如何在 Elastic 高级 REST 客户端中使用search_after进行分页

Question

我正在使用弹性 RestHighLevelClient 与 ES 通信。我能够查询基本查询。尽管我正在尝试使用 search_after API 从我的前端查询设计分页 API。虽然query_after在 RestLowLevelClient API 中使用起来很简单，但我无法弄清楚如何在 HighLevel API 中使用它。

看起来lucene api有SearchAfterSortedDocQuery，但我无法弄清楚如何将其与弹性搜索API一起使用。例如：在下面的代码中，我初始化了SearchAfterSortedDocQuery查询，但不确定如何使用它。

RestHighLevelClient client = ESRestClient.getClient();
SearchRequest searchRequest = new SearchRequest();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.termQuery("field1",value1));
searchSourceBuilder.query(QueryBuilders.termQuery("field2",value2));
searchSourceBuilder.from(0);
searchSourceBuilder.size(limit);
SortField[] sortFields = new SortField[2];
sortFields[0]= new SortField("field1", SortField.Type.LONG);
sortFields[1]= new SortField("field2", SortField.Type.LONG);

FieldDoc fieldDoc = new FieldDoc(0,0); //Is this correct? how to initialize field doc?
fieldDoc.fields = new Object[2];
fieldDoc.fields[0] = new Long("-156034");
fieldDoc.fields[1] = new Long("2297416849");
SearchAfterSortedDocQuery query = new SearchAfterSortedDocQuery(new Sort(sortFields), fieldDoc);
searchRequest.source(searchSourceBuilder);
searchRequest.indices("index1");
try {
SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
System.out.println(response);
}
catch(IOException e){
System.out.println(e);
}
}

Answer 1

我认为与其使用SearchAfterSortedDocQuery，不如在searchSourceBuilder中设置search_after

如下所示

searchSourceBuilder.searchAfter(new Object[]{sortAfterValue});

之后使用搜索请求和休息客户端获取响应

SearchRequest searchRequest = new SearchRequest("index");
searchRequest.types("type");
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT)
SearchHits hits = searchResponse.getHits();

最后，您应该保留 getSortValues(( 的最后一个排序值以转到下一页。

hits.getAt(lastIndex).getSortValues()

Elasticsearch search_after API

希望这有帮助。