java - Display an Unicode character on JButton

Question

I'm trying to display this Unicode "uD83D" on a JButton text, but when I compile it just shows the square of an unknown character.

Answer 1

Thomas gave a good answer, but note that in order to avoid guessing which installed fonts support a character or string, we can iterate the available fonts and check each using the canDisplayUpTo overloaded methods of Font:

• Font.canDisplayUpTo(String)
• Font.canDisplayUpTo(CharacterIterator,start,limit)
• Font.canDisplayUpTo(char[],start,limit)

E.G.

import java.awt.Font;
import java.awt.GraphicsEnvironment;

public class FontCheck {

    public static void main(String[] args) {
        String s = "u4E33";
        Font[] fonts = GraphicsEnvironment.
                getLocalGraphicsEnvironment().getAllFonts();
        System.out.println("Total fonts: " + fonts.length);
        int count = 0;
        for (Font font : fonts) {
            if (font.canDisplayUpTo(s) < 0) {
                count++;
                System.out.println(font.getName());
            }
        }
        System.out.println("Compatible fonts: " + count);
    }
}

Output:

Total fonts:    391
Arial Unicode MS
Dialog.bold
Dialog.bolditalic
Dialog.italic
Dialog.plain
DialogInput.bold
DialogInput.bolditalic
DialogInput.italic
DialogInput.plain
Microsoft JhengHei
Microsoft JhengHei Bold
Microsoft JhengHei Light
Microsoft JhengHei UI
Microsoft JhengHei UI Bold
Microsoft JhengHei UI Light
Microsoft YaHei
Microsoft YaHei Bold
Microsoft YaHei Light
Microsoft YaHei UI
Microsoft YaHei UI Bold
Microsoft YaHei UI Light
Monospaced.bold
Monospaced.bolditalic
Monospaced.italic
Monospaced.plain
NSimSun
SansSerif.bold
SansSerif.bolditalic
SansSerif.italic
SansSerif.plain
Serif.bold
Serif.bolditalic
Serif.italic
Serif.plain
SimSun
Compatible fonts:   35