Cambios realizados:

Quedan aun 3 fallos que no consigo ver. Son los siguientes:

    [javac] Compiling 1 source file to /media/sf_Practicas_Julio/SOSSwStack/sos-ws/servicio/build/classes
    [javac] /media/sf_Practicas_Julio/SOSSwStack/sos-ws/servicio/src/es/upm/fi/sos/t3/travelagency/TravelAgencyWSSkeleton.java:393: exception es.upm.fi.sos.t3.travelagency.NotValidCityHotelError is never thrown in body of corresponding try statement
    [javac] 	catch(NotValidCityHotelError e){
    [javac] 	^
    [javac] /media/sf_Practicas_Julio/SOSSwStack/sos-ws/servicio/src/es/upm/fi/sos/t3/travelagency/TravelAgencyWSSkeleton.java:383: unreported exception es.upm.fi.sos.t3.hotelbooking.NotValidCityError; must be caught or declared to be thrown
    [javac] 	    String[] hoteles = hb.getHotelList(ciudad).getHotel();
    [javac] 	                                      ^
    [javac] /media/sf_Practicas_Julio/SOSSwStack/sos-ws/servicio/src/es/upm/fi/sos/t3/travelagency/TravelAgencyWSSkeleton.java:440: unreported exception es.upm.fi.sos.t3.hotelbooking.NotValidCityError; must be caught or declared to be thrown
    [javac] 	    BookingHotelResponse bh_resp = hb.bookHotel(bh);