Someone

public static class SaveAction extends AbstractAction
	{
		/**
		 * 
		 */
		protected boolean showDialog;

		/**
		 * 
		 */
		protected String lastDir = null;

		/**
		 * 
		 */
		public SaveAction(boolean showDialog)
		{
			this.showDialog = showDialog;
		}

		/**
		 * Saves XML+PNG format.
		 */
		protected void saveXmlPng(BasicGraphEditor editor, String filename,
				Color bg) throws IOException
		{
			mxGraphComponent graphComponent = editor.getGraphComponent();
			mxGraph graph = graphComponent.getGraph();

			// Creates the image for the PNG file
			BufferedImage image = mxCellRenderer.createBufferedImage(graph,
					null, 1, bg, graphComponent.isAntiAlias(), null,
					graphComponent.getCanvas());

			// Creates the URL-encoded XML data
			mxCodec codec = new mxCodec();
			String xml = URLEncoder.encode(
					mxUtils.getXml(codec.encode(graph.getModel())), "UTF-8");
			mxPngEncodeParam param = mxPngEncodeParam
					.getDefaultEncodeParam(image);
			param.setCompressedText(new String[] { "mxGraphModel", xml });

			// Saves as a PNG file
			FileOutputStream outputStream = new FileOutputStream(new File(
					filename));
			try
			{
				mxPngImageEncoder encoder = new mxPngImageEncoder(outputStream,
						param);

				if (image != null)
				{
					encoder.encode(image);

					editor.setModified(false);
					editor.setCurrentFile(new File(filename));
				}
				else
				{
					JOptionPane.showMessageDialog(graphComponent,
							mxResources.get("noImageData"));
				}
			}
			finally
			{
				outputStream.close();
			}
		}

		/**
		 * 
		 */
		public void actionPerformed(ActionEvent e)
		{
			BasicGraphEditor editor = getEditor(e);

			if (editor != null)
			{
				mxGraphComponent graphComponent = editor.getGraphComponent();
				mxGraph graph = graphComponent.getGraph();
				FileFilter selectedFilter = null;
				DefaultFileFilter xmlPngFilter = new DefaultFileFilter(".png",
						"PNG+XML " + mxResources.get("file") + " (.png)");
				FileFilter vmlFileFilter = new DefaultFileFilter(".html",
						"VML " + mxResources.get("file") + " (.html)");
				String filename = null;
				boolean dialogShown = false;

				if (showDialog || editor.getCurrentFile() == null)
				{
					String wd;

					if (lastDir != null)
					{
						wd = lastDir;
					}
					else if (editor.getCurrentFile() != null)
					{
						wd = editor.getCurrentFile().getParent();
					}
					else
					{
						wd = System.getProperty("user.dir");
					}

					JFileChooser fc = new JFileChooser(wd);

					// Adds the default file format
					FileFilter defaultFilter = xmlPngFilter;
					fc.addChoosableFileFilter(defaultFilter);

					// Adds special vector graphics formats and HTML
					fc.addChoosableFileFilter(new DefaultFileFilter(".mxe",
							"mxGraph Editor " + mxResources.get("file")
									+ " (.mxe)"));
					fc.addChoosableFileFilter(new DefaultFileFilter(".txt",
							"Graph Drawing " + mxResources.get("file")
									+ " (.txt)"));
					fc.addChoosableFileFilter(new DefaultFileFilter(".svg",
							"SVG " + mxResources.get("file") + " (.svg)"));
					fc.addChoosableFileFilter(vmlFileFilter);
					fc.addChoosableFileFilter(new DefaultFileFilter(".html",
							"HTML " + mxResources.get("file") + " (.html)"));

					// Adds a filter for each supported image format
					Object[] imageFormats = ImageIO.getReaderFormatNames();

					// Finds all distinct extensions
					HashSet<String> formats = new HashSet<String>();

					for (int i = 0; i < imageFormats.length; i++)
					{
						String ext = imageFormats[i].toString().toLowerCase();
						formats.add(ext);
					}

					imageFormats = formats.toArray();

					for (int i = 0; i < imageFormats.length; i++)
					{
						String ext = imageFormats[i].toString();
						fc.addChoosableFileFilter(new DefaultFileFilter("."
								+ ext, ext.toUpperCase() + " "
								+ mxResources.get("file") + " (." + ext + ")"));
					}

