Elasticsearch 5.4.3实战--Java API调用：搜索建议

通常的搜索引擎，都会根据用户的输入，实时给予匹配的提示。 那么这个功能在elasticsearch中如何实现呢？

Elasticsearch里设计了4种类别的Suggester，分别是:

• Term Suggester
• Phrase Suggester
• Completion Suggester
• Context Suggester

我是采用Completion Suggester来实现的。

原理的文章网上有很多，这里不多说。我们直接上代码：

 package com.cs99lzzs.elasticsearch.service.imp;

 import java.text.DecimalFormat;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;

 import javax.annotation.Resource;

 import org.apache.commons.lang.StringUtils;
 import org.apache.log4j.Logger;
 import org.apache.lucene.queryparser.classic.QueryParser;
 import org.elasticsearch.action.search.SearchRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.search.SearchType;
 import org.elasticsearch.client.Client;
 import org.elasticsearch.index.query.BoolQueryBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.index.query.QueryBuilders;
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.AggregationBuilders;
 import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.elasticsearch.search.sort.SortBuilders;
 import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.SuggestBuilder;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;

 @Service("productSearchService")
 public class ProductSearchServiceImp implements ProductSearchService {

     private static Logger logger = Logger.getLogger(ProductSearchService.class);

     private static String aggrationBrandName = "brand_count";

     private static String suggestZhName = "suggestName";

     @Resource(name="esClient")
     Client esClient;

     @Value("${elasticsearch.index}")
     private String CLUSTER_INDEX;

     @Value("${elasticsearch.type}")
     private String CLUSTER_TYPE;

     /**
      * @return
      */
     @Override
     public List<String> getSuggestList(String keyword,  int number) {
         List<String> suggestList = new ArrayList<String>();

         CompletionSuggestionBuilder suggestZhNameBuilder = new CompletionSuggestionBuilder(suggestZhName).prefix(keyword).size(100);
         SuggestBuilder suggestBuilder = new SuggestBuilder()
                 .addSuggestion(suggestZhName, suggestZhNameBuilder);
         SearchResponse suggestResponse = esClient.prepareSearch(CLUSTER_INDEX)
                 .setTypes(CLUSTER_TYPE)
 //                .setQuery(QueryBuilders.matchAllQuery())
                 .suggest(suggestBuilder)
                 .execute()
                 .actionGet();

         List<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> result1 = suggestResponse
                     .getSuggest().getSuggestion(suggestZhName).getEntries();
         for (Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option> op : result1) {
             List<? extends Suggest.Suggestion.Entry.Option> options = op.getOptions();
             if (suggestList.size() < number) {
                 for (Suggest.Suggestion.Entry.Option pp : options) {
                     if(suggestList.size() < number && !suggestList.contains(pp.getText().toString())){
                         suggestList.add(pp.getText().toString());
                     }
                 }
             }else{
                 break;
             }
         }

         return suggestList;
     }

 }