src/java.desktop/unix/classes/sun/print/CUPSPrinter.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2003, 2014, 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 sun.print;

 import java.net.URL;
 import java.net.HttpURLConnection;
 import java.io.OutputStream;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.HashMap;
 import sun.print.IPPPrintService;
 import sun.print.CustomMediaSizeName;
 import sun.print.CustomMediaTray;
 import javax.print.attribute.standard.Media;
 import javax.print.attribute.standard.MediaSizeName;
 import javax.print.attribute.standard.MediaSize;
 import javax.print.attribute.standard.MediaTray;
 import javax.print.attribute.standard.MediaPrintableArea;
 import javax.print.attribute.standard.PrinterResolution;
 import javax.print.attribute.Size2DSyntax;
 import javax.print.attribute.Attribute;
 import javax.print.attribute.EnumSyntax;
 import javax.print.attribute.standard.PrinterName;


 public class CUPSPrinter  {
     private static final String debugPrefix = "CUPSPrinter>> ";
     private static final double PRINTER_DPI = 72.0;
     private boolean initialized;
     private static native String getCupsServer();
     private static native int getCupsPort();
     private static native String getCupsDefaultPrinter();
     private static native boolean canConnect(String server, int port);
     private static native boolean initIDs();
     // These functions need to be synchronized as
     // CUPS does not support multi-threading.
     private static synchronized native String[] getMedia(String printer);
     private static synchronized native float[] getPageSizes(String printer);
     private static synchronized native void
         getResolutions(String printer, ArrayList<Integer> resolutionList);
     //public static boolean useIPPMedia = false; will be used later

     private MediaPrintableArea[] cupsMediaPrintables;
     private MediaSizeName[] cupsMediaSNames;
     private CustomMediaSizeName[] cupsCustomMediaSNames;
     private MediaTray[] cupsMediaTrays;

     public  int nPageSizes = 0;
     public  int nTrays = 0;
     private  String[] media;
     private  float[] pageSizes;
     int[]   resolutionsArray;
     private String printer;

     private static boolean libFound;
     private static String cupsServer = null;
     private static int cupsPort = 0;

     static {
         // load awt library to access native code
         java.security.AccessController.doPrivileged(
             new java.security.PrivilegedAction<Void>() {
                 public Void run() {
                     System.loadLibrary("awt");
                     return null;
                 }
             });
         libFound = initIDs();
         if (libFound) {
            cupsServer = getCupsServer();
            cupsPort = getCupsPort();
         }
     }


     CUPSPrinter (String printerName) {
         if (printerName == null) {
             throw new IllegalArgumentException("null printer name");
         }
         printer = printerName;
         cupsMediaSNames = null;
         cupsMediaPrintables = null;
         cupsMediaTrays = null;
         initialized = false;

         if (!libFound) {
             throw new RuntimeException("cups lib not found");
         } else {
             // get page + tray names
             media =  getMedia(printer);
             if (media == null) {
                 // either PPD file is not found or printer is unknown
                 throw new RuntimeException("error getting PPD");
             }

             // get sizes
             pageSizes = getPageSizes(printer);
             if (pageSizes != null) {
                 nPageSizes = pageSizes.length/6;

                 nTrays = media.length/2-nPageSizes;
                 assert (nTrays >= 0);
             }
             ArrayList<Integer> resolutionList = new ArrayList<>();
             getResolutions(printer, resolutionList);
             resolutionsArray = new int[resolutionList.size()];
             for (int i=0; i < resolutionList.size(); i++) {
                 resolutionsArray[i] = resolutionList.get(i);
             }
         }
     }


     /**
      * Returns array of MediaSizeNames derived from PPD.
      */
     MediaSizeName[] getMediaSizeNames() {
         initMedia();
         return cupsMediaSNames;
     }


     /**
      * Returns array of Custom MediaSizeNames derived from PPD.
      */
     CustomMediaSizeName[] getCustomMediaSizeNames() {
         initMedia();
         return cupsCustomMediaSNames;
     }

     public int getDefaultMediaIndex() {
         return ((pageSizes.length >1) ? (int)(pageSizes[pageSizes.length -1]) : 0);
     }

     /**
      * Returns array of MediaPrintableArea derived from PPD.
      */
     MediaPrintableArea[] getMediaPrintableArea() {
         initMedia();
         return cupsMediaPrintables;
     }

     /**
      * Returns array of MediaTrays derived from PPD.
      */
     MediaTray[] getMediaTrays() {
         initMedia();
         return cupsMediaTrays;
     }

