Java获取新建文件时文件后缀名

  使用JChooser获取新建文件时文件后缀名：

 

/**
 * @author Henry
 * @create 2009-9-30
 */
package com.cn.dom4j;

/**
 * @author Henry
 *
 */
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.JFrame;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.filechooser.FileNameExtensionFilter;

/**
 * @author Henry
 *
 */
public class DomViewerFrame extends JFrame
{
	private static final int DEFAULT_WIDTH = 300;
	private static final int DEFAULT_HIGHT = 400;
	private JLabel label;
	private JFileChooser chooser;

	public DomViewerFrame()
	{
		setTitle("XMLHandler");
		setSize(DEFAULT_WIDTH, DEFAULT_HIGHT);

		label = new JLabel();
		add(label);

		chooser = new JFileChooser();
		chooser.setCurrentDirectory(new File("C:\\"));
		FileNameExtensionFilter filter = new FileNameExtensionFilter("*.xml","xml","xfdl");
		chooser.setFileFilter(filter);
		
		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);

		JMenu menu = new JMenu("File");
		menuBar.add(menu);
		
		JMenuItem saveItem = new JMenuItem("Save");
		menu.add(saveItem);
		saveItem.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
				int result = chooser.showSaveDialog(null);
				if (result == JFileChooser.OPEN_DIALOG)
				{
					StringBuffer name = new StringBuffer(chooser.getSelectedFile().getPath());
					name.append("."+((FileNameExtensionFilter)chooser.getFileFilter()).getExtensions()[0]);//取得选取文件后缀
					label.setText(name.toString());
					
					Dom4j.createXML(name.toString());
				}
				if(result == JFileChooser.CANCEL_OPTION)
				{
					System.out.println("You pressed cancel");
					label.setText("You pressed cancel");
				}
			}
		});
		
		JMenuItem openItem = new JMenuItem("Open");
		menu.add(openItem);
		openItem.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				int result = chooser.showOpenDialog(null);
				if (result == JFileChooser.APPROVE_OPTION)
				{
					String name = chooser.getSelectedFile().getPath();
					label.setText(name);
				}
			}
		});
		
		JMenuItem exitItem = new JMenuItem("Exit");
		menu.add(exitItem);
		exitItem.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				System.exit(0);
			}
		});
	}
}