在工作中遇到ElasticSearch版本升级时出现Java High Level接口变更导致的兼容性问题：之前使用的是2.4.x，考虑性能和功能的增强，需要更换为6.4.x; 2.4.x中我们使用DSL语句直接查询（数据的不确定性和方便动态建立查询规则等因素），而新的ES Java 高阶API中去掉了相关接口的支持。 此文主要记录通过 ES Wrapper Query实现对6.x版本中 Java high-level transport client对json DSL查询对支持。
实现方式理论基础
- Wrapper Query 官网说明
https://www.elastic.co/guide/en/elasticsearch/reference/6.4/query-dsl-wrapper-query.html
This query is more useful in the context of the Java high-level REST client or transport client to also accept queries as json formatted string. In these cases queries can be specified as a json or yaml formatted string or as a query builder (which is a available in the Java high-level REST client).
GET /_search { "query" : { "wrapper": { "query" : "eyJ0ZXJtIiA6IHsgInVzZXIiIDogIktpbWNoeSIgfX0=" // Base64 encoded string: {"term" : { "user" : "Kimchy" }} } } }
- 将DSL JSON语句 转成 map
https://blog.csdn.net/qq_41370896/article/details/83658948
String dsl = ""; Map maps = (Map)JSON.parse(dsl); maps.get("query");// dsl query string
- Java 代码
https://blog.csdn.net/tcyzhyx/article/details/84566734
https://www.jianshu.com/p/216ca70d9e62
StringBuffer dsl = new StringBuffer(); dsl.append("{\"bool\": {"); dsl.append(" \"must\": ["); dsl.append(" {"); dsl.append(" \"term\": {"); dsl.append(" \"mdid.keyword\": {"); dsl.append(" \"value\": \"2fa9d41e1af460e0d47ce36ca8a98737\""); dsl.append(" }"); dsl.append(" }"); dsl.append(" }"); dsl.append(" ]"); dsl.append(" }"); dsl.append("}"); WrapperQueryBuilder wqb = QueryBuilders.wrapperQuery(dsl.toString()); SearchResponse searchResponse = client.prepareSearch(basicsysCodeManager.getYjzxYjxxIndex()) .setTypes(basicsysCodeManager.getYjzxYjxxType()).setQuery(wqb).setSize(10).get(); SearchHit[] hits = searchResponse.getHits().getHits(); for(SearchHit hit : hits){ String content = hit.getSourceAsString(); System.out.println(content); }
- query + agg 应该怎么写
"{\"query\":{\"match_all\": {}},\"aggs\":{\"avg1\":{\"avg\":{\"field\":\"age\"}}}}"
SearchSourceBuilder ssb = new SearchSourceBuilder(); // add the query part String query ="{\"match_all\": {}}"; WrapperQueryBuilder wrapQB = new WrapperQueryBuilder(query); ssb.query(wrapQB); // add the aggregation part AvgBuilder avgAgg = AggregationBuilders.avg("avg1").field("age"); ssb.aggregation(avgAgg);
实现示例
略
