File file = new File("d:/1.txt");

public class FileTest{
	public static void main(String[]args){
		File file = new File("world.txt");
		try{
			FileOutputStream out = new FileOutputStream(file);
			byte buy[] = "我有一頭小毛驢，我從來也不騎。".getBytes();
			out.write(buy);
			out.close();
		} catch(Exception e) {
			e.printStackTrace();
		}
		try{
			//創(chuàng)建FileInputStream類對(duì)象
			FileInputStream in = new FileInputStream(file);
			byte byt[] = new byte[1024]; //創(chuàng)建byte數(shù)組
			int len = in.read(byt); //從文件中讀取信息
			System.out.println("文件中的信息是：" + new String(byt, 0, len))
			in.close();
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
}

public class Ftest extends JFrame{
	private static final long serialVersionUID = 1L;
	private JPanel jContentPane = null; //創(chuàng)建面板對(duì)象
	private JTextArea jTextArea = null; //創(chuàng)建文本域?qū)ο?
	private JPanel controlPanel = null; //創(chuàng)建面板對(duì)象
	private JButton openButton = null; //創(chuàng)建按鈕對(duì)象
	private JButton closeButton = null; //創(chuàng)建按鈕對(duì)象
	private JButton getOpenButton(){
		if(openButton == null){
			openButton = new JButton();
			openButton.setText("寫入文件"); //修改按鈕的提示信息
			openButton.addActionListener(new ActionListener(){
				//按鈕的單機(jī)事件
				public void actionPerformed(ActionEvent e){
					File file = new File("world.txt"); //創(chuàng)建文件對(duì)象
					try{
						FileWriter out = new FileWriter(file); //創(chuàng)建FileWriter對(duì)象
						String s = jTextArea.getText(); //獲取文本域中文本
						out.write(s); //將信息寫入磁盤文件
						out.close(); //將流關(guān)閉
					catch(Exception e1){
						e1.printStackTrace();
					}
				}
			});
		}
		return openButton;
	}
	private JButton getCloseButton(){
		if(closeButton == null){
			closeButton = new JButton();
			closeButton.setText("讀取文件"); //修改按鈕的提示信息
			closeButton.addActionListener(new ActionListener(){
				//按鈕的單擊事件
				public void actionPerformed(ActionEvent e){
					File file = new File("world.txt"); //創(chuàng)建文件對(duì)象
					try{
						FileReader in = new FileReader(file); //創(chuàng)建FileReader對(duì)象
						char byt[] = new char[1024]; //創(chuàng)建char型數(shù)組
						int len = in.read(byt); //將字節(jié)讀入數(shù)組
						jTextArea.setText(new String(byt, 0, len)); //設(shè)置文本域的顯示信息
						in.close(); //關(guān)閉流
					}catch(Exception e1){
						e1.printStackTrace();
					}
				}
			});
		}
		return closeButton;
	}
	public Ftest(){
		super();
		initialize();
	}
	private void initilize(){
		this.setSize(300,200);
		this.setContentPane(getJContentPane());
		this.setTitle("JFrame");
	}
	private JPanel getJContentPane(){
		if(jContentPane == null){
			jContentPane = new JPanel();
			jContentPane.setLayout(new BorderLayout());
			jContentPane.add(getJTextArea(), BorderLayout.CENTER);
			jContentPane.add(getControlPanel(),BorderLayout.SOUTH);
		}
		return jContentPane;
	}
	public static void main(String[] args){ //主方法
		Ftest thisClass = new Ftest(); //創(chuàng)建本類對(duì)象
		thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		thisClass.setVisible(true); //設(shè)置該窗體的顯示狀態(tài)
	}
}