Swing Java Tutorial

public JComboBox()
JComboBox comboBox = new JComboBox();
public JComboBox(Object listData[])
String labels[] = { "A", "B", "C", "D", "E"};
JComboBox comboBox = new JComboBox(labels);
public JComboBox(Vector listData)
Vector vector = aBufferedImage.getSources();
JComboBox comboBox = new JComboBox(vector);
public JComboBox(ComboBoxModel model)
ResultSet results = aJDBCStatement.executeQuery("SELECT columnName FROM tableName");
DefaultComboBoxModel model = new DefaultComboBoxModel();
while (result.next())
  model.addElement(results.getString(1));
JComboBox comboBox = new JComboBox(model);

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JComboBox;
import javax.swing.JFrame;
public class Main extends JFrame {
  JComboBox combo = new JComboBox();
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    combo.addItem("A");
    combo.addItem("H");
    combo.addItem("P");
    combo.setEditable(true);
    System.out.println("#items=" + combo.getItemCount());
    combo.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Selected index=" + combo.getSelectedIndex()
            + " Selected item=" + combo.getSelectedItem());
      }
    });
    getContentPane().add(combo);
    pack();
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}