Java Swing: JComboBox setEditable(true)

Question

How to limit the length of the text in Jcombobox with seteditable true to 255 characters.So that user can't enter text more then 255 characters.

Answer 1

You can get editor from the JComboBox. In the editor get a text filed used for edit. You can cast it to JTextField in the simplest case. Then add a DocumentFilter to the JTextFiled's document. Override the methods to check existing Document's length and ignore edits when limit is achieved.
    public void insertString(FilterBypass fb, int offset, String string,
                             AttributeSet attr) throws BadLocationException {
        fb.insertString(offset, string, attr);
    public void replace(FilterBypass fb, int offset, int length, String text,
                        AttributeSet attrs) throws BadLocationException {
        fb.replace(offset, length, text, attrs);
    }