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;
    }

}