How to print selected items in a SWT tree

[Java Tip]

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class Snippet61 {

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
    for (int i = 0; i < 4; i++) {
      TreeItem item0 = new TreeItem(tree, 0);
      item0.setText("Item " + i);
      for (int j = 0; j < 4; j++) {
        TreeItem item1 = new TreeItem(item0, 0);
        item1.setText("SubItem " + i + " " + j);
        for (int k = 0; k < 4; k++) {
          TreeItem item2 = new TreeItem(item1, 0);
          item2.setText("SubItem " + i + " " + j + " " + k);
        }
      }
    }
    tree.setBounds(0, 0, 100, 100);
    tree.addListener(SWT.Selection, new Listener() {
      public void handleEvent(Event e) {
        String string = "";
        TreeItem[] selection = tree.getSelection();
        for (int i = 0; i < selection.length; i++)
          string += selection[i] + " ";
        System.out.println("Selection={" + string + "}");
      }
    });
    tree.addListener(SWT.DefaultSelection, new Listener() {
      public void handleEvent(Event e) {
        String string = "";
        TreeItem[] selection = tree.getSelection();
        for (int i = 0; i < selection.length; i++)
          string += selection[i] + " ";
        System.out.println("DefaultSelection={" + string + "}");
      }
    });
    tree.addListener(SWT.Expand, new Listener() {
      public void handleEvent(Event e) {
        System.out.println("Expand={" + e.item + "}");
      }
    });
    tree.addListener(SWT.Collapse, new Listener() {
      public void handleEvent(Event e) {
        System.out.println("Collapse={" + e.item + "}");
      }
    });
    tree.getItems()[0].setExpanded(true);
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}