The encoding 'UTF-8' is not supported by the Java runtime

Question

Whenever I start our Apache Felix (OSGi) based application under SUN Java ( build 1.6.0_10-rc2-b32 and other 1.6.x builds) I see the following message output on the console (usually under Ubuntu 8.4):

Warning: The encoding 'UTF-8' is not supported by the Java runtime.

I've seen this message display occasionally when running both Tomcat and Resin as well. If java supports unicode and UTF-8, what causes this message? I've yet to find any reference, or answer to this anywhere else.

Answer 1

According the documentation "Every implementation of the Java platform is required to support the following standard charsets... US-ASCII, ISO-8859-1, UTF-8, UTF-16BE, UTF-16LE, UTF-16." So I doubt that Sun have released a build without UTF-8 support.

The actual error message appears to be from here, which is part of the Xerces XML parser. I imagine it is the XML parser where the problem is occurring.

Answer 2

Try the following program:

import java.nio.charset.Charset;

public class TestCharset {
    public static void main(String[] args) {
        System.out.println(Charset.forName("UTF-8"));
    }
}

If this throws an exception, then there is something wrong with your JDK. If it prints "UTF-8" then your JDK is OK, and your application is doing something odd.

If that's the case, run your app under the debugger, and put a breakpoint in http://www.java2s.com/Open-Source/Java-Document/XML/xalan/org/apache/xml/serializer/ToStream.java.htm --that's the place this warning is produced, and step to see why Xalan can't find the encoding.