eu.etaxonomy.taxeditor.store/src/main/java/eu/etaxonomy/taxeditor/model/MementoHelper.java

   1 /**
   2 * Copyright (C) 2007 EDIT
   3 * European Distributed Institute of Taxonomy
   4 * http://www.e-taxonomy.eu
   5 *
   6 * The contents of this file are subject to the Mozilla Public License Version 1.1
   7 * See LICENSE.TXT at the top of this package for the full license terms.
   8 */
   9
  10 package eu.etaxonomy.taxeditor.model;
  11
  12 import java.io.BufferedReader;
  13 import java.io.File;
  14 import java.io.FileInputStream;
  15 import java.io.FileNotFoundException;
  16 import java.io.FileOutputStream;
  17 import java.io.IOException;
  18 import java.io.InputStreamReader;
  19 import java.io.OutputStreamWriter;
  20 import java.io.UnsupportedEncodingException;
  21
  22 import org.eclipse.ui.IMemento;
  23 import org.eclipse.ui.WorkbenchException;
  24 import org.eclipse.ui.XMLMemento;
  25
  26
  27 /**
  28  * <p>MementoHelper class.</p>
  29  *
  30  * @author n.hoffmann
  31  * @created Mar 29, 2010
  32  * @version 1.0
  33  */
  34 public class MementoHelper {
  35
  36         /**
  37          * <p>readMementoFromFile</p>
  38          *
  39          * @param stateFile a {@link java.io.File} object.
  40          * @return a org.eclipse.ui.IMemento object.
  41          * @throws java.io.FileNotFoundException if any.
  42          */
  43         public static IMemento readMementoFromFile(File stateFile) throws FileNotFoundException{
  44                 FileInputStream input;
  45                 try {
  46                         input = new FileInputStream(stateFile);
  47                         BufferedReader reader = new BufferedReader(
  48                                         new InputStreamReader(input, "utf-8")); //$NON-NLS-1$
  49                         return XMLMemento.createReadRoot(reader);
  50                 } catch (WorkbenchException e) {
  51                         MessagingUtils.error(MementoHelper.class, "Exception while reading the memento", e);
  52                 } catch (UnsupportedEncodingException e) {
  53                         MessagingUtils.error(MementoHelper.class, "Exception while reading the memento", e);
  54                 }
  55
  56                 return null;
  57         }
  58
  59         /*
  60          * Save the workbench UI in a persistence file.
  61          */
  62         /**
  63          * <p>saveMementoToFile</p>
  64          *
  65          * @param memento a org.eclipse.ui.IMemento object.
  66          * @param stateFile a {@link java.io.File} object.
  67          * @return a org.eclipse.ui.IMemento object.
  68          */
  69         public static IMemento saveMementoToFile(IMemento memento, File stateFile) {
  70                 if (stateFile == null || memento == null) {
  71                         return null;
  72                 }
  73                 try {
  74                         FileOutputStream stream = new FileOutputStream(stateFile);
  75                         OutputStreamWriter writer = new OutputStreamWriter(stream, "utf-8"); //$NON-NLS-1$
  76
  77                         ((XMLMemento)memento).save(writer);
  78
  79                         writer.close();
  80                 } catch (IOException e) {
  81                         stateFile.delete();
  82                         MessagingUtils.error(MementoHelper.class, "Could not save datasource state", e);
  83                         return null;
  84                 }
  85
  86                 // Success !
  87                 return memento;
  88         }
  89 }