question: public String encodeKey ( final String key ) { if ( StringUtils . isEmpty ( key ) ) { throw new IllegalArgumentException ( "Key cannot be empty" ) ; } try { return Hex . encodeHexString ( key . getBytes ( "UTF-8" ) ) ; } catch ( UnsupportedEncodingException uee ) { throw new IllegalStateException ( uee ) ; } }
target:  Encode the given key to Hexadecimal.