布局管理器，将一个十进制整数分别转换成二进制、八进制和十六进制整数

下面是一个使用Java Swing的布局管理器实现将一个十进制整数分别转换成二进制、八进制和十六进制整数的GUI程序：

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class NumberConverter extends JFrame implements ActionListener {

    private static final long serialVersionUID = 1L;
    private static final int WIDTH = 400;
    private static final int HEIGHT = 150;
    private static final String TITLE = "Number Converter";

    private JTextField decimalField, binaryField, octalField, hexadecimalField;

    public NumberConverter() {
        super(TITLE);
        setSize(WIDTH, HEIGHT);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));

        JPanel decimalPanel = new JPanel(new BorderLayout());
        JLabel decimalLabel = new JLabel("Decimal:");
        decimalField = new JTextField();
        decimalField.setPreferredSize(new Dimension(200, 25));
        decimalPanel.add(decimalLabel, BorderLayout.WEST);
        decimalPanel.add(decimalField, BorderLayout.CENTER);
        mainPanel.add(decimalPanel);

        JPanel binaryPanel = new JPanel(new BorderLayout());
        JLabel binaryLabel = new JLabel("Binary:");
        binaryField = new JTextField();
        binaryField.setPreferredSize(new Dimension(200, 25));
        binaryField.setEditable(false);
        binaryPanel.add(binaryLabel, BorderLayout.WEST);
        binaryPanel.add(binaryField, BorderLayout.CENTER);
        mainPanel.add(binaryPanel);

        JPanel octalPanel = new JPanel(new BorderLayout());
        JLabel octalLabel = new JLabel("Octal:");
        octalField = new JTextField();
        octalField.setPreferredSize(new Dimension(200, 25));
        octalField.setEditable(false);
        octalPanel.add(octalLabel, BorderLayout.WEST);
        octalPanel.add(octalField, BorderLayout.CENTER);
        mainPanel.add(octalPanel);

        JPanel hexadecimalPanel = new JPanel(new BorderLayout());
        JLabel hexadecimalLabel = new JLabel("Hexadecimal:");
        hexadecimalField = new JTextField();
        hexadecimalField.setPreferredSize(new Dimension(200, 25));
        hexadecimalField.setEditable(false);
        hexadecimalPanel.add(hexadecimalLabel, BorderLayout.WEST);
        hexadecimalPanel.add(hexadecimalField, BorderLayout.CENTER);
        mainPanel.add(hexadecimalPanel);

        JPanel buttonPanel = new JPanel();
        JButton convertButton = new JButton("Convert");
        convertButton.addActionListener(this);
        buttonPanel.add(convertButton);
        mainPanel.add(buttonPanel);

        add(mainPanel);
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String decimalString = decimalField.getText();
        if (decimalString.isEmpty()) {
            return;
        }
        try {
            int decimal = Integer.parseInt(decimalString);
            String binary = Integer.toBinaryString(decimal);
            String octal = Integer.toOctalString(decimal);
            String hexadecimal = Integer.toHexString(decimal);
            binaryField.setText(binary);
            octalField.setText(octal);
            hexadecimalField.setText(hexadecimal);
        } catch (NumberFormatException ex) {
            // do nothing
        }
    }

    public static void main(String[] args) {
        new NumberConverter();
    }

}

在这个程序中，我们使用了BoxLayout来垂直排列各个面板，使用BorderLayout将标签和文本框放在一起，使用JButton添加一个转换按钮，并在actionPerformed方法中实现将十进制整数转换成二进制、八进制和十六进制整数的逻辑。