     /**
      * return the raw packed array of supported printer resolutions.
      */
     int[] getRawResolutions() {
         return resolutionsArray;
     }

     /**
      * Initialize media by translating PPD info to PrintService attributes.
      */
     private synchronized void initMedia() {
         if (initialized) {
             return;
         } else {
             initialized = true;
         }

         if (pageSizes == null) {
             return;
         }

         cupsMediaPrintables = new MediaPrintableArea[nPageSizes];
         cupsMediaSNames = new MediaSizeName[nPageSizes];
         cupsCustomMediaSNames = new CustomMediaSizeName[nPageSizes];

         CustomMediaSizeName msn;
         MediaPrintableArea mpa;
         float length, width, x, y, w, h;

         // initialize names and printables
         for (int i=0; i<nPageSizes; i++) {
             // media width and length
             width = (float)(pageSizes[i*6]/PRINTER_DPI);
             length = (float)(pageSizes[i*6+1]/PRINTER_DPI);
             // media printable area
             x = (float)(pageSizes[i*6+2]/PRINTER_DPI);
             h = (float)(pageSizes[i*6+3]/PRINTER_DPI);
             w = (float)(pageSizes[i*6+4]/PRINTER_DPI);
             y = (float)(pageSizes[i*6+5]/PRINTER_DPI);

             msn = new CustomMediaSizeName(media[i*2], media[i*2+1],
                                           width, length);

             // add to list of standard MediaSizeNames
             if ((cupsMediaSNames[i] = msn.getStandardMedia()) == null) {
                 // add custom if no matching standard media
                 cupsMediaSNames[i] = msn;

                 // add this new custom msn to MediaSize array
                 if ((width > 0.0) && (length > 0.0)) {
                     try {
                     new MediaSize(width, length,
                                   Size2DSyntax.INCH, msn);
                     } catch (IllegalArgumentException e) {
                         /* PDF printer in Linux for Ledger paper causes
                         "IllegalArgumentException: X dimension > Y dimension".
                         We rotate based on IPP spec. */
                         new MediaSize(length, width, Size2DSyntax.INCH, msn);
                     }
                 }
             }

             // add to list of custom MediaSizeName
             // for internal use of IPPPrintService
             cupsCustomMediaSNames[i] = msn;

             mpa = null;
             try {
                 mpa = new MediaPrintableArea(x, y, w, h,
                                              MediaPrintableArea.INCH);
             } catch (IllegalArgumentException e) {
                 if (width > 0 && length > 0) {
                     mpa = new MediaPrintableArea(0, 0, width, length,
                                              MediaPrintableArea.INCH);
                 }
             }
             cupsMediaPrintables[i] = mpa;
         }

         // initialize trays
         cupsMediaTrays = new MediaTray[nTrays];

         MediaTray mt;
         for (int i=0; i<nTrays; i++) {
             mt = new CustomMediaTray(media[(nPageSizes+i)*2],
                                      media[(nPageSizes+i)*2+1]);
             cupsMediaTrays[i] = mt;
         }

     }

     /**
      * Get CUPS default printer using IPP.
      * Returns 2 values - index 0 is printer name, index 1 is the uri.
      */
     static String[] getDefaultPrinter() {
         // Try to get user/lpoptions-defined printer name from CUPS
         // if not user-set, then go for server default destination
         String printerInfo[] = new String[2];
         printerInfo[0] = getCupsDefaultPrinter();

         if (printerInfo[0] != null) {
             printerInfo[1] = null;
             return printerInfo.clone();
         }
         try {
             URL url = new URL("http", getServer(), getPort(), "");
             final HttpURLConnection urlConnection =
                 IPPPrintService.getIPPConnection(url);

             if (urlConnection != null) {
                 OutputStream os = java.security.AccessController.
                     doPrivileged(new java.security.PrivilegedAction<OutputStream>() {
                         public OutputStream run() {
                             try {
                                 return urlConnection.getOutputStream();
                             } catch (Exception e) {
                                IPPPrintService.debug_println(debugPrefix+e);
                             }
                             return null;
                         }
                     });

                 if (os == null) {
                     return null;
                 }

                 AttributeClass attCl[] = {
                     AttributeClass.ATTRIBUTES_CHARSET,
                     AttributeClass.ATTRIBUTES_NATURAL_LANGUAGE,
                     new AttributeClass("requested-attributes",
                                        AttributeClass.TAG_URI,
                                        "printer-uri")
                 };

                 if (IPPPrintService.writeIPPRequest(os,
                                         IPPPrintService.OP_CUPS_GET_DEFAULT,
                                         attCl)) {

