Java textcomponent中的ASCII不可打印字符

我的情况是，我必须扫描文本字段中的qrcode，我必须解析该文本字段中的非可打印字符（顺便说一句，它总是同一个字符），这些字符永远不会出现在同一位置

我尝试获取此代码，但今年没有成功

• textfield.getText（）失败
• textfield.getDocument（）.getText（0，textfield.getDocument（）.getLength（））失败

我成功地使用了

KeyBindings

，然后用glyph替换为@trashgod注释

例如：

public class Test {

    private JPanel panel;
    private JTextArea textArea;

    public static final String GS_UNICODE = "\u241D";

    public Test(){
        panel = new JPanel();
        textArea = new JTextArea(10,30);
        final JTextField textfield = new JTextField(30);

        textfield.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke(KeyEvent.VK_F8,0), "test");
        textfield.getActionMap().put("test", new AbstractAction(){

            @Override
            public void actionPerformed(ActionEvent e) {
                textfield.setText(textfield.getText()+GS_UNICODE);                
            }

        });



        textfield.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent e) {                
                    textArea.setText(textfield.getText());                                   
            }
        });
        panel.add(textfield);
        JButton button = new JButton("Press non-readable");
        button.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    Robot robot = new Robot();
                    textfield.requestFocusInWindow();                    
                    robot.setAutoDelay(10);
                    robot.keyPress(KeyEvent.VK_F8);
                    robot.keyPress(KeyEvent.VK_H);
                    robot.keyPress(KeyEvent.VK_E);
                    robot.keyPress(KeyEvent.VK_L);
                    robot.keyPress(KeyEvent.VK_L);
                    robot.keyPress(KeyEvent.VK_O);
                    robot.keyPress(KeyEvent.VK_ENTER);  

                    SwingUtilities.invokeLater(new Runnable(){

                        @Override
                        public void run() {
                            //check if string has glyph
                           System.out.println(textfield.getText().contains(GS_UNICODE));
                           System.out.println(textfield.getText());
                        }

                    });

                } catch (AWTException ex) {
                    ex.printStackTrace();
                }

            }

        });
        panel.add(button);
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("DataMatrix example");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        frame.setLocationByPlatform(Boolean.TRUE);
        Test example =new Test();
        frame.add(example.panel,BorderLayout.CENTER);
        frame.add(example.textArea,BorderLayout.SOUTH);

        //Display the window.
        frame.pack();
        frame.setVisible(Boolean.TRUE);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }


}

但我的问题是：

---

1） 有没有一种方法可以捕获不可打印的ASCII码（你能在这里发布这样一个字符串吗？你不能捕获哪些字符？你是在寻找这样的标志符号：？我不一样****，：-）以便更快地发布SSCCE/MCVE/MCTRE短的、可运行的、可编译的局部变量中的硬编码值，顺便说一句（？？我肯定？？）@Andrew Thompson在您的帖子和/或question@trashgod我希望编辑的问题更容易理解，是的，字形帮助很大：）@mKorbel我发布了一个例子