"aggs": { "top_fields_agg": { "top_hits": { "sort": [ { "date": { "order": "desc" } } ], "_source": { "includes": [ "company_name", "state", "date" ] }, "size": 1 } } }如何转换成java的写法

你可以使用 Elasticsearch Java API 来实现这个聚合查询的写法。具体代码如下：

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.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.tophits.TopHitsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;

import java.io.IOException;

public class ElasticsearchAggregationExample {

    public static void main(String[] args) throws IOException {

        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));

        SearchRequest searchRequest = new SearchRequest("your_index_name");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.matchAllQuery());

        TopHitsAggregationBuilder topFieldsAgg = AggregationBuilders.topHits("top_fields_agg")
                .sort("date", SortOrder.DESC)
                .fetchSource(new String[]{"company_name", "state", "date"}, null)
                .size(1);

        searchSourceBuilder.aggregation(topFieldsAgg);

        searchRequest.source(searchSourceBuilder);
        searchRequest.scroll(TimeValue.timeValueMinutes(1L));

        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

        // process search response here

        client.close();
    }
}

注意，你需要将 `your_index_name` 替换为你要查询的索引名称。同时，你需要为查询设置适当的查询条件，例如在上面的例子中，我们使用了 `QueryBuilders.matchAllQuery()`，表示查询所有的文档。在实际使用中，你可以根据自己的需求设置不同的查询条件。最后，你需要对查询结果进行相应的处理。