本文转自SDK社区:sdk.cn
一、创立连贯
!ps:RestHighLevelClient是官网指定的连贯API。另外一个是TransportClient，然而TransportClient这个是曾经废除不必的，所以会在ES8.0之后齐全移除，也就是说8.0之后就无奈应用了
RestHighLevelClient的maven依赖为（应用前必须增加相应依赖）
<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.9.2</version></dependency> <dependency> <groupId>org.elasticsearch</groupId> <artifactId>elasticsearch</artifactId> <version>7.9.2</version></dependency>留神：以上的依赖版本能够依据你应用的ES的版本来定，向下兼容，然而无奈向上兼容
创立连贯
static String ip = "localhost";static int port = 9200;static RestHighLevelClient restHighLevelClient = null;static TransportClient client = null;static RestHighLevelClient initClient(){ //这里的RestClient.builder(new HttpHost(ip,port),.........)反对多个httphost连贯，也就是反对连贯多个elasticsearch restHighLevelClient = new RestHighLevelClient(RestClient.builder(new HttpHost(ip,port)));}static Connection getInstance(){ synchronized (ElasticSearchFactory.class){ if (restHighLevelClient == null){ restHighLevelClient = initClient(); } } return connection;}RestHighLevelClient 反对对ES的增删改查、批量操作
新增：
public static void creatIndex(String json){ IndexRequest indexRequest = new IndexRequest("test_index","String"); indexRequest.source(json, XContentType.JSON);//这里的json为存入ES的文档内容 try { restHighLevelClient.index(indexRequest, RequestOptions.DEFAULT);//RequestOptions在新办法中必须抉择 } catch (IOException e) { e.printStackTrace(); }}查问：
查问反对间接查问和条件查问，因为ES是依据索引、文档类型和文档ID确定一个惟一的文档的，所以间接查问必须要有索引和类型还有ID
public static Map<String, Object> getIndex(String indexName,String type,String id){ GetRequest request = new GetRequest(indexName); //SearchRequest searchRequest = new SearchRequest(indexName); try { GetResponse search = restHighLevelClient.get(request, RequestOptions.DEFAULT); Map<String, Object> source = search.getSource(); return source; } catch (IOException e) { e.printStackTrace(); } return new HashMap<>();}条件查问：
条件查问反对所有的ES的查问规定
public static Map<String, Object> searchIndex(String indexName){ //GetRequest request = new GetRequest(indexName); //SearchRequest searchRequest = new SearchRequest(indexName); QueryBuilder queryBuilders = QueryBuilders.boolQuery().filter( QueryBuilders.termQuery("queryKey","吱吱吱ZZZ") ); SearchRequest searchRequest = new SearchRequest(); //searchRequest.indices("posts");这里能够设计GEET或者POST SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder(); // searchSourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));反对按评分排序，评分是指分词之后获得的文档类似度评分 searchSourceBuilder.query(QueryBuilders.boolQuery().filter(QueryBuilders.termQuery("queryKey.keyword","吱吱吱ZZZ"))); searchRequest.source(searchSourceBuilder); try { SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); SearchHit[] hits = search.getHits().getHits(); for (SearchHit searchHit : hits){ Map<String, Object> sourceAsMap = searchHit.getSourceAsMap(); System.out.println("source : {}" + sourceAsMap.toString()); } } catch (IOException e) { e.printStackTrace(); } return new HashMap<>();}批改：
ps:ES中其实并不存在真正意义上的批改，其实是进行的文档笼罩，先将原文档查出来标记删除，而后在原文档的根底上增加上批改造成一份新文档，存入ES中，之后再将打上删除标记的文档删除。
public static void updateIndex(String indexName, String type, String id, String json){ UpdateRequest request = new UpdateRequest(indexName, type, id); request.doc(json, XContentType.JSON); try { UpdateResponse updateResponse = restHighLevelClient.update(request,RequestOptions.DEFAULT); } catch (IOException e) { e.printStackTrace(); }}删除:
public static void deleteIndex(String indexName, String type, String id){ DeleteRequest request = new DeleteRequest(indexName,type,id); try { restHighLevelClient.delete(request,RequestOptions.DEFAULT); } catch (IOException e) { e.printStackTrace(); }}bulk操作，bulk操作相当于批处理，可能在一次操作中解决一批数据，同时可能同时解决，增删改操作
public static void bulkIndex(){ BulkRequest request = new BulkRequest(); String jsonString="{\n" + "\t\"databaseId\": \"謝謝謝謝謝謝\",\n" + "\t\"databaseType\": \"嘻嘻嘻\",\n" + "\t\"queryKey\":\"吱吱吱ZZZ\"\n" + "}\n"; UUID uuid = UUID.randomUUID(); request.add(new IndexRequest("test_index", "String", uuid.toString()) .source(jsonString,XContentType.JSON)); String updateJson="{\n" + " \"queryKey\":\"吱吱吱ZZZ\"\n" + "}"; request.add(new UpdateRequest("test_index", "String", uuid.toString()) .doc(updateJson,XContentType.JSON)); request.add(new DeleteRequest("test_index", "String", uuid.toString())); try { restHighLevelClient.bulk(request, RequestOptions.DEFAULT); } catch (IOException e) { e.printStackTrace(); }}执行ES-DSL
String json = "{\"bool\":{\"filter\":[{\"term\":{\"queryKey.keyword\":\"吱吱吱ZZZ\"}}]}}";String index= "test_index";public static void wapQuerty(String json,String index){ WrapperQueryBuilder queryBuilder = new WrapperQueryBuilder(json); SearchRequest searchRequest = new SearchRequest(); SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder(); searchSourceBuilder.query(queryBuilder); searchRequest.source(searchSourceBuilder).indices(index); try { SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); SearchHit[] hits = search.getHits().getHits(); for (SearchHit searchHit : hits){ Map<String, Object> sourceAsMap = searchHit.getSourceAsMap(); String id = searchHit.getId(); System.out.println("id:"+id); } } catch (IOException e) { e.printStackTrace(); }}