Printing Unicode characters in java

I'm developing a Sinhala-English Unicode translator on Java. When I print a Unicode character in a JTextPane, it only shows a blank box开发者_运维问答. But when I copy that box to the notepad in windows it shows me the letter. The problem is that Java not showing the Unicode characters instead windows.

How can I fix this problem ?

It's likely that the font you are using in your JTextPane does not fully support the Unicode range that you are trying to display. Try setting the text area's font to something more Unicode-friendly (see the row labeled "Sinhala (80: 0D80–0DFF)").