Хорошо, вот мое собственное решение:
public List<String> getSuggestion(String input) throws IOException {
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
SuggestionBuilder termSuggestionBuilder = SuggestBuilders.completionSuggestion("my_index_suggest").text(input);
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_field", termSuggestionBuilder);
searchSourceBuilder.suggest(suggestBuilder);
SearchRequest searchRequest = new SearchRequest();
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = suggestionIndexClient.search(searchRequest, RequestOptions.DEFAULT);
return StreamSupport.stream(Spliterators.spliteratorUnknownSize(searchResponse.getSuggest().iterator(), Spliterator.ORDERED), false)
.flatMap(suggestion -> suggestion.getEntries().get(0).getOptions().stream())
.map((Suggest.Suggestion.Entry.Option option) -> option.getText().toString())
.collect(Collectors.toList());
}
Если вам не нравятся потоки, не стесняйтесь использовать это универсальное предложение чудовищности плюс цикл while, который никто не просил:
Iterator<Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>>> iterator = searchResponse.getSuggest().iterator();
Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> suggestion;
List<String> resultList = null;
while (iterator.hasNext()) {
suggestion = iterator.next();
resultList = fn.getEntries().get(0).getOptions().stream()
.map((Suggest.Suggestion.Entry.Option option) -> option.getText().toString())
.collect(Collectors.toList());
}
return resultList;