why cannot read int value from JTextField

Question

JTextField t1 = new JTextField(" "); String a = t1.getText(); int intA = Integer.parseInt(a); System.out.println(intA); Error java.lang.NumberFormatException: For input string: "1 " 附上我的代码 public class Testing extends JPanel { public int s; public Testing() { JPanel p = new JPanel(); JTextField t1 = new JTextField(" "); JTextField t2 = new JTextField(" "); JTextField t3 = new JTextField(" "); JButton b3 = new JButton("result"); p.add(t1); p.add(t2); p.add(t3); p.add(b3); add(p); b3.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { try { String a = t1.getText(); int intA = Integer.parseInt(a); System.out.println(intA); // String b = t2.getText(); //t3.setText(a+""); } catch (NumberFormatException ignored) { System.out.println(ignored); } } }); } public static void main(String... arg) { Testing p = new Testing(); JFrame frame = new JFrame(); frame.add(p); frame.setLocationRelativeTo(null); frame.pack(); frame.setVisible(true); } }

Answer 1

谢谢@Sjs_k 的答案

把 JTextField t1 = new JTextField(""); 改去 JTextField t1 = new JTextField(5); 就行了