使用编辑器验证表的单元格

Question

我的JTable有一个密码字段编辑器.我想在用户单击编辑另一个字段时,如果文本长度小于8位,则显示错误消息.我尝试过焦点听众.但它不起作用.请帮帮我,因为我刚刚开始使用java swing.

class PasswordEditor extends DefaultCellEditor 
{

    TextBox m_passWord = new TextBox(); 
    public PasswordEditor() {
        super(new TextBox());
    }

    @Override
    public Object getCellEditorValue() {

        return this.m_passWord.getText();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {

        Object fieldValue = value;
        if(null == fieldValue)
            fieldValue = Constants.EMPTY_STRING;

        this.m_passWord.addInputMethodListener(new InputMethodListener() {

            @Override
            public void inputMethodTextChanged(InputMethodEvent event)
            {
                // TODO Auto-generated method stub

            }

            @Override
            public void caretPositionChanged(InputMethodEvent event)
            {
                // TODO Auto-generated method stub

            }
        })
        this.m_passWord.addFocusListener(new FocusListener() {

            @Override
            public void focusLost(FocusEvent e)
            {
                if (!e.isTemporary()) {
                      String content = PasswordEditor.this.m_passWord.getText();
                      System.out.println((content));
                }

            }

            @Override
            public void focusGained(FocusEvent e)
            {
                //TODO init
            }
        });

        this.m_passWord.setEditable(true);
        this.m_passWord.setText(fieldValue.toString());
        return this.m_passWord;
    }


}

Answer 1

据我所知,这是关于验证编辑器中的输入(保护自身免受无效值的模型是另一个故事,IMO)并在他/她尝试提交输入时通知用户他/她的错误.

这样做的一个简单方法是使用InputVerifier:

• 在其验证方法中实现验证规则
• 在其shouldYieldFocus中实现通知
• 子类DefaultCellEditor并覆盖其stopCellEditing以调用shouldYieldFocus并返回其结果(又名:拒绝提交编辑)

一些代码片段:

final InputVerifier iv = new InputVerifier() {

    @Override
    public boolean verify(JComponent input) {
        JTextField field = (JTextField) input;
        return field.getText().length() > 8;
    }

    @Override
    public boolean shouldYieldFocus(JComponent input) {
        boolean valid = verify(input);
        if (!valid) {
            JOptionPane.showMessageDialog(null, "invalid");
        }
        return valid;
    }

};
DefaultCellEditor editor = new DefaultCellEditor(new JTextField()) {
    {
        getComponent().setInputVerifier(iv);
    }

    @Override
    public boolean stopCellEditing() {
        if (!iv.shouldYieldFocus(getComponent())) return false;
        return super.stopCellEditing();
    }

    @Override
    public JTextField getComponent() {
        return (JTextField) super.getComponent();
    }

};

JTable table = new JTable(10, 2);
table.setDefaultEditor(Object.class, editor);

Answer 2

覆盖stopCellEditing()并在其中实现条件.

 class PasswordEditor extends DefaultCellEditor 
{

    TextBox m_passWord = new TextBox(); 
    public PasswordEditor() {
        super(new TextBox());
    }

            @Override
    public boolean stopCellEditing()
    {
        if(getCellEditorValue().toString().length() < 8)
        {
            JOptionPane.showMessageDialog(UsmUserView.this.m_Parent, "Password Must Be 8 Bytes Long !! Please Check");
            return false;
        }
        fireEditingStopped();
        return true;
    }

    @Override
    public Object getCellEditorValue() {

        return this.m_passWord.getText();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {

        Object fieldValue = value;
        if(null == fieldValue)
            fieldValue = Constants.EMPTY_STRING;

        this.m_passWord.setEditable(true);
        this.m_passWord.setText(fieldValue.toString());
        return this.m_passWord;
    }


}