Swing JLabel display unicode " \u21B5 " as text not working

I am working with virtual keyboard in my application. I tried to display the arrow keys in the keyboard by unicodes, Some unicodes are displaying correctly others displaying as junk.

Ex:

\u2191 - Displaying
\u21B5 - Not displaying

Solution

Make sure your OS includes a font that supports unicode.

Try one of the fonts from this list: http://unicode.org/resources/fonts.html

Alan Wood's Unicode fonts resource
Code2000, Code2001, and Code2002 (James Kass)
A shareware Unicode font
Edward Trager's index of free/libre fonts
Fonts By Range (Alan Wood)
Information on the Unicode fonts available for each Unicode range
Gallery of Unicode Fonts
Hundreds of free Unicode fonts, with sample images from each
Google Noto fonts
Intended as a source for fonts covering all scripts of The Unicode Standard, released under Apache 2.0 license. Subdirectories for hinted and unhinted versions, in bundles or individually.
Google Noto "early access" fonts
This repository contains Noto fonts that are currently under development, so they may not be stable, but are available for use and comment. (A discussion forum is available.)
GNU Unifont
This font includes glyphs for every printable code point in the Unicode Basic Multilingual Plane (BMP), and is regularly updated.
Junicode (Peter S. Baker)
A Unicode-based font for medievalists.
Last Resort Font
Link to downloading the Last Resort Font as well as its End User License Agreement
Microsoft Arial Unicode MS and Lucida Sans Unicode
Monotype fonts
SIL Fonts
George Douros' Fonts for Symbols and Ancient Scripts.
Symbola covers many of the Symbol blocks, including Unicode 8.0 characters and pictographs (emoji). Older versions of Symbola are also available at other download sites.
UniMath
An OpenType font which contains all of the TeX, LaTeX, and AMS TeX symbols, as well as hundreds of other symbols from the Unicode ranges that cover mathematical operators, arrows, and technical symbols.