ElasticSearch之RestClient笔记

左手的ㄟ右手 2024-02-05 19:01 59阅读 0赞

## 1. ElasticSearch ##

![f797b34278bd4e03a7125225e6666534.png][]

### 1.1 倒排索引 ###

![1b24690feb72432eba88b966fdfc31b2.png][]

![8714446210cc4075bcad10c96b45625c.png][]

### 1.2 ElasticSearch和Mysql对比 ###

![8a19fb5d280f4316bd151594efd9b419.png][]

### 1.3 RestClient操作 ###

导入依赖

<dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>elasticsearch-rest-high-level-client</artifactId>
                <version>7.15.0</version>
            </dependency>

并设置

<elasticsearch.version>7.15.0</elasticsearch.version>

添加ElasticSearch配置

@Configuration
    public class ElasticSearchConfig {
        @Bean
        public RestHighLevelClient restHighLevelClient(){
            RestHighLevelClient client=new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1",9200,"http"))
            );
            return client;
        }
    }

索引的创建，判断是否存在，删除

CreateIndexRequest createIndexRequest=new CreateIndexRequest("test");
            restHighLevelClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);
            //判断某个索引库是否存在
            GetIndexRequest getIndexRequest=new GetIndexRequest("test");
            boolean exists = restHighLevelClient.indices().exists(getIndexRequest, RequestOptions.DEFAULT);
            System.out.println(exists);
            //删除某个索引库
            DeleteIndexRequest deleteIndexRequest=new DeleteIndexRequest("test");
            restHighLevelClient.indices().delete(deleteIndexRequest,RequestOptions.DEFAULT);

添加文档

IndexRequest in = new IndexRequest("test").id("1").source("{\n" +
                    "   \"username\":\"admin\",\n" +
                    "   \"password\":\"admin\"\n" +
                    "}", XContentType.JSON);
            restHighLevelClient.index(in,RequestOptions.DEFAULT);

查找文档

GetRequest getRequest=new GetRequest("test","1");
            GetResponse getResponse = restHighLevelClient.get(getRequest, RequestOptions.DEFAULT);
            System.out.println(getResponse.getSourceAsString());

更新文档

//全量更新，再次写入id一样的文档，就会删除旧文档，添加新文档
            IndexRequest in = new IndexRequest("test").id("1").source("{\n" +
                    "   \"username\":\"admin\",\n" +
                    "   \"password\":\"helloworld\"\n" +
                    "}", XContentType.JSON);
            restHighLevelClient.index(in,RequestOptions.DEFAULT);
    
    
    UpdateRequest updateRequest=new UpdateRequest("test","1");
            updateRequest.doc(
                    "password","hello"
            );
            restHighLevelClient.update(updateRequest,RequestOptions.DEFAULT);

删除文档

DeleteRequest deleteRequest=new DeleteRequest("test","1");
            restHighLevelClient.delete(deleteRequest,RequestOptions.DEFAULT);

批量导入文档

BulkRequest bulkRequest=new BulkRequest();
            bulkRequest.add(new IndexRequest("test").id("2").source("{\n" +
                    "   \"username\":\"hello\",\n" +
                    "   \"password\":\"hello\"\n" +
                    "}",XContentType.JSON));
            bulkRequest.add(new IndexRequest("test").id("3").source("{\n" +
                    "   \"username\":\"world\",\n" +
                    "   \"password\":\"world\"\n" +
                    "}",XContentType.JSON));
            restHighLevelClient.bulk(bulkRequest,RequestOptions.DEFAULT);

[f797b34278bd4e03a7125225e6666534.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/03bc7fdb38e94cfb967437aa56271c7d.png
[1b24690feb72432eba88b966fdfc31b2.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/aaa1406d3e9b4bbf8b0617fd90a80ed2.png
[8714446210cc4075bcad10c96b45625c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/e2e3397a8e934f418ec8328842aef996.png
[8a19fb5d280f4316bd151594efd9b419.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/7fc4edad3c5b47c39bffbc1920789bfe.png