                     HashMap<String, AttributeClass> defaultMap = null;

                     InputStream is = urlConnection.getInputStream();
                     HashMap<String, AttributeClass>[] responseMap = IPPPrintService.readIPPResponse(
                                          is);
                     is.close();

                     if (responseMap != null && responseMap.length > 0) {
                         defaultMap = responseMap[0];
                     } else {
                        IPPPrintService.debug_println(debugPrefix+
                            " empty response map for GET_DEFAULT.");
                     }

                     if (defaultMap == null) {
                         os.close();
                         urlConnection.disconnect();

                         /* CUPS on OS X, as initially configured, considers the
                          * default printer to be the last one used that's
                          * presently available. So if no default was
                          * reported, exec lpstat -d which has all the Apple
                          * special behaviour for this built in.
                          */
                          if (PrintServiceLookupProvider.isMac()) {
                              printerInfo[0] = PrintServiceLookupProvider.
                                                    getDefaultPrinterNameSysV();
                              printerInfo[1] = null;
                              return printerInfo.clone();
                          } else {
                              return null;
                          }
                     }


                     AttributeClass attribClass = defaultMap.get("printer-name");

                     if (attribClass != null) {
                         printerInfo[0] = attribClass.getStringValue();
                         attribClass = defaultMap.get("printer-uri-supported");
                         IPPPrintService.debug_println(debugPrefix+
                           "printer-uri-supported="+attribClass);
                         if (attribClass != null) {
                             printerInfo[1] = attribClass.getStringValue();
                         } else {
                             printerInfo[1] = null;
                         }
                         os.close();
                         urlConnection.disconnect();
                         return printerInfo.clone();
                     }
                 }
                 os.close();
                 urlConnection.disconnect();
             }
         } catch (Exception e) {
         }
         return null;
     }


     /**
      * Get list of all CUPS printers using IPP.
      */
     static String[] getAllPrinters() {
         try {
             URL url = new URL("http", getServer(), getPort(), "");

             final HttpURLConnection urlConnection =
                 IPPPrintService.getIPPConnection(url);

             if (urlConnection != null) {
                 OutputStream os = java.security.AccessController.
                     doPrivileged(new java.security.PrivilegedAction<OutputStream>() {
                         public OutputStream run() {
                             try {
                                 return urlConnection.getOutputStream();
                             } catch (Exception e) {
                             }
                             return null;
                         }
                     });

                 if (os == null) {
                     return null;
                 }

                 AttributeClass attCl[] = {
                     AttributeClass.ATTRIBUTES_CHARSET,
                     AttributeClass.ATTRIBUTES_NATURAL_LANGUAGE,
                     new AttributeClass("requested-attributes",
                                        AttributeClass.TAG_KEYWORD,
                                        "printer-uri-supported")
                 };

                 if (IPPPrintService.writeIPPRequest(os,
                                 IPPPrintService.OP_CUPS_GET_PRINTERS, attCl)) {

                     InputStream is = urlConnection.getInputStream();
                     HashMap<String, AttributeClass>[] responseMap =
                         IPPPrintService.readIPPResponse(is);

                     is.close();
                     os.close();
                     urlConnection.disconnect();

                     if (responseMap == null || responseMap.length == 0) {
                         return null;
                     }

                     ArrayList<String> printerNames = new ArrayList<>();
                     for (int i=0; i< responseMap.length; i++) {
                         AttributeClass attribClass =
                             responseMap[i].get("printer-uri-supported");

                         if (attribClass != null) {
                             String nameStr = attribClass.getStringValue();
                             printerNames.add(nameStr);
                         }
                     }
                     return printerNames.toArray(new String[] {});
                 } else {
                     os.close();
                     urlConnection.disconnect();
                 }
             }

         } catch (Exception e) {
         }
         return null;

     }

     /**
      * Returns CUPS server name.
      */
     public static String getServer() {
         return cupsServer;
     }

     /**
      * Returns CUPS port number.
      */
     public static int getPort() {
         return cupsPort;
     }

     /**
      * Detects if CUPS is running.
      */
     public static boolean isCupsRunning() {
         IPPPrintService.debug_println(debugPrefix+"libFound "+libFound);
         if (libFound) {
             IPPPrintService.debug_println(debugPrefix+"CUPS server "+getServer()+
                                           " port "+getPort());
             return canConnect(getServer(), getPort());
         } else {
             return false;
         }
     }


