  43  * <p>
  44  * This class is implemented by a service and located by the implementation
  45  * using the {@link ServiceLoader} facility.
  46  * <p>
  47  * Applications locate instances of this class by calling the
  48  * {@link #lookupStreamPrintServiceFactories(DocFlavor, String)} method.
  49  * <p>
  50  * Applications can use a {@code StreamPrintService} obtained from a factory in
  51  * place of a {@code PrintService} which represents a physical printer device.
  52  */
  53 public abstract class StreamPrintServiceFactory {
  54 
  55     /**
  56      * Contains a list of factories.
  57      */
  58     static class Services {
  59 
  60         /**
  61          * The list of factories which will be stored per appcontext.
  62          */
  63         private ArrayList<StreamPrintServiceFactory> listOfFactories = null;
  64     }
  65 
  66     /**
  67      * Returns the services from the current appcontext.
  68      *
  69      * @return the services
  70      */
  71     private static Services getServices() {
  72         Services services =
  73             (Services)AppContext.getAppContext().get(Services.class);
  74         if (services == null) {
  75             services = new Services();
  76             AppContext.getAppContext().put(Services.class, services);
  77         }
  78         return services;
  79     }
  80 
  81     /**
  82      * Returns the list of factories.
  83      *
  84      * @return the list of factories
  85      */
  86     private static ArrayList<StreamPrintServiceFactory> getListOfFactories() {
  87         return getServices().listOfFactories;
  88     }
  89 
  90     /**
  91      * Initialize the list of factories.
  92      *
  93      * @return the list of factories
  94      */
  95     private static ArrayList<StreamPrintServiceFactory> initListOfFactories() {
  96         ArrayList<StreamPrintServiceFactory> listOfFactories = new ArrayList<>();
  97         getServices().listOfFactories = listOfFactories;
  98         return listOfFactories;
  99     }
 100 
 101     /**
 102      * Locates factories for print services that can be used with a print job to
 103      * output a stream of data in the format specified by
 104      * {@code outputMimeType}.
 105      * <p>
 106      * The {@code outputMimeType} parameter describes the document type that you
 107      * want to create, whereas the {@code flavor} parameter describes the format
 108      * in which the input data will be provided by the application to the
 109      * {@code StreamPrintService}.
 110      * <p>
 111      * Although {@code null} is an acceptable value to use in the lookup of
 112      * stream printing services, it's typical to search for a particular desired
 113      * format, such as Postscript(TM).
 114      *
 115      * @param  flavor of the input document type - {@code null} means match all
 116      *         types
 117      * @param  outputMimeType representing the required output format, used to
 118      *         identify suitable stream printer factories. A value of
 119      *         {@code null} means match all formats.
 120      * @return matching factories for stream print service instance, empty if no
 121      *         suitable factories could be located
 122      */
 123      public static StreamPrintServiceFactory[]
 124          lookupStreamPrintServiceFactories(DocFlavor flavor,
 125                                            String outputMimeType) {
 126 
 127          ArrayList<StreamPrintServiceFactory> list = getFactories(flavor, outputMimeType);
 128          return list.toArray(new StreamPrintServiceFactory[list.size()]);
 129      }
 130 
 131     /**
 132      * Queries the factory for the document format that is emitted by printers
 133      * obtained from this factory.
 134      *
 135      * @return the output format described as a mime type
 136      */
 137     public abstract String getOutputFormat();
 138 
 139     /**
 140      * Queries the factory for the document flavors that can be accepted by
 141      * printers obtained from this factory.
 142      *
 143      * @return array of supported doc flavors
 144      */
 145     public abstract DocFlavor[] getSupportedDocFlavors();
 146 
 147     /**
 148      * Returns a {@code StreamPrintService} that can print to the specified
 149      * output stream. The output stream is created and managed by the
 150      * application. It is the application's responsibility to close the stream
 151      * and to ensure that this {@code Printer} is not reused. The application
 152      * should not close this stream until any print job created from the printer
 153      * is complete. Doing so earlier may generate a {@code PrinterException} and
 154      * an event indicating that the job failed.
