eu.etaxonomy.taxeditor.store/src/main/java/eu/etaxonomy/taxeditor/model/MementoHelper.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.model;
  12
  13 import java.io.BufferedReader;
  14 import java.io.File;
  15 import java.io.FileInputStream;
  16 import java.io.FileNotFoundException;
  17 import java.io.FileOutputStream;
  18 import java.io.IOException;
  19 import java.io.InputStreamReader;
  20 import java.io.OutputStreamWriter;
  21 import java.io.UnsupportedEncodingException;
  22
  23 import org.eclipse.ui.IMemento;
  24 import org.eclipse.ui.WorkbenchException;
  25 import org.eclipse.ui.XMLMemento;
  26
  27
  28 /**
  29  * <p>MementoHelper class.</p>
  30  *
  31  * @author n.hoffmann
  32  * @created Mar 29, 2010
  33  * @version 1.0
  34  */
  35 public class MementoHelper {
  36
  37         /**
  38          * <p>readMementoFromFile</p>
  39          *
  40          * @param stateFile a {@link java.io.File} object.
  41          * @return a org.eclipse.ui.IMemento object.
  42          * @throws java.io.FileNotFoundException if any.
  43          */
  44         public static IMemento readMementoFromFile(File stateFile) throws FileNotFoundException{
  45                 FileInputStream input;
  46                 try {
  47                         input = new FileInputStream(stateFile);
  48                         BufferedReader reader = new BufferedReader(
  49                                         new InputStreamReader(input, "utf-8")); //$NON-NLS-1$
  50                         return XMLMemento.createReadRoot(reader);
  51                 } catch (WorkbenchException e) {
  52                         MessagingUtils.error(MementoHelper.class, "Exception while reading the memento", e);
  53                 } catch (UnsupportedEncodingException e) {
  54                         MessagingUtils.error(MementoHelper.class, "Exception while reading the memento", e);
  55                 }
  56
  57                 return null;
  58         }
  59
  60         /*
  61          * Save the workbench UI in a persistence file.
  62          */
  63         /**
  64          * <p>saveMementoToFile</p>
  65          *
  66          * @param memento a org.eclipse.ui.IMemento object.
  67          * @param stateFile a {@link java.io.File} object.
  68          * @return a org.eclipse.ui.IMemento object.
  69          */
  70         public static IMemento saveMementoToFile(IMemento memento, File stateFile) {
  71                 if (stateFile == null || memento == null) {
  72                         return null;
  73                 }
  74                 try {
  75                         FileOutputStream stream = new FileOutputStream(stateFile);
  76                         OutputStreamWriter writer = new OutputStreamWriter(stream, "utf-8"); //$NON-NLS-1$
  77
  78                         ((XMLMemento)memento).save(writer);
  79
  80                         writer.close();
  81                 } catch (IOException e) {
  82                         stateFile.delete();
  83                         MessagingUtils.error(MementoHelper.class, "Could not save datasource state", e);
  84                         return null;
  85                 }
  86
  87                 // Success !
  88                 return memento;
  89         }
  90 }