es7.16版本向量检索api java

Question

需要java的 es7.16版本向量检索api 和dsl语句
使用es自带的余弦相似度
支持1-6个的图片向量检索(向量已存在512维）
1-6个图片可同时参与检索，且是or的关系，需要分别返回得到倒叙前topn
可以设置得分，过滤指定分数以上的结果
可以取topn

Answer 1

参考：使用Java API实现ES 7.16版本的向量检索和DSL语句：

1. 向量检索API

import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.lucene.search.function.FunctionScoreQuery;
import org.elasticsearch.common.lucene.search.function.FunctionScoreQueryBuilder;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.index.query.functionscore.WeightBuilder;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.script.ScriptType;
import org.elasticsearch.script.mustache.SearchTemplateRequestBuilder;

public class VectorSearch {
    private RestHighLevelClient client;

    public VectorSearch(RestHighLevelClient client) {
        this.client = client;
    }

    public SearchResponse search(String index, String field, float[] vector, int topN, float minScore) throws IOException {
        // 构建查询条件
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        for (int i = 0; i < vector.length; i++) {
            FunctionScoreQueryBuilder.FilterFunctionBuilder[] functions = new FunctionScoreQueryBuilder.FilterFunctionBuilder[vector.length];
            functions[i] = new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                    ScoreFunctionBuilders.weightFactorFunction(vector[i]),
                    new WeightBuilder().setWeight(vector[i])
            );
            boolQuery.should(QueryBuilders.functionScoreQuery(
                    QueryBuilders.matchAllQuery(),
                    functions
            ));
        }

        // 设置查询参数
        SearchRequest searchRequest = new SearchRequest(index);
        searchRequest.source().query(boolQuery)
                .size(topN)
                .minScore(minScore)
                .timeout(TimeValue.timeValueSeconds(10));

        // 执行查询
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        if (searchResponse.status() != RestStatus.OK) {
            throw new RuntimeException("Failed to execute search");
        }
        
        return searchResponse; 
    }
}

1. DSL语句

{
  "query": {
    "bool": {
      "should": [
        {
          "function_score": {
            "query": { "match_all": {} },
            "functions": [
              { "weight_factor": { "field1": 0.1 } }
            ]
          }
        },
        {
          "function_score": {
            "query": { "match_all": {} },
            "functions": [
              { "weight_factor": { "field2": 0.2 } }
            ]
          }
        },
       ...
      ]
    }
  },
  "_source" : false,
  "size" : topN,
  "min_score" : minScore
}

其中，field1、field2等表示不同的图片向量字段，可以根据实际情况进行修改。