Check if a String is valid UTF-8 encoded in Java

Question

How can I check if a string is in valid UTF-8 format?

Answer 1

Only byte data can be checked. If you constructed a String then its already in UTF-16 internally.

Also only byte arrays can be UTF-8 encoded.

Here is a common case of UTF-8 conversions.

String myString = "\u0048\u0065\u006C\u006C\u006F World"; System.out.println(myString); byte[] myBytes = null;  try  {     myBytes = myString.getBytes("UTF-8"); }  catch (UnsupportedEncodingException e) {     e.printStackTrace();     System.exit(-1); }  for (int i=0; i < myBytes.length; i++) {     System.out.println(myBytes[i]); } 

If you don't know the encoding of your byte array, juniversalchardet is a library to help you detect it.