import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.File; import java.io.IOException; import java.io.RandomAccessFile; class xs extends JFrame implements ActionListener { File f1=new File("学生管理系统"); JButton an1=new JButton("录入"); JButton an2=new JButton("显示"); JTextField name=new JTextField(8); JTextField sno=new JTextField(8); JTextArea txt=new JTextArea(5,30); JPanel p1=new JPanel(); JPanel p2=new JPanel(); xs() { setTitle("学生管理系统"); setVisible(true); setBounds(100,50,400,250); setDefaultCloseOperation(EXIT_ON_CLOSE); add(p1,"North"); p1.setBackground(Color.cyan); p1.add(new JLabel("输入姓名")); p1.add(name); p1.add(new JLabel("输入学号")); p1.add(sno); p1.add(an1); an1.addActionListener(this); add(p2,"Center"); p2.add(an2); p2.add(txt); an2.addActionListener(this); validate(); } public void actionPerformed(ActionEvent e) { if (e.getSource()==an1) { sr(); } if (e.getSource()==an2) { sc(); } } public void sc() { int number = 1; try { RandomAccessFile infile = new RandomAccessFile(f1, "r"); String 学生 = null; while ((学生 = infile.readUTF()) != null) { txt.append("\n" + number + " " + 学生); txt.append(" " + infile.readUTF()); txt.append("\n--------------------"); number++; } infile.close(); } catch (Exception ee) {} } public void sr() { try{ RandomAccessFile outfile=new RandomAccessFile(f1,"rw"); if (f1.exists()) { long length=f1.length(); outfile.seek(length); } outfile.writeUTF("姓名："+name.getText());当录入按钮按下只能保存当前输入数据并按下显示按钮显示出来