Elasticsearch 基本使用

版本以 Elasticsearch 7.x 为主（目前最常用）

一、依赖（Maven）

<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.17.0</version>
</dependency>

二、初始化客户端

RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http"))
);

三、新增文档（Create / Index）

1.普通新增（自动生成 ID）

IndexRequest request = new IndexRequest("user");
request.source(XContentFactory.jsonBuilder().startObject().field("name", "张三").field("age", 25).endObject());IndexResponse response = client.index(request, RequestOptions.DEFAULT);

2.指定 ID 新增

IndexRequest request = new IndexRequest("user").id("1001");
// ... 其他同上

四、查询文档（Get）

 

GetRequest request = new GetRequest("user", "1001");
GetResponse response = client.get(request, RequestOptions.DEFAULT);if (response.isExists()) {String name = response.getSource().get("name").toString();
}

五、更新文档（Update）

1.局部更新

UpdateRequest request = new UpdateRequest("user", "1001");
request.doc(XContentFactory.jsonBuilder().startObject().field("age", 26).endObject());UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

2.upsert（不存在则插入）

request.upsert(XContentFactory.jsonBuilder().startObject().field("name", "张三").field("age", 25).endObject());

六、删除文档（Delete）

DeleteRequest request = new DeleteRequest("user", "1001");
DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);

七、批量操作（Bulk）

 

BulkRequest request = new BulkRequest();request.add(new IndexRequest("user").id("1002").source(XContentFactory.jsonBuilder().startObject().field("name", "李四").endObject()));request.add(new DeleteRequest("user", "1001"));BulkResponse response = client.bulk(request, RequestOptions.DEFAULT);

八、搜索（Search）

1.基本搜索

SearchRequest request = new SearchRequest("user");
SearchSourceBuilder source = new SearchSourceBuilder();// 条件查询
source.query(QueryBuilders.termQuery("name", "张三"));request.source(source);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);for (SearchHit hit : response.getHits()) {Map<String, Object> map = hit.getSourceAsMap();
}

2.分页 + 排序

source.from(0);
source.size(10);
source.sort("age", SortOrder.DESC);

3.多条件 bool 查询

BoolQueryBuilder bool = QueryBuilders.boolQuery();
bool.must(QueryBuilders.termQuery("name", "张三"));
bool.filter(QueryBuilders.rangeQuery("age").gte(20));source.query(bool);

九、关闭客户端

 

client.close();