How to convert UTF-8 to unicode in Java?

Question

For example, in Emoji Char set, U+1F601 is the unicode value for "GRINNING FACE WITH SMILING EYES", and \xF0\x9F\x98\x81 is the UTF-8 bytes value for this character.

\xE2\x9D\xA4 is for heavy black heart, and the unicode is U+2764.

So my question is, if I have a byte array with value (0xF0, 0x9F, 0x98, 0x81, 0xE2, 0x9D, 0xA4), then how I can convert it into Unicode value?

For the above result, what I want is a String array with value "1F601" and "2764".

I know I can write a complex method to do this work, but I hope there is already a library to do this work.

Answer 1

So my question is, if I have a byte array with value (0xF0, 0x9F, 0x98, 0x81), then how I can convert it into Unicode value?

Simply call the String constructor specifying the data and the encoding:

String text = new String(bytes, "UTF-8");

You can specify a Charset instead of the name of the encoding - I like Guava's simple Charsets class, which allows you to write:

String text = new String(bytes, Charsets.UTF_8);

Or for Java 7, use StandardCharsets without even needing Guava:

String text = new String(bytes, StandardCharsets.UTF_8);

Answer 2

Simply use String class:

byte[] bytesArray = new byte[10]; // array of bytes (0xF0, 0x9F, 0x98, 0x81)

String string = new String(bytesArray, Charset.forName("UTF-8")); // covert byteArray

System.out.println(string); // Test result