Java——文件选择框：JFileChooser

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Scanner;

import javax.imageio.stream.FileImageInputStream;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

//=================================================
// File Name       :	JFileChooser_demo
//------------------------------------------------------------------------------
// Author          :	Common

//类名：myWindowEventHandle
//属性：
//方法：
class Note implements ActionListener{

	private JFrame frame = new JFrame("窗体");					//定义窗体
	private JTextArea area = new JTextArea("JTextArea");	//定义文本区
	private JButton open = new JButton("打开文件");			//打开文件
	private JButton save = new JButton("保存文件");			//保存文件
	private JLabel label = new JLabel("现在没有打开的文件");

	private JPanel butpan = new JPanel();

	public Note(){
		this.butpan.add(open);
		this.butpan.add(save);
		//设置窗体中的布局管理器为BorderLayout，所有的组件水平和垂直间距为3
		frame.setLayout(new BorderLayout(3,3));
		frame.add(this.label,BorderLayout.NORTH);
		frame.add(this.butpan,BorderLayout.SOUTH);
		frame.add(this.area, BorderLayout.CENTER);
		this.frame.setSize(330,180);
		this.frame.setVisible(true);
		this.frame.addWindowListener(new WindowAdapter(){	//加入事件监听
			public void windowClosing(WindowEvent arg0) {			//窗口关闭时触发，按下关闭按钮
			// TODO 自动生成的方法存根
			System.out.println("windowClosing-->窗口关闭");
			System.exit(1);
			}
		});
		this.open.addActionListener(this);
		this.save.addActionListener(this);
//		this.frame.setSize(330,180);
//		this.frame.setVisible(true);
	}

	@Override
	public void actionPerformed(ActionEvent e) {	//按键事件监听
		// TODO 自动生成的方法存根
		File file = null;
		int result = 0;
		JFileChooser fileChooser = new JFileChooser();
		if(e.getSource() == this.open){
			this.area.setText("");
			fileChooser.setApproveButtonText("确定");		//定义“确定“按钮”
			fileChooser.setDialogTitle("打开文件");				//定义文件选择框标题
			result = fileChooser.showOpenDialog(this.frame);		//显示打开对话框
			if(result == JFileChooser.APPROVE_OPTION){
				file = fileChooser.getSelectedFile();
				this.label.setText("打开的文件名称为："+file.getName());
			}else if(result == JFileChooser.CANCEL_OPTION){
				this.label.setText("没有选择任何文件");
			}else{
				this.label.setText("操作出现错误");
			}
			if(file != null){
				try{
					Scanner scan = new Scanner(new FileInputStream(file));//设置输入流
					scan.useDelimiter("\n");						//设置换行为分隔符
					while(scan.hasNext()){							//循环读取
						this.area.append(scan.next());		//读取内容到文本区
						this.area.append("\n");					//设置换行
					}
					scan.close();												//关闭
				}catch(Exception ex){
					this.label.setText("文件读取出错");
				}
			}
		}

		if(e.getSource() == this.save){

			result = fileChooser.showSaveDialog(this.frame);		//显示保存文件框
			if(result == JFileChooser.APPROVE_OPTION){
				file = fileChooser.getSelectedFile();
				this.label.setText("存储的文件名称为："+file.getName());
			}else if(result == JFileChooser.CANCEL_OPTION){
				this.label.setText("没有选择任何文件");
			}else{
				this.label.setText("操作出现错误");
			}
			if(file != null){
				try{
					PrintStream out = new PrintStream(new FileOutputStream(file));
					out.print(this.area.getText());
					out.close();
				}catch(Exception ex){
					this.label.setText("文件保存出错");
				}
			}
		}

	}

}

//主类
//Function        : 	JFileChooser_demo
public class JFileChooser_demo {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		new Note();

	}

}