Why do I need to escape unicode in java source files?

Please note that I'm not asking how but why. And I don't know if it's a RCP specific problem or if it's something inherent to java. My java source files are encoded in UTF-8. If I define my literal strings like this : ``` new Language("fr", "Français"), new Language("zh", "中文") ``` It works as I expect when I use the string in the application by launching it from Eclipse as an Eclipse application : But if fails when I launch the .exe built by the "Eclipse Product Export Wizard" : The solution I use is to escape the chars like this : ``` new Language("fr", "Fran\u00e7ais"), // Français new Language("zh", "\u4e2d\u6587") // 中文 ``` There is no problem in doing this (all my other strings are in properties files, only the languages names are hardcoded) but I'd like to understand. I thought the compiler had to convert the java literal strings when building the bytecode. So why is the unicode escaping necessary ? Is it wrong to use use high range unicode chars in java source files ? What happens exactly to those chars at compilation and in what it is different from the handling of escaped chars ? Is the problem just related to RCP cache ?