UTF-16 编码附加额外字节

Question

import java.io.UnsupportedEncodingException;
import java.util.Arrays;

public class UnicodeConversion
{
    public static void main(String[] args) throws UnsupportedEncodingException
    {
        String jaString = new String("\u20AC");
        System.out.println(jaString);
        System.out.println(Arrays.toString(jaString.getBytes("UTF-16")));
    }
}

In the UTF-16 encoding mechanism explained in https://en.wikipedia.org/wiki/UTF-16 \€ (Euro Symbol) should take only single 16 bit char value, ie 2 bytes. But I am seeing the output as 4 bytes

The output I receive is below

[-2, -1, 32, -84]

Could you explain me how the values -2 and -1 have come? I have run this with Jdk 11

Answer 1

The first two bytes is a Byte-Order Mark that determines the endianness of the 16-bit values.

0xFE, 0xFF = -2, -1 meaning you've got Big-Endian byte order.

Use "UTF-16LE" or "UTF-16BE" instead to omit the BOM.