 155      * <p>
 156      * Whereas a {@code PrintService} connected to a physical printer can be
 157      * reused, a {@code StreamPrintService} connected to a stream cannot. The
 158      * underlying {@code StreamPrintService} may be disposed by the print system
 159      * with the {@link StreamPrintService#dispose() dispose} method before
 160      * returning from the
 161      * {@link DocPrintJob#print(Doc, PrintRequestAttributeSet) print} method of
 162      * {@code DocPrintJob} so that the print system knows this printer is no
 163      * longer usable. This is equivalent to a physical printer going offline -
 164      * permanently. Applications may supply a {@code null} print stream to
 165      * create a queryable service. It is not valid to create a {@code PrintJob}
 166      * for such a stream. Implementations which allocate resources on
 167      * construction should examine the stream and may wish to only allocate
 168      * resources if the stream is {@code non-null}.
 169      *
 170      * @param  out destination stream for generated output
 171      * @return a {@code PrintService} which will generate the format specified
 172      *         by the {@code DocFlavor} supported by this factory
 173      */
 174     public abstract StreamPrintService getPrintService(OutputStream out);
 175 
 176     /**
 177      * Returns all factories for print services.
 178      *
 179      * @return all factories
 180      */
 181     private static ArrayList<StreamPrintServiceFactory> getAllFactories() {
 182         synchronized (StreamPrintServiceFactory.class) {
 183 
 184           ArrayList<StreamPrintServiceFactory> listOfFactories = getListOfFactories();
 185             if (listOfFactories != null) {
 186                 return listOfFactories;
 187             } else {
 188                 listOfFactories = initListOfFactories();
 189             }
 190 
 191             try {
 192                 java.security.AccessController.doPrivileged(
 193                      new java.security.PrivilegedExceptionAction<Object>() {
 194                         public Object run() {
 195                             Iterator<StreamPrintServiceFactory> iterator =
 196                                 ServiceLoader.load
 197                                 (StreamPrintServiceFactory.class).iterator();
 198                             ArrayList<StreamPrintServiceFactory> lof = getListOfFactories();
 199                             while (iterator.hasNext()) {
 200                                 try {
 201                                     lof.add(iterator.next());
 202                                 }  catch (ServiceConfigurationError err) {
 203                                      /* In the applet case, we continue */
 204                                     if (System.getSecurityManager() != null) {
 205                                         err.printStackTrace();
 206                                     } else {
 207                                         throw err;
 208                                     }
 209                                 }
 210                             }
 211                             return null;
 212                         }
 213                 });
 214             } catch (java.security.PrivilegedActionException e) {
 215             }
 216             return listOfFactories;
 217         }
 218     }
 219 
 220     /**
 221      * Checks if the array of {@code flavors} contains the {@code flavor}
 222      * object.
 223      *
 224      * @param  flavor the flavor
 225      * @param  flavors the array of flavors
 226      * @return {@code true} if {@code flavors} contains the {@code flavor}
 227      *         object; {@code false} otherwise
 228      */
 229     private static boolean isMember(DocFlavor flavor, DocFlavor[] flavors) {
 230         for (int f=0; f<flavors.length; f++ ) {
 231             if (flavor.equals(flavors[f])) {
 232                 return true;
 233             }
 234         }
 235         return false;
 236     }
 237 
 238     /**
 239      * Utility method for {@link #lookupStreamPrintServiceFactories}.
 240      * <p>
 241      * Locates factories for print services that can be used with a print job to
 242      * output a stream of data in the format specified by
 243      * {@code outputMimeType}.
 244      *
 245      * @param  flavor of the input document type - {@code null} means match all
 246      *         types
 247      * @param  outType representing the required output format, used to identify
 248      *         suitable stream printer factories. A value of {@code null} means
 249      *         match all formats.
 250      * @return matching factories for stream print service instance, empty if no
 251      *         suitable factories could be located
 252      */
 253     private static ArrayList<StreamPrintServiceFactory> getFactories(DocFlavor flavor, String outType) {
 254 
 255         if (flavor == null && outType == null) {
 256             return getAllFactories();
 257         }
 258 
 259         ArrayList<StreamPrintServiceFactory> list = new ArrayList<>();
 260         Iterator<StreamPrintServiceFactory> iterator = getAllFactories().iterator();
 261         while (iterator.hasNext()) {
 262             StreamPrintServiceFactory factory = iterator.next();
 263             if ((outType == null ||
 264                  outType.equalsIgnoreCase(factory.getOutputFormat())) &&
 265                 (flavor == null ||
 266                  isMember(flavor, factory.getSupportedDocFlavors()))) {
 267                 list.add(factory);
 268             }
 269         }
 270 
 271         return list;
 272     }
 273 }