JavaRestClient操作Elasticsearch查询所有(match_all)

青旅半醒 2022-12-23 15:21 145阅读 0赞

# 导包 #

导包可以根据 [文档][Link 1] 里导入依赖  
这里就不写依赖了

# 查询所有 #

import com.google.gson.Gson;
    import com.leyou.pojo.Item;
    import org.apache.http.HttpHost;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.RequestOptions;
    import org.elasticsearch.client.RestClient;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    import java.io.IOException;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest
    public class EsdemofindAll { 
    
        private RestHighLevelClient client;
    
        private Gson gson = new Gson();
        /** * 先执行 */
        @Before
        public void init (){ 
            // 初始化HighLevel客户端
            client = new RestHighLevelClient(
                    RestClient.builder(
                            HttpHost.create("http://127.0.0.1:9201"),
                            HttpHost.create("http://127.0.0.1:9202"),
                            HttpHost.create("http://127.0.0.1:9203")
                    )
            );
        }
    
        /** * 查询全部 */
        @Test
        public void findAll() throws IOException { 
            // 创建搜索对象
            SearchRequest searchRequest = new SearchRequest();
            // 查询构建工具
            SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
            // 添加查询条件，通过QueryBuilders获取各种查询
            searchSourceBuilder.query(QueryBuilders.matchAllQuery());
            searchRequest.source(searchSourceBuilder);
            // 搜索
            SearchResponse search = client.search(searchRequest, RequestOptions.DEFAULT);
            // 解析
            SearchHits hits = search.getHits();
            SearchHit[] hits1 = hits.getHits();
            for (SearchHit hit : hits1) { 
                // 取出source数据
                String itemstring = hit.getSourceAsString();
                // 反序列化
                Item item = gson.fromJson(itemstring, Item.class);
                System.out.println("item ="+item);
            }
        }
    
        /** * 后执行 */
        @After
        public void close(){ 
            try { 
                client.close();
            } catch (IOException e) { 
                e.printStackTrace();
            }
        }
    }

# 打印结果 #

item =Item(id=2, title=坚果手机R1, category=手机, brand=锤子, price=3699.0, images=http://image.csdn.com/13123.jpg)
    item =Item(id=4, title=小米Mix2S, category=手机, brand=小米, price=4299.0, images=http://image.csdn.com/13123.jpg)
    item =Item(id=5, title=荣耀V10, category=手机, brand=华为, price=2799.0, images=http://image.csdn.com/13123.jpg)
    item =Item(id=1, title=小米手机7, category=手机, brand=小米, price=3299.0, images=http://image.csdn.com/13123.jpg)
    item =Item(id=3, title=华为META10, category=手机, brand=华为, price=4499.0, images=http://image.csdn.com/13123.jpg)

[Link 1]: https://blog.csdn.net/weixin_44257023/article/details/110130718