RestHighLevelClient 打印dsl语句

使用RestHighLevelClient执行DSL语句时，可以通过将DSL语句转换为字符串并打印出来来查看生成的DSL查询语句。以下是一个示例代码片段：

import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;

public class ElasticsearchClient {
    private RestHighLevelClient client;

    public ElasticsearchClient() {
        // 初始化RestHighLevelClient
        client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));
    }

    public void printDSLQuery() {
        SearchRequest searchRequest = new SearchRequest("your_index_name");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        
        // 构建DSL查询语句
        searchSourceBuilder.query(QueryBuilders.matchAllQuery());
        
        // 将DSL语句转换为字符串并打印
        String dslQuery = searchSourceBuilder.toString();
        System.out.println("DSL Query: " + dslQuery);
    }
}

在上面的示例中，`printDSLQuery()`方法会初始化一个`RestHighLevelClient`实例，并构建一个DSL查询语句。然后，通过将`SearchSourceBuilder`对象转换为字符串，可以打印生成的DSL查询语句。你可以将`your_index_name`替换为你要执行查询的索引名称。运行代码后，你将在控制台上看到打印出的DSL查询语句。