Elasticsearch Java REST高级客户端SearchScrollApi-蒲公英云

Elasticsearch Java REST高级客户端SearchScrollApi

版本：Elasticsearch 7.2.0

maven配置见：Elasticsearch Java REST高级客户端-DocumentApi

SearchScroll和search的使用时是很相似的，只是在search上多了个滚动

对人工智能感兴趣的同学，可以点击以下链接：

现在人工智能非常火爆，很多朋友都想学，但是一般的教程都是为博硕生准备的，太难看懂了。最近发现了一个非常适合小白入门的教程，不仅通俗易懂而且还很风趣幽默。所以忍不住分享一下给大家。点这里可以跳转到教程。

https://www.cbedai.net/u014646662

下面是Elasticsearch 滚动查询（或是分页查询）

public static void searchScroll() {
        RestHighLevelClient client = getClient();
        final Scroll scroll = new Scroll(TimeValue.timeValueMinutes(1L));
        SearchRequest searchRequest = new SearchRequest("movies");
        searchRequest.scroll(scroll);
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "you life");
        searchSourceBuilder.query(matchQueryBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = null;
        try {
            searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        } catch (IOException e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        String scrollId = searchResponse.getScrollId();
        SearchHit[] searchHits = searchResponse.getHits().getHits();
        var page = 1;
        while (searchHits != null && searchHits.length > 0) {
            SearchScrollRequest scrollRequest = new SearchScrollRequest(scrollId);
            scrollRequest.scroll(scroll);
            try {
                searchResponse = client.scroll(scrollRequest, RequestOptions.DEFAULT);
            } catch (IOException e) {
                e.printStackTrace();
            }
            scrollId = searchResponse.getScrollId();
            searchHits = searchResponse.getHits().getHits();
            if (searchHits != null && searchHits.length > 0) {
                page++;
                System.out.println("第"+page+"页");
                Arrays.asList(searchHits).stream().map(h -> h.getSourceAsString()).forEach(System.out::println);
            }
        }
        ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
        clearScrollRequest.addScrollId(scrollId);
        ClearScrollResponse clearScrollResponse;
        try {
            clearScrollResponse = client.clearScroll(clearScrollRequest, RequestOptions.DEFAULT);
            boolean succeeded = clearScrollResponse.isSucceeded();
            System.out.println("清除滚屏是否成功:" + succeeded);
        } catch (IOException e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        close(client);
    }
    /**
     * 
     * 关闭客户端
     * 
     * @param client
     */
    private static void close(RestHighLevelClient client) {
        try {
            client.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    /**
     * 获取客户端
     * 
     * @return
     */
    private static RestHighLevelClient getClient() {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("elk-node01", 9200, "http"), new HttpHost("elk-node02", 9200, "http"),
                        new HttpHost("elk-node03", 9200, "http")));
        return client;
    }