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