code: public static Decoder get(Charset charset) throws Exception {
  		Class<? extends Decoder> cl = decoders.get(charset.name());
  		if (cl == null) {
  			CharsetDecoder decoder = charset.newDecoder();
  			decoder.onMalformedInput(CodingErrorAction.REPLACE);
  			decoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
  			return new DefaultDecoder(decoder);
  		}
  		return cl.newInstance();
  	}
docs: Get a decoder for the given charset.