Is Java UTF-8 Charset exception possible?

It's supposed to be present in every Java runtime, so it is reasonable to re-throw a runtime exception if it is missing. I wouldn't call that "suppressing," though. To me, suppressing means catching the exception and pretending it didn't happen; not sure how you'd proceed if the encoding is missing.

According to the Javadoc for Charset, every Java implementation must support UTF-8, along with a few other charsets. Therefore, I think you can safely suppress the exception; unless you have a non-compliant Java implementation, this shouldn't be able to fail.

The most simple way is to create a UTF-8 charset constant. Then you don't have to catch the UnsupportedEncodingException again and again:

public class Charsets {
    public static final Charset UTF_8 = Charset.forName("UTF-8");
}

Edit (2014-04):

With Java 7 you don't have to create your own constant. You can simply use StandardCharsets.UTF_8 instead.

As McDowell noted in a comment to templatetypdef's answer: If you use a Charset object when you instantiate a new String instead of passing the name of the charset, you don't have to deal with an UnsupportedEncodingException or any other checked exception:

byte[] bytes = ...;

// Requires you to handle UnsupportedEncodingException
String s1 = new String(bytes, "UTF-8");

// Doesn't require you to handle any checked exceptions
String s2 = new String(bytes, Charset.forName("UTF-8"));

It's an inconsistency in Java's standard library that we have to live with...

Note that Charset.forName(...) can throw exceptions (IllegalCharsetNameException, IllegalArgumentException, UnsupportedCharsetException), but these are all unchecked exceptions, so you don't have to catch or re-throw them yourself.

edit - Since Java 7 there's class java.nio.charset.StandardCharsets which has constants for frequently used character encodings. Example:

String s3 = new String(bytes, StandardCharsets.UTF_8);