練習：打開，保存文件

/*
練習：打開，保存文件

*/

import java.io.*;
import java.awt.*;
import java.awt.event.*;

class MyMenu {
	private Frame frame;
	private MenuBar menuBar;
	private Menu fileMenu;
	private MenuItem openItem, saveItem, closeItem;
	private FileDialog openDialog, saveDialog;		//對話框
	private TextArea textArea;
	
	private File file;

	MyMenu() {
		init();
	}

	public void init() {
		//設置窗體
		frame = new Frame("my frame");
		frame.setBounds(300, 100, 600, 500);
		//frame.setLayout(new FlowLayout());

		menuBar = new MenuBar();
		fileMenu = new Menu("文件");
		openItem = new MenuItem("打開");
		saveItem = new MenuItem("保存");
		closeItem = new MenuItem("退出");
		textArea = new TextArea();
		//往窗體添加組件
		frame.setMenuBar(menuBar);
		frame.add(textArea);
		menuBar.add(fileMenu);
		fileMenu.add(openItem);
		fileMenu.add(saveItem);
		fileMenu.add(closeItem);
		
		//設置文件對話框
		openDialog = new FileDialog(frame, "打開文件", FileDialog.LOAD);
		saveDialog = new FileDialog(frame, "保存文件", FileDialog.SAVE);

		myEvent();
		frame.setVisible(true);
	}

	private void myEvent() {
		openItem.addActionListener(new ActionListener() {		//打開
			public void actionPerformed(ActionEvent e) {
				openDialog.setVisible(true);
				String dirPath = openDialog.getDirectory();
				String fileName = openDialog.getFile();
				//System.out.println(dirPath + "    " + fileName);
				if(dirPath == null || fileName == null)
					return;
				textArea.setText("");
				file = new File(dirPath, fileName);
				BufferedReader bufr = null;
				try {
					bufr = new BufferedReader(new FileReader(file));
					String str = null;
					while((str = bufr.readLine()) != null)
						textArea.append(str + "\r\n");
				} catch(IOException ie) {
					ie.printStackTrace();
				} finally {
					try {
						if(bufr != null)
							bufr.close();
					} catch(IOException ie) {
						ie.printStackTrace();
					}
				}
			}
		});
		saveItem.addActionListener(new ActionListener() {		//保存
			public void actionPerformed(ActionEvent e) {
				if(file == null) {
					saveDialog.setVisible(true);
					String dirPath = saveDialog.getDirectory();
					String fileName = saveDialog.getFile();
					if(dirPath == null || fileName == null)
						return;
					file = new File(dirPath, fileName);
				}
				BufferedWriter bufw = null;
				try {
					bufw = new BufferedWriter(new FileWriter(file));
					String info = textArea.getText();
					bufw.write(info);
				} catch(IOException ie) {
					ie.printStackTrace();
				} finally {
					try {
						if(bufw != null)
							bufw.close();
					} catch(IOException ie) {
						ie.printStackTrace();
					}
				}
			}
		});
		closeItem.addActionListener(new ActionListener() {		//退出
			public void actionPerformed(ActionEvent e) {
				System.exit(1);
			}
		});
		frame.addWindowListener(new WindowAdapter() {			//關閉窗體
			public void windowClosing(WindowEvent e) {
				System.exit(1);
			}
		});
	}
}
public class OpenAndSaveFile {
	public static void main(String[] args) {
		new MyMenu();
	}
}