标签：json bean 自己 第一个 context ima stc auto 数据操作
1. 简介
RestHighLevelClient是官方指定的Java连接ElasticSearch的API。
需要使用maven引用以下依赖：
<dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-high-level-client</artifactId> <version>6.5.2</version> </dependency>
注意：以上的依赖版本可以根据你使用的ES的版本来定，向下兼容，但是无法向上兼容
2. 创建客户端
创建客户端在网上有很多种配置，下面是最简单的一种，需要其他中详情配置的可以自己查。
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),.........)支持多个httphost连接，也就是支持连接多个elasticsearch restHighLevelClient = new RestHighLevelClient(RestClient.builder(new HttpHost(ip,port))); } static Connection getInstance(){ synchronized (ElasticSearchFactory.class){ if (restHighLevelClient == null){ restHighLevelClient = initClient(); } } return connection; }
注意：以下操作都是个使用了RestHighLevelClient的API对ElasticSearch进行操作，各版本之间的语法可能略有区别。
3. 索引操作
3.1 创建索引
创建索引操作，最简单的操作就是只传一个索引名称，CreateIndexRequest request = new CreateIndexRequest(index); 至于下面组织setting和mappings的XContentBuilder对象，是可以不传，也可以按照自己的业务自行定义。
@Autowired private RestHighLevelClient client;
下面出现的变量client，都是引用的RestHighLevelClient
/** * 创建索引 * @param index 索引名称 * @throws IOException e */ public void createIndex(String index) throws IOException { CreateIndexRequest request = new CreateIndexRequest(index); XContentBuilder builder = JsonXContent.contentBuilder() .startObject() .startObject("settings").field("number_of_shards", 3).field("number_of_replicas", 1).endObject() .startObject("mappings") .startObject("doc") .startObject("properties") .startObject("title").field("type", "text").endObject() .startObject("content").field("type", "text").field("index", true).endObject() .startObject("uniqueId").field("type", "keyword").field("index", false).endObject() .startObject("created").field("type", "date").field("format", "strict_date_optional_time||epoch_millis").endObject() .endObject() .endObject() .endObject() .endObject(); request.source(builder); CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT); System.out.println("createIndex: " + JSONUtil.toJsonStr(createIndexResponse)); }
3.2 查询索引列表
/** * 查询索引列表 * @return Set<String> * @throws IOException e */ public Set<String> indices() throws IOException { GetAliasesRequest request = new GetAliasesRequest(); GetAliasesResponse getAliasesResponse = client.indices().getAlias(request,RequestOptions.DEFAULT); Map<String, Set<AliasMetaData>> aliases = getAliasesResponse.getAliases(); return aliases.keySet(); }
3.3 判断索引存在
/** * 判断索引是否存在，在创建索引之前使用 * @param index 索引名称 * @return boolean * @throws IOException e */ public boolean existsIndex(String index) throws IOException { GetIndexRequest request = new GetIndexRequest(); request.indices(index); return client.indices().exists(request, RequestOptions.DEFAULT); }
4. 数据操作
4.1 新增数据
/** * 新增数据 * @param index 索引 * @param type 索引类型 * @param id 数据ID * @param object 数据对象 */public void addData(String index, String type, String id, JSONObject object) throws IOException { CreateIndexRequest request = new CreateIndexRequest(); client.indices().create(request, RequestOptions.DEFAULT); IndexRequest indexRequest = new IndexRequest(index, type, id); indexRequest.source(JSONUtil.toJsonStr(object), XContentType.JSON); IndexResponse indexResponse = client.index(indexRequest, RequestOptions.DEFAULT); log.info("新增结果: " + JSONUtil.toJsonStr(indexResponse)); }
4.2 判断数据是否存在
/** * 判断数据是否存在 * @param index 索引 * @param type 索引类型 * @param id 数据ID * @return boolean */ public boolean exists(String index, String type, String id) throws IOException { GetRequest getRequest = new GetRequest(index, type, id); getRequest.fetchSourceContext(new FetchSourceContext(false)); getRequest.storedFields("_none_"); boolean exists = client.exists(getRequest, RequestOptions.DEFAULT); log.info("判断数据是否存在：" + exists); return exists; }
