ES基本操作（JavaAPI篇）-编程知识

引入jar包依赖

    <dependencies><dependency><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId><version>7.8.0</version></dependency><!-- es客户端 --><dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.8.0</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>2.8.2</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.8.2</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.9.9</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency></dependencies>

调用API创建Index

查询和删除Index

        GetIndexRequest request = new GetIndexRequest("user");GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);System.out.println("Aliases = " + response.getAliases());System.out.println("Mappings = " + response.getMappings());// 删除DeleteIndexRequest deleteRequest = new DeleteIndexRequest("user");AcknowledgedResponse deleteResp = client.indices().delete(deleteRequest, RequestOptions.DEFAULT);System.out.println("deleteResp = " + deleteResp.toString());

创建和修改文档

User user = new User();
user.setName("刘德华");
user.setAge(60L);
user.setSex("男");
IndexRequest request = new IndexRequest();
request.index("user").id("1");
// 插入es需要转成json格式
request.source(JSON.toJSONString(user), XContentType.JSON);
IndexResponse index = client.index(request, RequestOptions.DEFAULT);// 修改
UpdateRequest updateRequest = new UpdateRequest();
updateRequest.index("user").id("1");
updateRequest.doc(XContentType.JSON, "age", 65L);
UpdateResponse updateResponse = client.update(updateRequest, RequestOptions.DEFAULT);System.out.println(updateResponse.getResult());

查询文档和删除

// 查询
GetRequest request = new GetRequest();
request.index("user").id("1");
GetResponse documentFields = client.get(request, RequestOptions.DEFAULT);
System.out.println(documentFields.getSource());// 删除
DeleteRequest deleteRequest = new DeleteRequest();
deleteRequest.index("user").id("1");
DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
System.out.println(deleteResponse.getResult());

批量新增和删除

        BulkRequest bulkRequest = new BulkRequest();bulkRequest.add(new IndexRequest().index("user").id("2").source(JSON.toJSONString(new User("梁朝伟", "男", 62L)), XContentType.JSON));bulkRequest.add(new IndexRequest().index("user").id("3").source(JSON.toJSONString(new User("黎明", "男", 58L)), XContentType.JSON));bulkRequest.add(new IndexRequest().index("user").id("4").source(JSON.toJSONString(new User("郭富城", "男", 55L)),XContentType.JSON));bulkRequest.add(new IndexRequest().index("user").id("5").source(JSON.toJSONString(new User("刘亦菲", "女", 28L)), XContentType.JSON));BulkResponse bulkResponse = client.bulk(bulkRequest, RequestOptions.DEFAULT);// 批量删除BulkRequest bulkRequest = new BulkRequest();bulkRequest.add(new DeleteRequest().index("user").id("2"));bulkRequest.add(new DeleteRequest().index("user").id("3"));bulkRequest.add(new DeleteRequest().index("user").id("4"));bulkRequest.add(new DeleteRequest().index("user").id("5"));BulkResponse response = client.bulk(bulkRequest, RequestOptions.DEFAULT);

全量查询

        SearchRequest searchRequest = new SearchRequest();searchRequest.indices("user").source(new SearchSourceBuilder().query(QueryBuilders.matchAllQuery()));SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);for (SearchHit hit : searchResponse.getHits()) {System.out.println(hit.getSourceAsString());}

对于其他的查询，需要修改“QueryBuilders.matchAllQuery()”

条件查询、排序、分页、指定查询字段

        SearchRequest searchRequest = new SearchRequest();searchRequest.indices("user");// 排除的字段String[] excludes = {};// 查询的字段String[] includes = {"name"};searchRequest.source(new SearchSourceBuilder()// 条件查询.query(QueryBuilders.termQuery("sex", "男"))// 指定查询的字段.fetchSource(includes, excludes)// 排序.sort("age", SortOrder.DESC)// 分页.from(0).size(2));SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);for (SearchHit hit : searchResponse.getHits()) {System.out.println(hit.getSourceAsString());}

组合查询、高亮显示

注意：中文自动分词，可模糊搜索。如：

must(QueryBuilders.matchQuery("name", "亦菲"))

        SearchRequest searchRequest = new SearchRequest();searchRequest.indices("user");searchRequest.source(new SearchSourceBuilder().query(QueryBuilders.boolQuery()// and条件//.must(QueryBuilders.matchQuery("age", 28))//.must(QueryBuilders.matchQuery("sex", "女"))//.must(QueryBuilders.matchQuery("name", "亦菲"))// or条件.should(QueryBuilders.matchQuery("age", 28)).should(QueryBuilders.matchQuery("age", 58))).highlighter(new HighlightBuilder().preTags("<font color='red'>").postTags("</font>").field("name")));SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);for (SearchHit hit : searchResponse.getHits()) {System.out.println(hit.getSourceAsString());}

范围查询

        SearchRequest searchRequest = new SearchRequest();searchRequest.indices("user");searchRequest.source(new SearchSourceBuilder().query(QueryBuilders.rangeQuery("age").gte(18).lt(30)));SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);for (SearchHit hit : searchResponse.getHits()) {System.out.println(hit.getSourceAsString());}

聚合查询

        // 聚合查询SearchRequest searchRequest = new SearchRequest();searchRequest.indices("user");searchRequest.source(new SearchSourceBuilder().aggregation(// 最小值//AggregationBuilders.min("minAge").field("age")// 分组统计AggregationBuilders.terms("ageGroup").field("age")));SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);