title: How to convert UTF-8 to unicode in Java?
body: <p>For example, in Emoji Char set, <code>U+1F601</code> is the unicode value for "GRINNING FACE WITH SMILING EYES", and <code>\xF0\x9F\x98\x81</code> is the UTF-8 bytes value for this character.</p>
  
  <p><code>\xE2\x9D\xA4</code> is for heavy black heart, and the unicode is <code>U+2764</code>.</p>
  
  <p>So my question is, if I have a byte array with value <code>(0xF0, 0x9F, 0x98, 0x81, 0xE2, 0x9D, 0xA4)</code>, then how I can convert it into Unicode value?</p>
  
  <p>For the above result, what I want is a String array with value <code>"1F601"</code> and <code>"2764"</code>.</p>
  
  <p>I know I can write a complex method to do this work, but I hope there is already a library to do this work.</p>