taxeditor-store/src/main/java/eu/etaxonomy/taxeditor/featuretree/FeatureNodeTransfer.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.featuretree;
  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.eclipse.swt.dnd.ByteArrayTransfer;
  24 import org.eclipse.swt.dnd.TransferData;
  25
  26 import eu.etaxonomy.cdm.model.description.FeatureNode;
  27 import eu.etaxonomy.taxeditor.store.CdmStore;
  28
  29 /**
  30  * <p>FeatureNodeTransfer class.</p>
  31  *
  32  * @author n.hoffmann
  33  * @created Aug 5, 2010
  34  * @version 1.0
  35  */
  36 public class FeatureNodeTransfer extends ByteArrayTransfer {
  37
  38         private static FeatureNodeTransfer instance = new FeatureNodeTransfer();
  39         private static final String TYPE_NAME = "featureNode-transfer-format";
  40         private static final int TYPEID = registerType(TYPE_NAME);
  41
  42         /**
  43          * <p>Getter for the field <code>instance</code>.</p>
  44          *
  45          * @return a {@link eu.etaxonomy.taxeditor.featuretree.FeatureNodeTransfer} object.
  46          */
  47         public static synchronized FeatureNodeTransfer getInstance() {
  48                 return instance;
  49         }
  50
  51         private FeatureNodeTransfer() {
  52
  53         }
  54
  55         /** {@inheritDoc} */
  56         @Override
  57         protected int[] getTypeIds() {
  58                 return new int[] { TYPEID };
  59         }
  60
  61         /** {@inheritDoc} */
  62         @Override
  63         protected String[] getTypeNames() {
  64                 return new String[] { TYPE_NAME };
  65         }
  66
  67         /*
  68          * Method declared on Transfer.
  69          */
  70         /** {@inheritDoc} */
  71         protected void javaToNative(Object object, TransferData transferData) {
  72                 byte[] bytes = toByteArray((FeatureNode[]) object);
  73                 if (bytes != null)
  74                         super.javaToNative(bytes, transferData);
  75         }
  76
  77         /*
  78          * Method declared on Transfer.
  79          */
  80         /** {@inheritDoc} */
  81         protected Object nativeToJava(TransferData transferData) {
  82                 byte[] bytes = (byte[]) super.nativeToJava(transferData);
  83                 return fromByteArray(bytes);
  84         }
  85
  86         /**
  87          * <p>toByteArray</p>
  88          *
  89          * @param featureNodes an array of {@link eu.etaxonomy.cdm.model.description.FeatureNode} objects.
  90          * @return an array of byte.
  91          */
  92         protected byte[] toByteArray(FeatureNode[] featureNodes) {
  93                 /**
  94                  * Transfer data is an array of gadgets. Serialized version is: (int)
  95                  * number of gadgets (Gadget) gadget 1 (Gadget) gadget 2 ... repeat for
  96                  * each subsequent gadget see writeGadget for the (Gadget) format.
  97                  */
  98                 ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
  99                 DataOutputStream out = new DataOutputStream(byteOut);
 100
 101                 byte[] bytes = null;
 102
 103                 try {
 104
 105                         for(FeatureNode featureNode : featureNodes){
 106                                 writeFeatureNode(featureNode, out);
 107                         }
 108                         out.close();
 109                         bytes = byteOut.toByteArray();
 110                 } catch (IOException e) {
 111                         // when in doubt send nothing
 112                 }
 113                 return bytes;
 114         }
 115
 116         /**
 117          * <p>fromByteArray</p>
 118          *
 119          * @param bytes an array of byte.
 120          * @return an array of {@link eu.etaxonomy.cdm.model.description.FeatureNode} objects.
 121          */
 122         protected FeatureNode[] fromByteArray(byte[] bytes) {
 123                 DataInputStream in = new DataInputStream(
 124                                 new ByteArrayInputStream(bytes));
 125
 126                 try {
 127                         List<FeatureNode> featureNodes = new ArrayList<FeatureNode>();
 128
 129                         try{
 130                                 while(true){
 131                                         featureNodes.add(readFeatureNode(in));
 132                                 }
 133                         }catch(EOFException e){
 134                                 return featureNodes.toArray(new FeatureNode[]{});
 135                         }
 136                 } catch (IOException e) {
 137                         return null;
 138                 }
 139         }
 140
 141         /**
 142          * Reads and returns a single featureNode from the given stream.
 143          */
 144         private FeatureNode readFeatureNode(DataInputStream dataIn) throws IOException {
 145
 146                 UUID uuid = UUID.fromString(dataIn.readUTF());
 147
 148                 FeatureNode featureNode = CdmStore.getFeatureNodeService().load(uuid);
 149
 150                 return featureNode;
 151         }
 152
 153         /**
 154          * Writes the given featureNode to the stream.
 155          */
 156         private void writeFeatureNode(FeatureNode featureNode,
 157                         DataOutputStream dataOut) throws IOException {
 158                 dataOut.writeUTF(featureNode.getUuid().toString());
 159         }
 160 }