Completion Suggester in Elasticsearch 6.5.4 with Java REST Client API

Question

I am new to elastic search and trying to integrate the completion suggester to one of my application by following the article You Complete Me

I have inserted the sample data to the ES with mapping and the below CURL query(windows) returns the result

curl -H "Content-Type: application/json" -X POST localhost:9200/hotels/_search?pretty -d^
"{^
    \"suggest\": {^
        \"hotel_suggest\" : {^
            \"prefix\" : \"hot\", ^
            \"completion\" : { ^
                \"field\" : \"name_suggest\" ^
            }^
        }^
    }^
}"

Unfortunalty the below code using the Java API is not returning any documents from the DB (Just printing the results for the testing purpose)

    public String suggestSearch() throws IOException {
        SearchRequest searchRequest = new SearchRequest("hotels");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
//        searchSourceBuilder.query(QueryBuilders.matchAllQuery());

        SuggestionBuilder termSuggestionBuilder =
                SuggestBuilders.termSuggestion("name").text("hot");
        SuggestBuilder suggestBuilder = new SuggestBuilder();
        suggestBuilder.addSuggestion("name_suggest", termSuggestionBuilder);
        searchSourceBuilder.suggest(suggestBuilder);

        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);


        Suggest suggest = searchResponse.getSuggest();
        TermSuggestion termSuggestion = suggest.getSuggestion("name_suggest");

        for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
            for (TermSuggestion.Entry.Option option : entry) {
                String suggestText = option.getText().string();
                System.out.println(suggestText);
            }
        }
        return "SUCCESS";
    }

What is wrong in this code?

Answer 1

Here a sample code to get results from the example completion suggester

public static void suggestSearch() 
    {

        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost( "your-ip-here", 9200, "http" ) ) );

        SearchRequest searchRequest = new SearchRequest( "music" );
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();

        SuggestionBuilder termSuggestionBuilder = SuggestBuilders.completionSuggestion( "suggest" ).prefix( "nev" );
        SuggestBuilder suggestBuilder = new SuggestBuilder();
        suggestBuilder.addSuggestion( "song-suggest", termSuggestionBuilder );
        searchSourceBuilder.suggest( suggestBuilder );

        searchRequest.source( searchSourceBuilder );
        SearchResponse searchResponse = null;

        try
        {
            searchResponse = client.search( searchRequest );
        }
        catch ( IOException e )
        {
            e.printStackTrace();
        }

        Suggest suggest = searchResponse.getSuggest();
        CompletionSuggestion entries = suggest.getSuggestion( "song-suggest" );

        for ( CompletionSuggestion.Entry entry : entries )
        {
            for ( CompletionSuggestion.Entry.Option option : entry.getOptions() )
            {
                String suggestText = option.getText().string();
                System.out.println( suggestText );
            }
        }
    }

And for the example you-complete-me

public static void suggestSearch()
    {

        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost( "192.168.1.245", 9200, "http" ) ) );

        SearchRequest searchRequest = new SearchRequest( "hotels" );
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
       searchSourceBuilder.query(QueryBuilders.matchAllQuery());

        CompletionSuggestionBuilder completionSuggestionBuilder = SuggestBuilders.completionSuggestion( "name_suggest" ).prefix( "M" );

        SuggestBuilder suggestBuilder = new SuggestBuilder();
        suggestBuilder.addSuggestion( "name_suggest", completionSuggestionBuilder );
        searchSourceBuilder.suggest( suggestBuilder );

        searchRequest.source( searchSourceBuilder );
        SearchResponse searchResponse = null;

        try
        {
            searchResponse = client.search( searchRequest );
        }
        catch ( IOException e )
        {
            e.printStackTrace();
        }

        Suggest suggest = searchResponse.getSuggest();
        CompletionSuggestion entries = suggest.getSuggestion( "name_suggest" );

        for ( CompletionSuggestion.Entry entry : entries )
        {
            for ( CompletionSuggestion.Entry.Option option : entry.getOptions() )
            {
                String suggestText = option.getText().string();
                System.out.println( suggestText );
            }
        }
    }