Name: auR10023 Date: 02/20/2003



CharsetEncoder.canEncode(char) returns true with surrogate unicode
characters in UTF-8 but javadoc for this method says:

...
This method returns false if the given character is a surrogate
character; such characters can be interpreted only when they are members
of a pair consisting of a high surrogate followed by a low surrogate
...

Here is the example:

------------- test.java --------------

import java.nio.charset.*;

public class test {

    static char [] illChrs = {
        '\ud800', '\ud801', '\udffe', '\udfff'
    };


    public static void main (String[] args) {
        CharsetEncoder en = null;
        try {
            en = Charset.forName("UTF-8").newEncoder();
        } catch(IllegalArgumentException e) {
            e.printStackTrace(System.out);
            System.out.println("Unexpected " + e);
            return;
        }
 
        for (int j = 0; j < illChrs.length; j++) {
            if (en.canEncode((char)j)) {
                System.out.println("Unexpected value returned with " +
                                   (int)illChrs[j]);
            }
        }
    }
}

#java -version
java version "1.4.2-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-beta-b16)
Java HotSpot(TM) Client VM (build 1.4.2-beta-b16, mixed mode)

#java test

Unexpected value returned with 55296
Unexpected value returned with 55297
Unexpected value returned with 57342
Unexpected value returned with 57343


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