使用 Java API 的 ElasticSearch 完成建议器

Question

我在网上尝试了一些关于 ElasticSearch 的建议功能的示例代码，但我无法解决自动完成解决方案的问题

我的索引：

client.prepareIndex("kodcucom", "article", "1")
      .setSource(putJsonDocument("ElasticSearch: Java",
        "ElasticSeach provides Java API, thus it executes all operations " +
        "asynchronously by using client object..",
         new Date(),
         new String[]{"elasticsearch"},
         "Hüseyin Akdoğan")).execute().actionGet();

我使用suggestbuilder获取关键字然后扫描内容“字段”，这里是由于没有结果而发生空指针异常的地方

CompletionSuggestionBuilder skillNameSuggest = new CompletionSuggestionBuilder("skillNameSuggest");

skillNameSuggest.text("lien");
skillNameSuggest.field("content");

SuggestRequestBuilder suggestRequestBuilder = client.prepareSuggest("kodcucom").addSuggestion(skillNameSuggest);

SuggestResponse suggestResponse = suggestRequestBuilder.execute().actionGet();

Iterator<? extends Suggest.Suggestion.Entry.Option> iterator =
          suggestResponse.getSuggest().getSuggestion("skillNameSuggest").iterator().next().getOptions().iterator();

为了获得结果，我是否遗漏了一些过滤器或输入条件？任何结果都应该没问题，例如自动完成或找到记录。

编辑 1：

这是我获得 NPE 的地方，我可以看到在调试模式下 suggestResponse 处没有返回任何结果

Iterator<? extends Suggest.Suggestion.Entry.Option> iterator =
              suggestResponse.getSuggest().getSuggestion("skillNameSuggest").iterator().next().getOptions().iterator();

编辑 2： 我正在使用 2.1.1 版本的 ElasticSearch Java API

编辑 3： 我尝试将迭代器行拆分为几个代码块，将一组数据转换为迭代器时，NPE出现在最后一行，但没有太大帮助

Suggest tempSuggest = suggestResponse.getSuggest();

Suggestion tempSuggestion = tempSuggest.getSuggestion("skillNameSuggest");

Iterator tempIterator = tempSuggestion.iterator();

我看到代码：

SuggestRequestBuilder suggestRequestBuilder = client.prepareSuggest("kodcucom").addSuggestion(skillNameSuggest);

    SuggestResponse suggestResponse = suggestRequestBuilder.execute().actionGet();

已经包含一个空数组/数据集，我是否错误地使用了建议请求生成器？

Answer 1

为了使用补全功能，您需要指定一个字段，称为补全，您必须为其指定一个特殊的映射。

例如：

"mappings": {
   "article": {
     "properties": {
      "content": {
        "type": "string"
      },
     "completion_suggest": {
      "type": "completion"}
     }
   }
}

completion_suggest 字段是我们将用于上述代码示例中的自动完成功能的字段。在这个映射定义之后，数据必须被索引如下：

curl -XPOST localhost:9200/kodcucom/article/1 -d '{
   "content": "elasticsearch",
   "completion_suggest": {
     "input": [ "es", "elastic", "elasticsearch" ],
     "output": "ElasticSearch"
   }
}'

那么可以使用Java API如下获取建议：

CompletionSuggestionBuilder skillNameSuggest  = new CompletionSuggestionBuilder("complete");
skillNameSuggest.text("es");
skillNameSuggest.field("completion_suggest");

SearchResponse searchResponse = client.prepareSearch("kodcucom")
        .setTypes("article")
        .setQuery(QueryBuilders.matchAllQuery())
        .addSuggestion(skillNameSuggest)
        .execute().actionGet();

CompletionSuggestion compSuggestion = searchResponse.getSuggest().getSuggestion("complete");

List<CompletionSuggestion.Entry> entryList = compSuggestion.getEntries();
if(entryList != null) {
    CompletionSuggestion.Entry entry = entryList.get(0);
    List<CompletionSuggestion.Entry.Option> options =entry.getOptions();
    if(options != null)  {
        CompletionSuggestion.Entry.Option option = options.get(0);
        System.out.println(option.getText().string());
    }
}

Answer 2

以下链接为您提供了如何创建建议者索引的详细信息。 https://www.elastic.co/blog/you-complete-me

现在，我使用异步 Suggestionbuilder Java API 来根据术语生成建议。

 SearchRequestBuilder suggestionsExtractor = elasticsearchService.suggestionsExtractor("yourIndexName", "yourIndexType//not necessary", "name_suggest", term);
        System.out.println(suggestionsExtractor);
        Map<String,Object> suggestionMap = new HashMap<>();
        suggestionsExtractor.execute(new ActionListener<SearchResponse>() {
            @Override
            public void onResponse(SearchResponse searchResponse) {
               if(searchResponse.status().equals(RestStatus.OK)) {
                   searchResponse.getSuggest().getSuggestion("productsearch").getEntries().forEach(e -> {
                       e.getOptions().forEach(s -> {
                           ArrayList<Object> contents = new ArrayList<>();

                           suggestionMap.put(s.getText().string(), s.getScore());

                       });
                   });


               }

            }

            @Override
            public void onFailure(Exception e) {
                Helper.sendErrorResponse(routingContext,new JsonObject().put("details","internal server error"));
                e.printStackTrace();
            }
        });

以下是建议生成器的创建方式。

public SearchRequestBuilder suggestionsExtractor(String indexName, String typeName, String field, String term) {

        CompletionSuggestionBuilder csb = SuggestBuilders.completionSuggestion(field).text(term);
        SearchRequestBuilder suggestBuilder = client.prepareSearch()
                .suggest(new SuggestBuilder().addSuggestion(indexName, csb));
        return suggestBuilder;
    }