Identifying Japanese Character.

[Gaurav Mac Mathur]

How can we Identify if the String has Japanse Characters. One way can be picking Charcater by Character and Identifying if thet Lie between 30A0-30FF and 3040-309F. but this is Crude. Is there any facility available with Java to do this?
Cheers

[Cindy Glass]

If there were such a facility, it would have to examine each character anyway. However I do not know of one, so you would probably be best to do it this way yourself.

[Jim Yingst]

You could do something like this:

public class JapaneseValidator {
    private final static Set japaneseBlocks = new HashSet();
    static {
        japaneseBlocks.add(Character.UnicodeBlock.KATAKANA);
        japaneseBlocks.add(Character.UnicodeBlock.HIRAGANA);
        japaneseBlocks.add(Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS);
        japaneseBlocks.add(Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A);
        // add other blocks as necessary
    }
    public static boolean isAllJapanese(String input) {
        for (int i = 0, max = input.length(); i < max; i++) {
            char c = input.charAt(i);
            Character.UnicodeBlock block = Character.UnicodeBlock.of(c);
            if (!japaneseBlocks.contains(block))
                return false;
        }
        return true;
    }
}

You'll have to look at the API for Character.UnicodeBlock to make a more complete list of blocks. And many of the chars you need are in various CJK blocks (Chinese/Japanese/Korean unified) which means that they may contain some chars that aren't really appropriate to Japanese-only usage. I think. This is a muddy issue which I don't understand much. I think you'll need to test using a lot of data, and consulting with people who know the language well (assuming you do not) to be sure your list of chars is appropriate.

[Gaurav Mac Mathur]

Thanks Jim,
This was exactly what i wanted to do.

Cheers
Gaurav

[Jim Yingst]

This was exactly what i wanted to do.
Wel, make sure you've gone through the whole list of "CJK" blocks before you say that. I have no idea what they all do, but if they say CJK they probably have something to do with Japanese...