我想获取到es中返回的全部的hits值，怎么写java代码

要获取ES中返回的全部hits值，您可以使用Java High Level REST Client来编写代码。以下是一个简单的示例代码，可以帮助您实现您的需求：

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.SearchHit;
import org.elasticsearch.search.builder.SearchSourceBuilder;

import java.io.IOException;
import java.util.Arrays;

public class ESUtils {
    public static void getAllHits(RestHighLevelClient client, String index) throws IOException {
        SearchRequest searchRequest = new SearchRequest(index);
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.matchAllQuery());
        searchSourceBuilder.size(1000); // 设置每次查询返回的最大数量
        searchSourceBuilder.timeout(TimeValue.timeValueSeconds(5)); // 设置查询超时时间
        searchRequest.source(searchSourceBuilder);

        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        SearchHit[] searchHits = searchResponse.getHits().getHits();
        Arrays.stream(searchHits).forEach(hit -> {
            System.out.println(hit.getSourceAsString());
        });
    }
}

在这个示例代码中，我们使用match_all查询来获取所有的文档，同时设置每次查询返回的最大数量为1000条，超时时间为5秒。然后，我们通过遍历SearchHit数组来输出每个文档的_source字段。您可以根据实际需求来修改代码。