Why can't I use the 'u000a' and 'u000d' Unicode character literals in Java source code?

This is an unfortunate artifact of the ordering of the processing of the Java source file into lexemes and tokens by the compiler. Instead, you should use the equivalent character escape sequences: ' ' and ' '.

Also see What character escape sequences are available in Java?

For the full scoop on the order of processing, see chapter 3 of the JLS v2 (particularly 3.10.4, 3.2, and 3.3).