 }
	/*
	* Copyright (c) 2003, 2014, 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 sun.print;

	import java.net.URL;
	import java.net.HttpURLConnection;
	import java.io.OutputStream;
	import java.io.InputStream;
	import java.util.ArrayList;
	import java.util.HashMap;
	import sun.print.IPPPrintService;
	import sun.print.CustomMediaSizeName;
	import sun.print.CustomMediaTray;
	import javax.print.attribute.standard.Media;
	import javax.print.attribute.standard.MediaSizeName;
	import javax.print.attribute.standard.MediaSize;
	import javax.print.attribute.standard.MediaTray;
	import javax.print.attribute.standard.MediaPrintableArea;
	import javax.print.attribute.standard.PrinterResolution;
	import javax.print.attribute.Size2DSyntax;
	import javax.print.attribute.Attribute;
	import javax.print.attribute.EnumSyntax;
	import javax.print.attribute.standard.PrinterName;


	public class CUPSPrinter {
	private static final String debugPrefix = "CUPSPrinter>> ";
	private static final double PRINTER_DPI = 72.0;
	private boolean initialized;
	private static native String getCupsServer();
	private static native int getCupsPort();
	private static native String getCupsDefaultPrinter();
	private static native boolean canConnect(String server, int port);
	private static native boolean initIDs();
	// These functions need to be synchronized as
	// CUPS does not support multi-threading.
	private static synchronized native String[] getMedia(String printer);
	private static synchronized native float[] getPageSizes(String printer);
	private static synchronized native void
	getResolutions(String printer, ArrayList<Integer> resolutionList);
	//public static boolean useIPPMedia = false; will be used later

	private MediaPrintableArea[] cupsMediaPrintables;
	private MediaSizeName[] cupsMediaSNames;
	private CustomMediaSizeName[] cupsCustomMediaSNames;
	private MediaTray[] cupsMediaTrays;

	public int nPageSizes = 0;
	public int nTrays = 0;
	private String[] media;
	private float[] pageSizes;
	int[] resolutionsArray;
	private String printer;

	private static boolean libFound;
	private static String cupsServer = null;
	private static int cupsPort = 0;

	static {
	// load awt library to access native code
	java.security.AccessController.doPrivileged(
	new java.security.PrivilegedAction<Void>() {
	public Void run() {
	System.loadLibrary("awt");
	return null;
	}
	});
	libFound = initIDs();
	if (libFound) {
	cupsServer = getCupsServer();
	cupsPort = getCupsPort();
	}
	}


	CUPSPrinter (String printerName) {
	if (printerName == null) {
	throw new IllegalArgumentException("null printer name");
	}
	printer = printerName;
	cupsMediaSNames = null;
	cupsMediaPrintables = null;
	cupsMediaTrays = null;
	initialized = false;

	if (!libFound) {
	throw new RuntimeException("cups lib not found");
	} else {
	// get page + tray names
	media = getMedia(printer);
	if (media == null) {
	// either PPD file is not found or printer is unknown
	throw new RuntimeException("error getting PPD");
	}

	// get sizes
	pageSizes = getPageSizes(printer);
	if (pageSizes != null) {
	nPageSizes = pageSizes.length/6;

	nTrays = media.length/2-nPageSizes;
	assert (nTrays >= 0);
	}
	ArrayList<Integer> resolutionList = new ArrayList<>();
	getResolutions(printer, resolutionList);
	resolutionsArray = new int[resolutionList.size()];
	for (int i=0; i < resolutionList.size(); i++) {
	resolutionsArray[i] = resolutionList.get(i);
	}
	}
	}


	/**
	* Returns array of MediaSizeNames derived from PPD.
	*/
	MediaSizeName[] getMediaSizeNames() {
	initMedia();
	return cupsMediaSNames;
	}


	/**
	* Returns array of Custom MediaSizeNames derived from PPD.
	*/
	CustomMediaSizeName[] getCustomMediaSizeNames() {
	initMedia();
	return cupsCustomMediaSNames;
	}

	public int getDefaultMediaIndex() {
	return ((pageSizes.length >1) ? (int)(pageSizes[pageSizes.length -1]) : 0);
	}

	/**
	* Returns array of MediaPrintableArea derived from PPD.
	*/
	MediaPrintableArea[] getMediaPrintableArea() {
	initMedia();
	return cupsMediaPrintables;
	}

