由于Java_3.java 文件不完整，请在注释行//*********Found********** 下一行语句的下划线地方填写入正确内容，然后删除下划线，请勿对其他内容进行改动

//打印无符号整数位 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class Java_3 extends JFrame {
    public Java_3() {
        super("打印无符号整数位");
        Container c = getContentPane();
        c.setLayout(new FlowLayout());
        c.add(new JLabel("请输入整数: "));
        final JTextField output = new JTextField(33);
        JTextField input = new JTextField(10);
        input.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent e) {
                        int val = Integer.parseInt(
                                e.getActionCommand());
                        output.setText(getBits(val));
                    }
                });
        c.add(input);
        c.add(new JLabel("该数的二进制位表示是"));
        output.setEditable(false);
        //*********Found******** 
        c.add(_________________);
        setSize(720, 70);
        show();
    }
 
    private String getBits(int value) {
        int displayMask = 1 << 31;
        StringBuffer buf = new StringBuffer(35);
        for (int c = 1; c <= 32; c++) {
            buf.append(
                    (value & displayMask) == 0 ? '0' : '1');
            value <<= 1;
            if (c % 8 == 0) {
                buf.append(' ');
            }
        }
        return buf.toString();
    }
 
    public static void main(String args[]) {
        Java_3 app = new Java_3();
        app.addWindowListener(
                new WindowAdapter() {
                    //*********Found******** 
                    public void windowClosing(___________ e) {
                        System.exit(0);
                    }
                });
    }
}