4.3 修改数据
/** * 修改数据 * @param index 索引 * @param type 索引类型 * @param id 数据ID * @param object 修改的数据 */ public void updateData(String index, String type, String id, JSONObject object) throws IOException { UpdateRequest request = new UpdateRequest(index, type, id); request.doc(JSONUtil.toJsonStr(object), XContentType.JSON); UpdateResponse updateResponse = client.update(request, RequestOptions.DEFAULT); log.info("修改数据结果: " + JSONUtil.toJsonStr(updateResponse)); }
4.4 删除数据
/** * 删除数据 * @param index 索引 * @param type 索引类型 * @param id 数据ID */ public void deleteData(String index, String type, String id) throws IOException { DeleteRequest deleteRequest = new DeleteRequest(index, type, id); DeleteResponse response = client.delete(deleteRequest, RequestOptions.DEFAULT); System.out.println("删除结果: " + JSONUtil.toJsonStr(response)); }
4.5 批量操作数据
下面的方法是模拟了批量新增、修改、删除，各位可以按照自己的需求修改。
public void bulk(List<UserBean> userList) throws IOException { // 批量增加 BulkRequest bulkAddRequest = new BulkRequest(); for (UserBean user : userList) { IndexRequest indexRequest = new IndexRequest(INDEX_TEST, TYPE_TEST, user.getId().toString()); indexRequest.source(JSONUtil.toJsonStr(user), XContentType.JSON); bulkAddRequest.add(indexRequest); } BulkResponse bulkAddResponse = client.bulk(bulkAddRequest, RequestOptions.DEFAULT); System.out.println("bulkAdd: " + JSONUtil.toJsonStr(bulkAddResponse)); // 批量更新 BulkRequest bulkUpdateRequest = new BulkRequest(); for (UserBean user : userList) { user.setName(user.getName() + " updated"); UpdateRequest updateRequest = new UpdateRequest(INDEX_TEST, TYPE_TEST, user.getId().toString()); updateRequest.doc(JSONUtil.toJsonStr(user), XContentType.JSON); bulkUpdateRequest.add(updateRequest); } BulkResponse bulkUpdateResponse = client.bulk(bulkUpdateRequest, RequestOptions.DEFAULT); System.out.println("bulkUpdate: " + JSONUtil.toJsonStr(bulkUpdateResponse)); // 批量删除 BulkRequest bulkDeleteRequest = new BulkRequest(); for (UserBean user : userList) { DeleteRequest deleteRequest = new DeleteRequest(INDEX_TEST, TYPE_TEST, user.getId().toString()); bulkDeleteRequest.add(deleteRequest); } BulkResponse bulkDeleteResponse = client.bulk(bulkDeleteRequest, RequestOptions.DEFAULT); System.out.println("bulkDelete: " + JSONUtil.toJsonStr(bulkDeleteResponse)); }
5. 数据查询
5.1 关键字查询，匹配单个字段
查询条件都是通过QueryBuilders对象进行创建。
SearchSourceBuilder是用来拼接其他查询参数，比如分页参数，返回的字段值，排序等。
SearchRequest用来指定查询的索引index和type
SearchResponse 是用来接收查询结果，response.getHits().getHits()是查询的数据结果集。
/** * 关键字查询，匹配单个字段 * @param index 索引 * @param type 索引类型 * @param field 查询字段 * @param value 查询参数 * @return String */ public String searchMatch(String index, String type, String field, String value) throws IOException { MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery(field, value); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(matchQueryBuilder); sourceBuilder.from(0); // 查询起始行，分页参数 sourceBuilder.size(100); // 获取记录数，默认10，分页参数 sourceBuilder.fetchSource(new String[] { "id", "name" }, new String[] {}); // 第一个参数是要获取字段，第二个是要过滤的字段，默认获取返回全部字段 sourceBuilder.sort("id", SortOrder.DESC); // 排序 SearchRequest searchRequest = new SearchRequest(index).types(type).source(sourceBuilder); SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT); SearchHits hits = response.getHits(); SearchHit[] searchHits = hits.getHits(); for (SearchHit hit : searchHits) { log.info("查询结果：" + hit.getSourceAsString()); } return JSONUtil.toJsonStr(searchHits); }
5.2 关键字查询，匹配多个字段
