MultipartFormDataEntityProvider implements EntityProvider<Iterator<FileItem>> { @Override public void writeTo(Iterator<FileItem> t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException { throw new UnsupportedOperationException(); } MultipartFormDataEntityProvider(@Context HttpServletRequest httpRequest); @Override boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType); @Override @SuppressWarnings("unchecked") Iterator<FileItem> readFrom(Class<Iterator<FileItem>> type,
                                       Type genericType,
                                       Annotation[] annotations,
                                       MediaType mediaType,
                                       MultivaluedMap<String, String> httpHeaders,
                                       InputStream entityStream); @Override long getSize(Iterator<FileItem> t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType); @Override boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType); @Override void writeTo(Iterator<FileItem> t,
                        Class<?> type,
                        Type genericType,
                        Annotation[] annotations,
                        MediaType mediaType,
                        MultivaluedMap<String, Object> httpHeaders,
                        OutputStream entityStream);  }
@Test(expected = UnsupportedOperationException.class) public void writeToIsNotSupported() throws Exception { formDataEntityProvider.writeTo(null, null, null, null, null, null, null); }