问题
I'd like to write unicode literal U+10428 in Java. http://www.marathon-studios.com/unicode/U10428/Deseret_Small_Letter_Long_I
I tried with '\u10428' and it doesn't compile.
回答1:
Because Java went full-out unicode when people thought 64K are enough for everyone (Where did one hear such before?), they started out with UCS-2 and later upgraded to UTF-16.
But they never bothered to add an escape sequence for unicode characters outside the BMP.
Thus, your only recourse is manually recoding to a UTF-16 surrogate-pair and using two UTF-16 escapes.
Your example codepoint U+10428 is "\uD801\uDC28".
I used this site for the recoding: http://rishida.net/tools/conversion/
Quote from the docs:
3.10.5 String Literals
A string literal consists of zero or more characters enclosed in double quotes. Characters may be represented by escape sequences (§3.10.6) - one escape sequence for characters in the range U+0000 to U+FFFF, two escape sequences for the UTF-16 surrogate code units of characters in the range U+010000 to U +10FFFF.
来源：https://stackoverflow.com/questions/24633273/how-to-write-3-bytes-unicode-literal-in-java