	/**
	* Returns array of MediaTrays derived from PPD.
	*/
	MediaTray[] getMediaTrays() {
	initMedia();
	return cupsMediaTrays;
	}

	/**
	* return the raw packed array of supported printer resolutions.
	*/
	int[] getRawResolutions() {
	return resolutionsArray;
	}

	/**
	* Initialize media by translating PPD info to PrintService attributes.
	*/
	private synchronized void initMedia() {
	if (initialized) {
	return;
	} else {
	initialized = true;
	}

	if (pageSizes == null) {
	return;
	}

	cupsMediaPrintables = new MediaPrintableArea[nPageSizes];
	cupsMediaSNames = new MediaSizeName[nPageSizes];
	cupsCustomMediaSNames = new CustomMediaSizeName[nPageSizes];

	CustomMediaSizeName msn;
	MediaPrintableArea mpa;
	float length, width, x, y, w, h;

	// initialize names and printables
	for (int i=0; i<nPageSizes; i++) {
	// media width and length
	width = (float)(pageSizes[i*6]/PRINTER_DPI);
	length = (float)(pageSizes[i*6+1]/PRINTER_DPI);
	// media printable area
	x = (float)(pageSizes[i*6+2]/PRINTER_DPI);
	h = (float)(pageSizes[i*6+3]/PRINTER_DPI);
	w = (float)(pageSizes[i*6+4]/PRINTER_DPI);
	y = (float)(pageSizes[i*6+5]/PRINTER_DPI);

	msn = new CustomMediaSizeName(media[i2], media[i2+1],
	width, length);

	// add to list of standard MediaSizeNames
	if ((cupsMediaSNames[i] = msn.getStandardMedia()) == null) {
	// add custom if no matching standard media
	cupsMediaSNames[i] = msn;

	// add this new custom msn to MediaSize array
	if ((width > 0.0) && (length > 0.0)) {
	try {
	new MediaSize(width, length,
	Size2DSyntax.INCH, msn);
	} catch (IllegalArgumentException e) {
	/* PDF printer in Linux for Ledger paper causes
	"IllegalArgumentException: X dimension > Y dimension".
	We rotate based on IPP spec. */
	new MediaSize(length, width, Size2DSyntax.INCH, msn);
	}
	}
	}

	// add to list of custom MediaSizeName
	// for internal use of IPPPrintService
	cupsCustomMediaSNames[i] = msn;

	mpa = null;
	try {
	mpa = new MediaPrintableArea(x, y, w, h,
	MediaPrintableArea.INCH);
	} catch (IllegalArgumentException e) {
	if (width > 0 && length > 0) {
	mpa = new MediaPrintableArea(0, 0, width, length,
	MediaPrintableArea.INCH);
	}
	}
	cupsMediaPrintables[i] = mpa;
	}

	// initialize trays
	cupsMediaTrays = new MediaTray[nTrays];

	MediaTray mt;
	for (int i=0; i<nTrays; i++) {
	mt = new CustomMediaTray(media[(nPageSizes+i)*2],
	media[(nPageSizes+i)*2+1]);
	cupsMediaTrays[i] = mt;
	}

	}

	/**
	* Get CUPS default printer using IPP.
	* Returns 2 values - index 0 is printer name, index 1 is the uri.
	*/
	static String[] getDefaultPrinter() {
	// Try to get user/lpoptions-defined printer name from CUPS
	// if not user-set, then go for server default destination
	String printerInfo[] = new String[2];
	printerInfo[0] = getCupsDefaultPrinter();

	if (printerInfo[0] != null) {
	printerInfo[1] = null;
	return printerInfo.clone();
	}
	try {
	URL url = new URL("http", getServer(), getPort(), "");
	final HttpURLConnection urlConnection =
	IPPPrintService.getIPPConnection(url);

	if (urlConnection != null) {
	OutputStream os = java.security.AccessController.
	doPrivileged(new java.security.PrivilegedAction<OutputStream>() {
	public OutputStream run() {
	try {
	return urlConnection.getOutputStream();
	} catch (Exception e) {
	IPPPrintService.debug_println(debugPrefix+e);
	}
	return null;
	}
	});

	if (os == null) {
	return null;
	}

	AttributeClass attCl[] = {
	AttributeClass.ATTRIBUTES_CHARSET,
	AttributeClass.ATTRIBUTES_NATURAL_LANGUAGE,
	new AttributeClass("requested-attributes",
	AttributeClass.TAG_URI,
	"printer-uri")
	};

	if (IPPPrintService.writeIPPRequest(os,
	IPPPrintService.OP_CUPS_GET_DEFAULT,
	attCl)) {

