eu.etaxonomy.taxeditor.editor/src/main/java/eu/etaxonomy/taxeditor/editor/CdmDataTransfer.java

   1 // $Id$
   2 /**
   3 * Copyright (C) 2007 EDIT
   4 * European Distributed Institute of Taxonomy
   5 * http://www.e-taxonomy.eu
   6 *
   7 * The contents of this file are subject to the Mozilla Public License Version 1.1
   8 * See LICENSE.TXT at the top of this package for the full license terms.
   9 */
  10
  11 package eu.etaxonomy.taxeditor.editor;
  12
  13 import java.io.ByteArrayInputStream;
  14 import java.io.ByteArrayOutputStream;
  15 import java.io.DataInputStream;
  16 import java.io.DataOutputStream;
  17 import java.io.EOFException;
  18 import java.io.IOException;
  19 import java.util.ArrayList;
  20 import java.util.List;
  21 import java.util.UUID;
  22
  23 import org.apache.log4j.Logger;
  24 import org.eclipse.swt.dnd.ByteArrayTransfer;
  25 import org.eclipse.swt.dnd.TransferData;
  26
  27 import eu.etaxonomy.cdm.api.service.ITaxonService;
  28 import eu.etaxonomy.cdm.model.common.ICdmBase;
  29 import eu.etaxonomy.cdm.model.taxon.Synonym;
  30 import eu.etaxonomy.cdm.model.taxon.Taxon;
  31 import eu.etaxonomy.taxeditor.store.CdmStore;
  32
  33 /**
  34  * <p>CdmDataTransfer class.</p>
  35  *
  36  * @author n.hoffmann
  37  * @created Jun 18, 2010
  38  * @version 1.0
  39  */
  40 public class CdmDataTransfer extends ByteArrayTransfer {
  41         private static final Logger logger = Logger
  42                         .getLogger(CdmDataTransfer.class);
  43
  44         private static int SEPARATOR = -10;
  45         private static int EOF = -20;
  46         private static final String TYPE_NAME = "cdmdata-transfer-format";
  47         private static final int TYPE_ID = registerType (TYPE_NAME);
  48         private static final CdmDataTransfer instance = new CdmDataTransfer();
  49
  50         /**
  51          * <p>Getter for the field <code>instance</code>.</p>
  52          *
  53          * @return a {@link eu.etaxonomy.taxeditor.editor.CdmDataTransfer} object.
  54          */
  55         public static synchronized CdmDataTransfer getInstance() {
  56                 return instance;
  57         }
  58
  59         private ICdmBase cdmBase;
  60
  61         /* (non-Javadoc)
  62          * @see org.eclipse.swt.dnd.Transfer#getTypeIds()
  63          */
  64         /** {@inheritDoc} */
  65         @Override
  66         protected int[] getTypeIds() {
  67                 return new int[] { TYPE_ID };
  68         }
  69
  70         /* (non-Javadoc)
  71          * @see org.eclipse.swt.dnd.Transfer#getTypeNames()
  72          */
  73         /** {@inheritDoc} */
  74         @Override
  75         protected String[] getTypeNames() {
  76                 return new String[]{ TYPE_NAME };
  77         }
  78
  79         /** {@inheritDoc} */
  80         @Override
  81         protected void javaToNative(Object object, TransferData transferData) {
  82                 byte[] bytes = toByteArray((ICdmBase[]) object);
  83                 if (bytes != null)
  84                         super.javaToNative(bytes, transferData);
  85         }
  86
  87
  88
  89         /** {@inheritDoc} */
  90         @Override
  91         protected Object nativeToJava(TransferData transferData) {
  92                 byte[] bytes = (byte[]) super.nativeToJava(transferData);
  93                 return fromByteArray(bytes);
  94         }
  95
  96
  97         private byte[] toByteArray(ICdmBase[] cdmBaseObjects) {
  98                 /**
  99                  * Transfer data is an array of gadgets. Serialized version is: (int)
 100                  * number of gadgets (Gadget) gadget 1 (Gadget) gadget 2 ... repeat for
 101                  * each subsequent gadget see writeGadget for the (Gadget) format.
 102                  */
 103                 ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
 104                 DataOutputStream out = new DataOutputStream(byteOut);
 105
 106                 byte[] bytes = null;
 107
 108                 try {
 109
 110                         for(ICdmBase cdmBaseObject : cdmBaseObjects){
 111                                 writeCdmBaseObject(cdmBaseObject, out);
 112                         }
 113                         out.close();
 114                         bytes = byteOut.toByteArray();
 115                 } catch (IOException e) {
 116                         // when in doubt send nothing
 117                 }
 118                 return bytes;
 119         }
 120
 121
 122         private ICdmBase[] fromByteArray(byte[] bytes) {
 123                 DataInputStream in = new DataInputStream(new ByteArrayInputStream(bytes));
 124
 125                 try {
 126                         List<ICdmBase> cdmBaseObjects = new ArrayList<ICdmBase>();
 127
 128                         try{
 129                                 while(true){
 130                                         cdmBaseObjects.add(readCdmBaseObject(in));
 131                                 }
 132                         }catch(EOFException e){
 133                                 return cdmBaseObjects.toArray(new ICdmBase[]{});
 134                         }
 135                 } catch (IOException e) {
 136                         return null;
 137                 }
 138         }
 139
 140         private ICdmBase readCdmBaseObject(DataInputStream in) throws IOException{
 141                 String className = in.readUTF();
 142                 in.readInt();
 143                 String idString = in.readUTF();
 144                 in.readInt();
 145
 146                 if(className.equals(Synonym.class.getName()) || className.equals(Taxon.class.getName())){
 147                         ICdmBase object = CdmStore.getService(ITaxonService.class).load(UUID.fromString(idString));
 148
 149                         if(object == null){
 150                                 return cdmBase;
 151                         }
 152
 153                         return object;
 154                 }
 155
 156                 return null;
 157         }
 158
 159         private void writeCdmBaseObject(ICdmBase cdmBase, DataOutputStream out) throws IOException{
 160                 /**
 161                  * CdmBase object serialization:
 162                  *
 163                  */
 164                 out.writeUTF(cdmBase.getClass().getName());
 165                 out.writeInt(SEPARATOR);
 166                 out.writeUTF(cdmBase.getUuid().toString());
 167                 out.writeInt(EOF);
 168
 169                 if(cdmBase.getId() == 0){
 170                         // fallback for unsaved instances
 171                         this.cdmBase = cdmBase;
 172                 }
 173         }
 174
 175 }