java JComboBox 自动查找

package util;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.List;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import java.util.Collections;
import java.util.Arrays;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JOptionPane;

/**
 * @author SamZheng
 * 带有自动检查功能的CombBox
 */
public class JAutoCompleteComboBox
    extends JComboBox {
  private AutoCompleter completer;

  public JAutoCompleteComboBox() {
    super();
    addCompleter();
  }

  public JAutoCompleteComboBox(ComboBoxModel cm) {
    super(cm);
    addCompleter();
  }

  public JAutoCompleteComboBox(Object[] items) {
    super(items);
    addCompleter();
  }

  public JAutoCompleteComboBox(List v) {
    super( (Vector) v);
    addCompleter();
  }

  private void addCompleter() {
    setEditable(true);
    completer = new AutoCompleter(this);
  }

  public void autoComplete(String str) {
    this.completer.autoComplete(str, str.length());
  }

  public String getText() {
    return ( (JTextField) getEditor().getEditorComponent()).getText();
  }

  public void setText(String text) {
    ( (JTextField) getEditor().getEditorComponent()).setText(text);
  }

  public boolean containsItem(String itemString) {
    for (int i = 0; i < this.getModel().getSize(); i++) {
      String _item = "" + this.getModel().getElementAt(i);
      if (_item.equals(itemString)) {
        return true;
      }
    }
    return false;
  }

  /*
   * 测试方法
   */
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    Object[] items = new Object[] {
        "zzz","zba","aab","abc", "aab","dfg","aba", "hpp", "pp", "hlp"};
    //排序内容
    //java.util.ArrayList list = new java.util.ArrayList(Arrays.asList(items));
    //Collections.sort(list);
    //JComboBox cmb = new JAutoCompleteComboBox(list.toArray());
    Arrays.sort(items);
    JComboBox cmb = new JAutoCompleteComboBox(items);
    cmb.setSelectedIndex(-1);
    frame.getContentPane().add(cmb);
    frame.setSize(400, 80);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}

/**
 *   自动完成器。自动找到最匹配的项目，并排在列表的最前面。
 *   @author   SamZheng
 */

class AutoCompleter
    implements KeyListener, ItemListener {

  private JComboBox owner = null;
  private JTextField editor = null;

  private ComboBoxModel model = null;

  public AutoCompleter(JComboBox comboBox) {
    owner = comboBox;
    editor = (JTextField) comboBox.getEditor().getEditorComponent();
    editor.addKeyListener(this);
    model = comboBox.getModel();
    owner.addItemListener(this);
  }

  public void keyTyped(KeyEvent e) {}

  public void keyPressed(KeyEvent e) {}

  public void keyReleased(KeyEvent e) {
    char ch = e.getKeyChar();
    if (ch == KeyEvent.CHAR_UNDEFINED || Character.isISOControl(ch) ||
        ch == KeyEvent.VK_DELETE) {
      return;
    }

    int caretPosition = editor.getCaretPosition();
    String str = editor.getText();
    if (str.length() == 0) {
      return;
    }
    autoComplete(str, caretPosition);
  }

  /**
   *   自动完成。根据输入的内容，在列表中找到相似的项目.
   */
  protected void autoComplete(String strf, int caretPosition) {
    Object[] opts;
    opts = getMatchingOptions(strf.substring(0, caretPosition));
    if (owner != null) {
      model = new DefaultComboBoxModel(opts);
      owner.setModel(model);
    }
    if (opts.length > 0) {
      String str = opts[0].toString();
      if(caretPosition>editor.getText().length()) return;
      editor.setCaretPosition(caretPosition);
      editor.setText(editor.getText().trim().substring(0,caretPosition));
      if (owner != null) {
        try {
          owner.showPopup();
        }
        catch (Exception ex) {
          ex.printStackTrace();
        }
      }
    }
  }

  /**
   *
   *   找到相似的项目,   并且将之排列到数组的最前面。
   *   @param   str
   *   @return   返回所有项目的列表。
   */
  protected Object[] getMatchingOptions(String str) {
    List v = new Vector();
    List v1 = new Vector();

    for (int k = 0; k < model.getSize(); k++) {
      Object itemObj = model.getElementAt(k);
      if (itemObj != null) {
        String item = itemObj.toString().toLowerCase();
        if (item.startsWith(str.toLowerCase())) {
          v.add(model.getElementAt(k));
        }
        else {
          v1.add(model.getElementAt(k));
        }
      }
      else {
        v1.add(model.getElementAt(k));
      }
    }
    for (int i = 0; i < v1.size(); i++) {
      v.add(v1.get(i));
    }
    if (v.isEmpty()) {
      v.add(str);
    }
    return v.toArray();
  }

  public void itemStateChanged(ItemEvent event) {
    if (event.getStateChange() == ItemEvent.SELECTED) {
      int caretPosition = editor.getCaretPosition();
      if (caretPosition != -1) {
        try {
          editor.moveCaretPosition(caretPosition);
        }
        catch (IllegalArgumentException ex) {
          ex.printStackTrace();
        }
      }
    }
  }
}