Elasticsearch入门之（三）使用java进行增删改查

朱雀 2020-10-25 08:33 757阅读 0赞

一、引入Elasticsearch的jar包，版本和安装的版本一致

<dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.9.0</version>
    </dependency>
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.9.0</version>
    </dependency>

二、创建工具类

package springboot.elasticsearch;
    
    import com.alibaba.fastjson.JSONObject;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import org.apache.http.HttpHost;
    import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
    import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
    import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
    import org.elasticsearch.action.delete.DeleteRequest;
    import org.elasticsearch.action.get.GetRequest;
    import org.elasticsearch.action.get.GetResponse;
    import org.elasticsearch.action.index.IndexRequest;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.action.update.UpdateRequest;
    import org.elasticsearch.client.RequestOptions;
    import org.elasticsearch.client.RestClient;
    import org.elasticsearch.client.RestClientBuilder;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.xcontent.XContentType;
    import org.elasticsearch.index.query.BoolQueryBuilder;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import java.io.IOException;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Map;
    
    public class ElasticsearchUtil {
    	private static final Logger LOGGER = LoggerFactory.getLogger(ElasticsearchUtil.class);
    
    	private static RestHighLevelClient client;
    
    	private static ObjectMapper mapper = new ObjectMapper();
    
    	static {
    		RestClientBuilder lowLevelRestClient = RestClient.builder(new HttpHost("192.168.10.77", 9200, "http"));
    		client = new RestHighLevelClient(lowLevelRestClient);
    	}
    
    	/**
    	 * 关闭客户端
    	 */
    	public static void close() {
    		try {
    			client.close();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 创建索引
    	 * @param index
    	 * @return
    	 */
    	public static boolean createIndex(String index) throws IOException {
    		//index名必须全小写，否则报错
    		CreateIndexRequest request = new CreateIndexRequest(index);
    		CreateIndexResponse indexResponse = client.indices().create(request,RequestOptions.DEFAULT);
    		if (indexResponse.isAcknowledged()) {
    			LOGGER.info("创建索引成功");
    		} else {
    			LOGGER.info("创建索引失败");
    		}
    		return indexResponse.isAcknowledged();
    	}
    
    	/**
    	 * 检查索引
    	 * @param index
    	 * @return
    	 * @throws IOException
    	 */
    	public static boolean checkIndexExist(String index) throws IOException {
    		GetIndexRequest request = new GetIndexRequest();
    		request.indices(index);
    		boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
    		return exists;
    	}
    
    	/**
    	 * 获取低水平客户端
    	 * @return
    	 */
    	public static RestClient getLowLevelClient() {
    		return client.getLowLevelClient();
    	}
    
    	/**
    	 * 获取记录信息
    	 * @param index
    	 * @param type
    	 * @param id
    	 * @throws IOException
    	 */
    	public static Map<String, Object> getJson(String index, String type, String id) throws IOException {
    		GetRequest getRequest = new GetRequest(index, type,id);
    		GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
    		return getResponse.getSource();
    	}
    
    	/**
    	 * 插入记录信息
    	 * @param index
    	 * @param type
    	 * @param object
    	 */
    	public static void insert(String index,String type,String id,JSONObject object) throws IOException {
    		IndexRequest indexRequest = new IndexRequest(index, type, id);
    		indexRequest.source(mapper.writeValueAsString(object), XContentType.JSON);
    		client.index(indexRequest,RequestOptions.DEFAULT);
    	}
    
    	/**
    	 * 更新记录信息
    	 * @param index
    	 * @param type
    	 * @param id
    	 * @param object
    	 * @throws IOException
    	 */
    	public static void update(String index, String type, String id, JSONObject object) throws IOException {
    		UpdateRequest request = new UpdateRequest(index, type, id);
    		request.doc(object, XContentType.JSON);
    		client.update(request, RequestOptions.DEFAULT);
    	}
    
    	/**
    	 * 删除记录
    	 * @param index
    	 * @param type
    	 * @param id
    	 * @throws IOException
    	 */
    	public static void delete(String index, String type, String id) throws IOException {
    		DeleteRequest deleteRequest = new DeleteRequest(index, type, id);
    		client.delete(deleteRequest, RequestOptions.DEFAULT);
    	}
    
    	/**
    	 * 搜索
    	 * @param index
    	 * @param type
    	 * @param name
    	 * @throws IOException
    	 */
    	public static List<String> search(String index, String type, String name) throws IOException {
    		BoolQueryBuilder boolBuilder = QueryBuilders.boolQuery();
    		boolBuilder.must(QueryBuilders.matchQuery("content", name)); // 这里可以根据字段进行搜索，must表示符合条件的，相反的mustnot表示不符合条件的
    //		boolBuilder.must(QueryBuilders.multiMatchQuery("content","title", name)); // 这里可以根据多个字段进行搜索，must表示符合条件的，相反的mustnot表示不符合条件的
    		SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    		sourceBuilder.query(boolBuilder);
    		sourceBuilder.from(0);
    		sourceBuilder.size(100); // 获取记录数，默认10
    		sourceBuilder.fetchSource(new String[] { "id", "content" }, new String[] {}); // 第一个是获取字段，第二个是过滤的字段，默认获取全部
    		SearchRequest searchRequest = new SearchRequest(index);
    		searchRequest.types(type);
    		searchRequest.source(sourceBuilder);
    		SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
    		List<String> list = new LinkedList<>();
    		SearchHits hits = response.getHits();
    		SearchHit[] searchHits = hits.getHits();
    		for (SearchHit hit : searchHits) {
    			String id = hit.getId();
    //			list.add(hit.getSourceAsString());
    			list.add(id);
    		}
    		return list;
    	}
    
    }

三、测试方法

String jsonObj = "{" +
    		"\"file_name\":\"我是file_name\"," +
    		"\"time\":\"2020-08-30 16:35:34\"," +
    		"\"content\":\"cs内容\"" +
    		"}";
    ElasticsearchUtil.insert("cs", "doc", "1", JSON.parseObject(jsonObj));
    //ElasticsearchUtil.update("cs", "doc", "3", JSON.parseObject(jsonObj));
    //ElasticsearchUtil.delete("cs", "doc", "2");
    Map<String, Object> source = ElasticsearchUtil.getJson("cs", "doc", "3");
    System.out.println(source.get("content"));
    List<String> list = ElasticsearchUtil.search("cs", "doc", "cs");