/** * 关键字查询，匹配多个字段 * @param index 索引 * @param type 索引类型 * @param fields 查询多个字段 * @param value 查询参数 * @return String */public String searchMultiMatch(String index, String type, List<String> fields, String value) throws IOException { MultiMatchQueryBuilder multiMatchQueryBuilder = QueryBuilders.multiMatchQuery(value, fields.toArray(new String[]{})); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(multiMatchQueryBuilder).from(0).size(100); SearchRequest searchRequest = new SearchRequest(index).types(type).source(sourceBuilder); SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT); ...... }
5.3 关键字查询，范围查询
/** * 关键字查询，范围查询（适用于数字类型、日期类型） * @param index 索引 * @param type 索引类型 * @param field 查询字段 * @param start 开始参数 * @param end 结束参数 */ @Override public String searchRange(String index, String type, String field, int start, int end) throws IOException { RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery(field).from(start).to(end); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(rangeQueryBuilder).from(0).size(100); SearchRequest searchRequest = new SearchRequest(index).types(type).source(sourceBuilder); SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT); ...... }
5.4 关键字精确查询
/** * 关键字精确查询（精确值可能是数字、时间、布尔或者not_analyzed的字符串） * @param index 索引 * @param type 索引类型 * @param field 查询字段 * @param value 查询值 */public String searchTerm(String index, String type, String field, String value) throws IOException { TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery(field, value); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(termQueryBuilder).from(0).size(100); SearchRequest searchRequest = new SearchRequest(index).types(type).source(sourceBuilder); SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT); ...... }
5.5 组合查询
/** * 组合查询 * must 文档 必须 匹配这些条件才能被包含进来。 * must_not 文档 必须不 匹配这些条件才能被包含进来。 * should 如果满足这些语句中的任意语句，将增加 _score ，否则，无任何影响。它们主要用于修正每个文档的相关性得分。 * filter 必须 匹配，但它以不评分、过滤模式来进行。这些语句对评分没有贡献，只是根据过滤标准来排除或包含文档。 * @param index 索引 * @param type 索引类型 * @param field 查询字段 * @param value 查询值 */ public String searchBool(String index, String type, String field, String value) throws IOException { BoolQueryBuilder builder = QueryBuilders.boolQuery(); builder.must(QueryBuilders.matchQuery("title", "我是谁")); builder.mustNot(QueryBuilders.matchQuery("title", "你")); builder.should(QueryBuilders.matchQuery("desc", "啊啊啊")); builder.filter(QueryBuilders.termsQuery("author", "老王")); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(builder).from(0).size(100); SearchRequest searchRequest = new SearchRequest(index).types(type).source(sourceBuilder); SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT); ...... }
6. 聚合
6.1 基础聚合
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); TermsAggregationBuilder categoryAggregationBuilder = AggregationBuilders.terms("byCategory").field("category"); TermsAggregationBuilder sourceAggregationBuilder = AggregationBuilders.terms("bySource").field("source"); sourceBuilder.aggregation(categoryAggregationBuilder).aggregation(sourceAggregationBuilder); SearchRequest searchRequest = new SearchRequest(INDEX_TEST).types(TYPE_TEST).source(sourceBuilder); SearchResponse response = rhlClient.search(searchRequest, RequestOptions.DEFAULT); if (response != null) { ParsedLongTerms resourceTerms = response.getAggregations().get("byCategory"); for (Terms.Bucket entry : resourceTerms.getBuckets()) { System.out.println("统计key=" + entry.getKeyAsString() + "， 统计数量："+ entry.getDocCount()); } } else { log.error("资源状态聚合查询失败：" + searchRequest.toString()); }
ElasticSearch与Java集成-RestHighLevelClient
标签：json bean 自己 第一个 context ima stc auto 数据操作
原文地址：https://www.cnblogs.com/huanshilang/p/14367483.html
