001    /* StreamPrintServiceFactory.java -- 
002       Copyright (C) 2006 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.print;
040    
041    import gnu.classpath.ServiceFactory;
042    
043    import java.io.OutputStream;
044    import java.util.Arrays;
045    import java.util.HashSet;
046    import java.util.Iterator;
047    
048    /**
049     * <code>StreamPrintServiceFactory</code> provides a static method to lookup 
050     * registered factories to construct <code>StreamPrintService</code> instances.
051     * <p>
052     * <code>StreamPrintService</code> are used to print into a provided output 
053     * stream in the document format provided by the stream print service 
054     * implementation.
055     * </p><p>
056     * Implementations are located and loaded automatically through the SPI JAR 
057     * file specification. Therefore implementation classes must provide a default 
058     * constructor for instantiation.
059     * </p>
060     * 
061     * @author Wolfgang Baer (WBaer@gmx.de)
062     */
063    public abstract class StreamPrintServiceFactory
064    {   
065      /**
066       * Default public constructor.
067       * Used for automatic loading and instantiation through 
068       * the SPI jar file specification.
069       */
070      public StreamPrintServiceFactory()
071      {
072        // nothing to do
073      }
074      
075      /**
076       * Searches for matching factories providing stream print services that  
077       * support the printing of documents with the given document flavor into 
078       * the given output mime type.
079       * 
080       * @param flavor the document flavor needed, <code>null</code> doesn't 
081       * constrain the lookup result.
082       * @param outputMimeType the mime type needed, <code>null</code> doesn't 
083       * constrain the lookup result.
084       * 
085       * @return The matching <code>StreamPrintServiceFactory</code> instances.
086       */
087      public static StreamPrintServiceFactory[] lookupStreamPrintServiceFactories(
088        DocFlavor flavor, String outputMimeType)
089      {
090        HashSet set = new HashSet();
091        
092        Iterator it = 
093          ServiceFactory.lookupProviders(StreamPrintServiceFactory.class);
094        
095        while (it.hasNext())
096          {
097            StreamPrintServiceFactory tmp = (StreamPrintServiceFactory) it.next();
098            if (tmp.getOutputFormat().equals(outputMimeType)
099                && Arrays.asList(tmp.getSupportedDocFlavors()).contains(flavor))
100              set.add(tmp);          
101          }
102        
103        StreamPrintServiceFactory[] tmp = new StreamPrintServiceFactory[set.size()];
104        return (StreamPrintServiceFactory[]) set.toArray(tmp);  
105      } 
106      
107      /**
108       * Returns the output format supported by this factory.
109       * 
110       * @return The mime type of the output format as string representation.
111       */
112      public abstract String getOutputFormat();
113      
114      /**
115       * Returns the document flavors this factory supports as flavors
116       * for the input documents.
117       * 
118       * @return The array of supported document flavors.
119       */
120      public abstract DocFlavor[] getSupportedDocFlavors();
121      
122      /**
123       * Constructs a <code>StreamPrintService</code> which directs its output
124       * the given output stream.
125       * 
126       * @param out the output stream for the produced document.
127       * @return The constructed stream print service.
128       */
129      public abstract StreamPrintService getPrintService(OutputStream out);
130    }