FileReader和FileWriter
public class Ftest extends JFrame{ private static final long sertalVersionUID = 1L; private JPanel jContentPane = null; private JTextArea jTextArea = null; private JPanel controlPane = null; private JButton openButton = null; private JButton closeButton = null; private JTextArea geJTextArea(){ if(jTextArea == null){ jTextArea = new JTextArea(); } return jTextArea; } private JPanel getControlPanel(){ if(controlPane == null){ controlPane = new JPanel(); controlPane.setLayout(new FlowLayout()); controlPane.add(getOpenButton(),null); controlPane.add(getCloseButton(),null); } return controlPane; } private JButton getOpenButton() { if(openButton == null){ openButton = new JButton(); openButton.setText("写入文件"); openButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub File file = new File("word.txt"); try { FileWriter out = new FileWriter(file); String s = jTextArea.getText(); out.write(s); out.close(); } catch (Exception e1) { // TODO: handle exception e1.printStackTrace(); } } }); } return openButton; } private JButton getCloseButton(){ if(closeButton == null){ closeButton = new JButton(); closeButton.setText("读取文件"); closeButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub File file = new File("word.txt"); try { FileReader in = new FileReader(file); char byt[] = new char[1024]; int len = in.read(byt); jTextArea.setText(new String(byt,0,len)); in.close(); } catch (Exception e1) { // TODO: handle exception e1.printStackTrace(); } } }); } return closeButton; } private void initialize(){ 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(geJTextArea(),BorderLayout.CENTER); jContentPane.add(getControlPanel(), BorderLayout.SOUTH); } return jContentPane; } public Ftest(){ super(); initialize(); } public static void main(String[] args) { // TODO Auto-generated method stub Ftest thisClass = new Ftest(); thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); thisClass.setVisible(true); } }