	HashMap<String, AttributeClass> defaultMap = null;

	InputStream is = urlConnection.getInputStream();
	HashMap<String, AttributeClass>[] responseMap = IPPPrintService.readIPPResponse(
	is);
	is.close();

	if (responseMap != null && responseMap.length > 0) {
	defaultMap = responseMap[0];
	} else {
	IPPPrintService.debug_println(debugPrefix+
	" empty response map for GET_DEFAULT.");
	}

	if (defaultMap == null) {
	os.close();
	urlConnection.disconnect();

	/* CUPS on OS X, as initially configured, considers the
	* default printer to be the last one used that's
	* presently available. So if no default was
	* reported, exec lpstat -d which has all the Apple
	* special behaviour for this built in.
	*/
	if (PrintServiceLookupProvider.isMac()) {
	printerInfo[0] = PrintServiceLookupProvider.
	getDefaultPrinterNameSysV();
	printerInfo[1] = null;
	return printerInfo.clone();
	} else {
	return null;
	}
	}


	AttributeClass attribClass = defaultMap.get("printer-name");

	if (attribClass != null) {
	printerInfo[0] = attribClass.getStringValue();
	attribClass = defaultMap.get("printer-uri-supported");
	IPPPrintService.debug_println(debugPrefix+
	"printer-uri-supported="+attribClass);
	if (attribClass != null) {
	printerInfo[1] = attribClass.getStringValue();
	} else {
	printerInfo[1] = null;
	}
	os.close();
	urlConnection.disconnect();
	return printerInfo.clone();
	}
	}
	os.close();
	urlConnection.disconnect();
	}
	} catch (Exception e) {
	}
	return null;
	}


	/**
	* Get list of all CUPS printers using IPP.
	*/
	static String[] getAllPrinters() {
	try {
	URL url = new URL("http", getServer(), getPort(), "");

	final HttpURLConnection urlConnection =
	IPPPrintService.getIPPConnection(url);

	if (urlConnection != null) {
	OutputStream os = java.security.AccessController.
	doPrivileged(new java.security.PrivilegedAction<OutputStream>() {
	public OutputStream run() {
	try {
	return urlConnection.getOutputStream();
	} catch (Exception e) {
	}
	return null;
	}
	});

	if (os == null) {
	return null;
	}

	AttributeClass attCl[] = {
	AttributeClass.ATTRIBUTES_CHARSET,
	AttributeClass.ATTRIBUTES_NATURAL_LANGUAGE,
	new AttributeClass("requested-attributes",
	AttributeClass.TAG_KEYWORD,
	"printer-uri-supported")
	};

	if (IPPPrintService.writeIPPRequest(os,
	IPPPrintService.OP_CUPS_GET_PRINTERS, attCl)) {

	InputStream is = urlConnection.getInputStream();
	HashMap<String, AttributeClass>[] responseMap =
	IPPPrintService.readIPPResponse(is);

	is.close();
	os.close();
	urlConnection.disconnect();

	if (responseMap == null \|\| responseMap.length == 0) {
	return null;
	}

	ArrayList<String> printerNames = new ArrayList<>();
	for (int i=0; i< responseMap.length; i++) {
	AttributeClass attribClass =
	responseMap[i].get("printer-uri-supported");

	if (attribClass != null) {
	String nameStr = attribClass.getStringValue();
	printerNames.add(nameStr);
	}
	}
	return printerNames.toArray(new String[] {});
	} else {
	os.close();
	urlConnection.disconnect();
	}
	}

	} catch (Exception e) {
	}
	return null;

	}

	/**
	* Returns CUPS server name.
	*/
	public static String getServer() {
	return cupsServer;
	}

	/**
	* Returns CUPS port number.
	*/
	public static int getPort() {
	return cupsPort;
	}

	/**
	* Detects if CUPS is running.
	*/
	public static boolean isCupsRunning() {
	IPPPrintService.debug_println(debugPrefix+"libFound "+libFound);
	if (libFound) {
	IPPPrintService.debug_println(debugPrefix+"CUPS server "+getServer()+
	" port "+getPort());
	return canConnect(getServer(), getPort());
	} else {
	return false;
	}
	}


	}