让JComboBox有自动查找和完成功能

转载：http://lyx262.iteye.com/blog/766792

package cn.edu.cuit.isi.benzeph;

import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Arrays;
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;

/**
 * @author SamZheng 带有自动检查功能的CombBox
 */

@SuppressWarnings("unchecked")
public class JAutoCompleteComboBox extends JComboBox {

	private static final long serialVersionUID = 1L;
	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
 */

@SuppressWarnings("unchecked")
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();
				}
			}
		}
	}
}