Problemas utilizando tree SWT

public static void main(String[] args) {
		final Display display = new Display();
		final Shell shell = new Shell(display);
		shell.setText("ADAGRI");
		RGB color = shell.getBackground().getRGB();
		Label separator1 = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);
		Label locationLb = new Label(shell, SWT.NONE);
		locationLb.setText("Localização: ");
		Composite locationComp = new Composite(shell, SWT.EMBEDDED);
		Label separator2 = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);
		final Composite comp = new Composite(shell, SWT.NONE);
		final Tree fileTree = new Tree(comp, SWT.SINGLE | SWT.BORDER);
		Sash sash = new Sash(comp, SWT.VERTICAL);
		Composite tableComp = new Composite(comp, SWT.EMBEDDED);
		Label separator3 = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);
		Composite statusComp = new Composite(shell, SWT.EMBEDDED);

		java.awt.Frame locationFrame = SWT_AWT.new_Frame(locationComp);
		final java.awt.TextField locationText = new java.awt.TextField();
		locationFrame.add(locationText);

		java.awt.Frame statusFrame = SWT_AWT.new_Frame(statusComp);
		statusFrame.setBackground(new java.awt.Color(color.red, color.green,
				color.blue));
		final java.awt.Label statusLabel = new java.awt.Label();
		statusFrame.add(statusLabel);
		statusLabel.setText("ADAGRI");

sash.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				if (e.detail == SWT.DRAG)
					return;
				GridData data = (GridData) fileTree.getLayoutData();
				Rectangle trim = fileTree.computeTrim(0, 0, 0, 0);
				data.widthHint = e.x - trim.width;
				comp.layout();
			}
		});

		File[] roots = File.listRoots();
		for (int i = 0; i < roots.length; i++) {
			File file = roots[i];
			TreeItem treeItem = new TreeItem(fileTree, SWT.NONE);
			treeItem.setText(file.getAbsolutePath());
			treeItem.setData(file);
			new TreeItem(treeItem, SWT.NONE);
		}
		fileTree.addListener(SWT.Expand, new Listener() {
			public void handleEvent(Event e) {
				TreeItem item = (TreeItem) e.item;
				if (item == null)
					return;
				if (item.getItemCount() == 1) {
					TreeItem firstItem = item.getItems()[0];
					if (firstItem.getData() != null)
						return;
					firstItem.dispose();
				} else {
					return;
				}
				File root = (File) item.getData();
				File[] files = root.listFiles();
				if (files == null)
					return;
				for (int i = 0; i < files.length; i++) {
					File file = files[i];
					if (file.isDirectory()) {
						TreeItem treeItem = new TreeItem(item, SWT.NONE);
						treeItem.setText(file.getName());
						treeItem.setData(file);
						new TreeItem(treeItem, SWT.NONE);
					}
				}
			}
		});

		fileTree.addListener(SWT.MouseDoubleClick, new Listener() {
			public void handleEvent(Event e) {
				TreeItem item = (TreeItem) e.item;

				System.out.println(item.getData());
				
				if (item == null){
						return;
				}
				final File root = (File) item.getData();

				for (File file : root.listFiles()) {

					if (file.getName().endsWith(".tif")) {
						System.out.println(root.getName());

					}

				}
			}
		});

		fileTree.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				TreeItem item = (TreeItem) e.item;
				
				if (item == null)
					return;
				
				final File root = (File) item.getData();
				statusLabel.setText(root.getAbsolutePath());
				locationText.setText(root.getAbsolutePath());
			}
		});

		GridLayout layout = new GridLayout(4, false);

		layout.marginWidth = layout.marginHeight = 0;
		layout.horizontalSpacing = layout.verticalSpacing = 1;
		shell.setLayout(layout);
		GridData data;
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 4;
		separator1.setLayoutData(data);
		data = new GridData();
		data.horizontalSpan = 1;
		data.horizontalIndent = 10;
		locationLb.setLayoutData(data);
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 2;
		data.heightHint = locationText.getPreferredSize().height;
		locationComp.setLayoutData(data);
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 1;
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 4;
		separator2.setLayoutData(data);
		data = new GridData(GridData.FILL_BOTH);
		data.horizontalSpan = 4;
		comp.setLayoutData(data);
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 4;
		separator3.setLayoutData(data);
		data = new GridData(GridData.FILL_HORIZONTAL);
		data.horizontalSpan = 4;
		data.heightHint = statusLabel.getPreferredSize().height;
		statusComp.setLayoutData(data);

		layout = new GridLayout(3, false);
		layout.marginWidth = layout.marginHeight = 0;
		layout.horizontalSpacing = layout.verticalSpacing = 1;
		comp.setLayout(layout);
		data = new GridData(GridData.FILL_VERTICAL);
		data.widthHint = 200;
		fileTree.setLayoutData(data);
		data = new GridData(GridData.FILL_VERTICAL);
		sash.setLayoutData(data);
		data = new GridData(GridData.FILL_BOTH);
		tableComp.setLayoutData(data);

		shell.open();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch())
				display.sleep();
		}
		display.dispose();
	}
}