How to convert Strings to and from UTF8 byte arrays in Java

Question

In Java, I have a String and I want to encode it as a byte array (in UTF8, or some other encoding). Alternately, I have a byte array (in some known encoding) and I want to c

Answer 1

If you are using 7-bit ASCII or ISO-8859-1 (an amazingly common format) then you don't have to create a new java.lang.String at all. It's much much more performant to simply cast the byte into char:

Full working example:

for (byte b : new byte[] { 43, 45, (byte) 215, (byte) 247 }) {
    char c = (char) b;
    System.out.print(c);
}

If you are not using extended-characters like Ä, Æ, Å, Ç, Ï, Ê and can be sure that the only transmitted values are of the first 128 Unicode characters, then this code will also work for UTF-8 and extended ASCII (like cp-1252).