试了网上的设置Font，或将汉字使用new String(str.getBytes(),"GBK")对展示的汉字进行编码。都无效。
解决办法：
（1）更改项目的编码为GBK，汉字可以正式显示（2）将java.awt.Button更改为javax.swing.JButton
import java.awt.BorderLayout;import java.awt.FlowLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.IOException;import java.util.Calendar;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.SwingUtilities;public class CloseComputer extends JFrame implements ActionListener { private static final long serialVersionUID = 1L; // 创建实现BorderLayout布局的面板对象panelmain,用于放panelSubnorth面板和panelSubcenter面板 private JPanel panelMain; // 创建实现FlowLayout布局的面板对象panelSubnorth,用于放tag提示标签 private JPanel panelSubnorth; // 创建实现FlowLayout布局的面板对象panelSubcenter,用于放3个按钮 private JPanel panelSubcenter; // 创建三个按钮 private JButton countdown; private JButton time; private JButton cancel; private String key; // 创建一个提示标签 private JLabel tag; public CloseComputer() { initComponents(); } public void initComponents() { panelMain = new JPanel(new BorderLayout(5, 10)); panelSubnorth = new JPanel(new FlowLayout(3)); panelSubcenter = new JPanel(new FlowLayout(1, 5, 5)); countdown = new JButton("倒计时关机"); time = new JButton("定时关机"); cancel = new JButton("取消关机"); tag = new JLabel("请选择关机方式"); // 将panelMain添加到窗体中 this.getContentPane().add(panelMain); // 添加对象panelSubnorth到对象panelMain窗口里 panelMain.add(panelSubnorth, BorderLayout.NORTH); // 添加对象panelSubcenter到对象panelMain窗口里 panelMain.add(panelSubcenter, BorderLayout.CENTER); // 添加标签对象tag到对象panelSubnorth窗口里 panelSubnorth.add(tag); // 添加3个按钮到对象panelSubcenter里 panelSubcenter.add(countdown); panelSubcenter.add(time); panelSubcenter.add(cancel); // 为3个按钮注册事件监听器 countdown.addActionListener(this); time.addActionListener(this); cancel.addActionListener(this); } /** * 倒计时关机 */ public void countdown() { key = JOptionPane.showInputDialog(this, "请输入倒计时关机剩余的时间(秒)", "输入框", JOptionPane.INFORMATION_MESSAGE); String command = "shutdown -s -t " + key; executeCommand(command); } /** * 定时关机 */ public void time() { Calendar calendar = Calendar.getInstance(); int h = calendar.get(Calendar.HOUR); // 获取小时 int m = calendar.get(Calendar.MINUTE); // 获取分钟 int s = calendar.get(Calendar.SECOND); // 获取秒 // 输入时间 String hourInputValue, minuteInputValue, secordInputValue; // 保存输入的时间 hourInputValue = JOptionPane.showInputDialog(this, "请输入关机的小时(12小时制)", "输入", JOptionPane.INFORMATION_MESSAGE); minuteInputValue = JOptionPane.showInputDialog(this, "请输入关机的分钟", "输入", JOptionPane.INFORMATION_MESSAGE); secordInputValue = JOptionPane.showInputDialog(this, "请输入关机的秒钟", "输入", JOptionPane.INFORMATION_MESSAGE); // 转换时间 int hour, minute, secord; // 保存转换后的时间 hour = Integer.parseInt(hourInputValue); minute = Integer.parseInt(minuteInputValue); secord = Integer.parseInt(secordInputValue); long setTime = timeSum(hour, minute, secord); // 计算输入时间的总和 long currentlyTime = timeSum(h, m, s); // 计算当前系统时间的总和 long discrepancyTime = setTime - currentlyTime; // 获取时间差 if (discrepancyTime < 0) { String command = "shutdown -s"; executeCommand(command); } else { String command = "shutdown -s -t " + discrepancyTime; executeCommand(command); JOptionPane.showMessageDialog(this, "恭喜你,设置成功!", "确认", JOptionPane.WARNING_MESSAGE); } } private void executeCommand(String command) { try { Runtime.getRuntime().exec(command); } catch (IOException e) { e.printStackTrace(); } } /** * 计算出时间总和,并返回 */ public int timeSum(int h, int m, int s) { return h * 3600 + m * 60 + s; } /** * 取消关机 */ public void cancel() { JOptionPane.showMessageDialog(this, "你已经成功取消了关机操作!", "消息", JOptionPane.WARNING_MESSAGE); String command = "shutdown -a"; executeCommand(command); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { CloseComputer frame = new CloseComputer(); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); frame.setResizable(false); frame.setTitle("关机工具"); frame.setSize(400, 400); frame.setLocationRelativeTo(null); frame.pack(); frame.setVisible(true); } }); } @Override public void actionPerformed(ActionEvent e) { if (e.getSource() == countdown) { countdown(); } if (e.getSource() == time) { time(); } if (e.getSource() == cancel) { cancel(); } }}