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POWhat is the deal with the unicode character 首(U+9996) and how java/mysql deal with it and its friends?
 

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  1. POWhat is the deal with the unicode character 首(U+9996) and how java/mysql deal with it and its friends?
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    <p>I have a java String that contains the unicode character U+9996 (that's what I get if I do codePointAt()). </p> <p>If I look at it in the debugger expressions panel (in eclipse) then all is well and it looks like "<strong>首</strong>". However if I print it out to the console I get simply "<strong>?</strong>". It doesn't seem to be the font that's the problem as I've tried setting that differently.</p> <p>My real problem is that I'm trying to put the string into a MySQL database (with utf8 encoding). Lots of other wide characters show up fine in the db but, again, this one and some others like it show up as "?". All of which leads me to believe that the problem is on the java side.</p> <p>In chasing down this bug I've learnt a little about <a href="http://en.wikipedia.org/wiki/Unicode_normalization" rel="nofollow noreferrer">Unicode Normalization</a> and java.text.<a href="http://java.sun.com/javase/6/docs/api/java/text/Normalizer.html" rel="nofollow noreferrer">Normalizer</a> which looks like it might be relevant in this case. I've learnt that U+9996 is the canonical version of U+2FB8. U+2FB8 has exactly the same problems above though as regards display and anyway why would I want to transform to a non-canonical representation (even if I could, which I don't think I can)?</p> <p>Anyway, there's one potential clue I've found which I've been unable to comprehend. <a href="http://www.fileformat.info/info/unicode/char/9996/index.htm" rel="nofollow noreferrer">This page</a> contains the words "U+9996 is not a valid unicode character" with no further explanation. It then proceeds to show how to encode this supposedly non-valid unicode character in various unicode encodings. So my question is this basically: WTF?</p> <hr> <h2>UPDATES</h2> <ul> <li>I'm on a Mac.</li> <li>I'm talking about the Eclipse console. <ul> <li>I set the console encoding to UTF-8 under Run > Common</li> <li>I added <code>-Dfile.encoding=UTF-8</code> to the JVM arguments (the default was MacRoman)</li> <li>The console (Eclipse and Terminal.app) now show the right chars. Hooray!</li> </ul></li> <li>I'm mostly interested in the data getting into the database correctly though of course I'd like to get a total understanding of what's going on here. </li> <li>I think I've fixed the database problem. I forgot to set the encoding on the <em>connection</em>. Now I don't understand why some asian characters were getting through and not others.</li> <li>Phew, stackoverflow moves fast. It's hard to keep up. Thanks people.</li> </ul>
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    1. COU+9996 is a perfectly valid character, it's a Han ideograph. See http://www.unicode.org/cgi-bin/GetUnihanData.pl?codepoint=9996
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      1. POWhat is the deal with the unicode character 首(U+9996) and how java/mysql deal with it and its friends?
      1. USAdam Rosenfield
    2. COIf you're using Windows, the only way to write Unicode characters to the console is WriteConsoleW: http://msdn.microsoft.com/en-us/library/ms683458.aspx Java's source code (OpenJDK 6) contains no references to WriteConsole, therefore writing Unicode chars to the console from Java is impossible.
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      1. POWhat is the deal with the unicode character 首(U+9996) and how java/mysql deal with it and its friends?
      1. USChris Jester-Young
    3. COLike other posters have said, though, the char is still valid, just will always show up as ? on the console.
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      1. USChris Jester-Young
 

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