Elasticsearch 781 java操作es实现增删改查代码

以下示例代码演示了如何使用Java API实现Elasticsearch的增删改查操作。

注意：以下示例代码仅供参考，实际使用时需要根据具体需求进行修改和优化。

添加依赖

在pom.xml文件中添加以下依赖：

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.8.1</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>7.8.1</version>
</dependency>

创建Elasticsearch客户端

使用RestHighLevelClient创建Elasticsearch客户端：

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

添加文档

以下示例代码演示了如何添加一条文档到Elasticsearch：

IndexRequest request = new IndexRequest("index_name");
request.id("document_id");
String jsonString = "{" +
        "\"user\":\"kimchy\"," +
        "\"postDate\":\"2021-01-01\"," +
        "\"message\":\"trying out Elasticsearch\"" +
        "}";
request.source(jsonString, XContentType.JSON);
IndexResponse response = client.index(request, RequestOptions.DEFAULT);

获取文档

以下示例代码演示了如何获取一条文档：

GetRequest getRequest = new GetRequest("index_name", "document_id");
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
String sourceAsString = getResponse.getSourceAsString();
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();

更新文档

以下示例代码演示了如何更新一条文档：

UpdateRequest request = new UpdateRequest("index_name", "document_id");
String jsonString = "{" +
        "\"updated_field\":\"updated_value\"" +
        "}";
request.doc(jsonString, XContentType.JSON);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

删除文档

以下示例代码演示了如何删除一条文档：

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

关闭客户端

使用完Elasticsearch客户端后，需要关闭它：

client.close();
``