Java Swing How to - Make JFileChooser open in the current directory the user is in

Question

We would like to know how to make JFileChooser open in the current directory the user is in.
Answer

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.io.File;
import java.io.FileReader;
//from  w  ww .  j a  v  a2  s  .  co m
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JToolBar;
import javax.swing.border.EmptyBorder;

public class Main {
  JPanel gui = new JPanel(new BorderLayout());
  JFileChooser fileChooser;
  private JTextArea output = new JTextArea(10, 40);

  Main() {
    gui.setBorder(new EmptyBorder(2, 3, 2, 3));

    String userDirLocation = System.getProperty("user.dir");
    File userDir = new File(userDirLocation);
    // default to user directory
    fileChooser = new JFileChooser(userDir);

    Action open = new AbstractAction("Open") {
      @Override
      public void actionPerformed(ActionEvent e) {
        int result = fileChooser.showOpenDialog(gui);
        if (result == JFileChooser.APPROVE_OPTION) {
          try {
            File f = fileChooser.getSelectedFile();
            FileReader fr = new FileReader(f);
            output.read(fr, f);
            fr.close();
          } catch (Exception ex) {
            ex.printStackTrace();
          }
        }
      }
    };

    Action save = new AbstractAction("Save") {
      @Override
      public void actionPerformed(ActionEvent e) {
        int result = fileChooser.showSaveDialog(gui);
        System.out.println("Not supported yet.");
      }
    };

    JToolBar tb = new JToolBar();
    gui.add(tb, BorderLayout.PAGE_START);
    tb.add(open);
    tb.add(save);

    gui.add(new JScrollPane(output));
  }

  public JComponent getGui() {
    return gui;
  }

  public static void main(String[] args) {
    Main cicd = new Main();
    JFrame f = new JFrame("Chooser In Current Dir");
    f.add(cicd.getGui());
    f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    f.pack();
    f.setVisible(true);
  }
}