					// Adds filter that accepts all supported image formats
					fc.addChoosableFileFilter(new DefaultFileFilter.ImageFileFilter(
							mxResources.get("allImages")));
					fc.setFileFilter(defaultFilter);
					int rc = fc.showDialog(null, mxResources.get("save"));
					dialogShown = true;

					if (rc != JFileChooser.APPROVE_OPTION)
					{
						return;
					}
					else
					{
						lastDir = fc.getSelectedFile().getParent();
					}

					filename = fc.getSelectedFile().getAbsolutePath();
					selectedFilter = fc.getFileFilter();

					if (selectedFilter instanceof DefaultFileFilter)
					{
						String ext = ((DefaultFileFilter) selectedFilter)
								.getExtension();

						if (!filename.toLowerCase().endsWith(ext))
						{
							filename += ext;
						}
					}

					if (new File(filename).exists()
							&& JOptionPane.showConfirmDialog(graphComponent,
									mxResources.get("overwriteExistingFile")) != JOptionPane.YES_OPTION)
					{
						return;
					}
				}
				else
				{
					filename = editor.getCurrentFile().getAbsolutePath();
				}

				try
				{
					String ext = filename
							.substring(filename.lastIndexOf('.') + 1);

					if (ext.equalsIgnoreCase("svg"))
					{
						mxSvgCanvas canvas = (mxSvgCanvas) mxCellRenderer
								.drawCells(graph, null, 1, null,
										new CanvasFactory()
										{
											public mxICanvas createCanvas(
													int width, int height)
											{
												mxSvgCanvas canvas = new mxSvgCanvas(
														mxUtils.createSvgDocument(
																width, height));
												canvas.setEmbedded(true);

												return canvas;
											}

										});

						mxUtils.writeFile(mxUtils.getXml(canvas.getDocument()),
								filename);
					}
					else if (selectedFilter == vmlFileFilter)
					{
						mxUtils.writeFile(mxUtils.getXml(mxCellRenderer
								.createVmlDocument(graph, null, 1, null, null)
								.getDocumentElement()), filename);
					}
					else if (ext.equalsIgnoreCase("html"))
					{
						mxUtils.writeFile(mxUtils.getXml(mxCellRenderer
								.createHtmlDocument(graph, null, 1, null, null)
								.getDocumentElement()), filename);
					}
					else if (ext.equalsIgnoreCase("mxe")
							|| ext.equalsIgnoreCase("xml"))
					{
						mxCodec codec = new mxCodec();
						String xml = mxUtils.getXml(codec.encode(graph
								.getModel()));

						mxUtils.writeFile(xml, filename);

						editor.setModified(false);
						editor.setCurrentFile(new File(filename));
					}
					else if (ext.equalsIgnoreCase("txt"))
					{
						String content = mxGdCodec.encode(graph)
								.getDocumentString();

						mxUtils.writeFile(content, filename);
					}
					else
					{
						Color bg = null;

						if ((!ext.equalsIgnoreCase("gif") && !ext
								.equalsIgnoreCase("png"))
								|| JOptionPane.showConfirmDialog(
										graphComponent, mxResources
												.get("transparentBackground")) != JOptionPane.YES_OPTION)
						{
							bg = graphComponent.getBackground();
						}

						if (selectedFilter == xmlPngFilter
								|| (editor.getCurrentFile() != null
										&& ext.equalsIgnoreCase("png") && !dialogShown))
						{
							saveXmlPng(editor, filename, bg);
						}
						else
						{
							BufferedImage image = mxCellRenderer
									.createBufferedImage(graph, null, 1, bg,
											graphComponent.isAntiAlias(), null,
											graphComponent.getCanvas());

							if (image != null)
							{
								ImageIO.write(image, ext, new File(filename));
							}
							else
							{
								JOptionPane.showMessageDialog(graphComponent,
										mxResources.get("noImageData"));
							}
						}
					}
				}
				catch (Throwable ex)
				{
					ex.printStackTrace();
					JOptionPane.showMessageDialog(graphComponent,
							ex.toString(), mxResources.get("error"),
							JOptionPane.ERROR_MESSAGE);
				}
			}
		}
	}