一、基础操作：创建和关闭es服务器

? ? ? ? 1、创建maven项目，并导入依赖?

<dependencies>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch的客户端 -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch依赖2.x的log4j -->
        <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>
        <!-- junit单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>

? ? ? ? 2、java代码?

public class ESTest_Client {
    public static void main(String[] args) throws IOException {

        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http"))
        );

        //关闭ES客户端
        esClient.close();
    }
}

二、索引操作

? ? ? ? 1、创建索引?

public class ESTest_Index_Create {
    public static void main(String[] args) throws IOException {

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

        CreateIndexRequest request = new CreateIndexRequest("user");
        CreateIndexResponse createIndexResponse = esClient.indices().create(request, RequestOptions.DEFAULT);

        //看一下结果是不是成功了
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("索引操作：" + acknowledged);

        esClient.close();
    }
}

? ? ? ? 2、查询索引?

public class ESTest_Index_Search {
    public static void main(String[] args) throws IOException {

        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http"))
        );

        GetIndexRequest getIndexRequest = new GetIndexRequest("user");
        GetIndexResponse getIndexResponse = esClient.indices().get(getIndexRequest, RequestOptions.DEFAULT);

        //响应状态
        System.out.println(getIndexResponse.getAliases());
        System.out.println(getIndexResponse.getMappings());
        System.out.println(getIndexResponse.getIndices());

        //关闭ES客户端
        esClient.close();
    }
}

? ? ? ? 3、删除索引?

public class ESTest_Index_Delete {
    public static void main(String[] args) throws IOException {

        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http"))
        );

        DeleteIndexRequest request = new DeleteIndexRequest("user");
        AcknowledgedResponse response = esClient.indices().delete(request, RequestOptions.DEFAULT);

        //响应状态
        System.out.println(response.isAcknowledged());

        //关闭ES客户端
        esClient.close();
    }
}