异常

Exception in thread "main" org.elasticsearch.action.ActionRequestValidationException: Validation Failed: 1: type is missing;
	at org.elasticsearch.action.ValidateActions.addValidationError(ValidateActions.java:26)
	at org.elasticsearch.action.index.IndexRequest.validate(IndexRequest.java:152)
	at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:1728)
	at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:1694)
	at org.elasticsearch.client.RestHighLevelClient.index(RestHighLevelClient.java:926)
	at Elasticsearch05.main(Elasticsearch05.java:41)

代码

向Elasticsearch中插入单条数据：

public class Elasticsearch05 {
    public static void main(String[] args) throws IOException {
        // 传入IP地址和端口号
        HttpHost httpHost = new HttpHost("localhost", 9200, "http");
        // 创建客户端对象
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(httpHost));

        // 1.要在指定索引下创建文档，所以要先创建索引，再创建文档
        IndexRequest request=new IndexRequest();
        // index()方法设置索引名；id()方法设置唯一id标识
        request.index("user").id("10001");
        // 2.创建实体类对象，填充数据
        User user=new User();
        user.setName("张三丰");
        user.setAge(30);
        user.setSex("男");
        // 3.利用jackson将实体类对象转换成JSON格式字符串
        ObjectMapper mapper=new ObjectMapper();
        String userJson = mapper.writeValueAsString(user);
        // 4.添加文档数据，数据格式为JSON格式
        request.source(userJson, XContentType.JSON);
        // 5.发送请求，获取响应结果
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        System.out.println("_index: "+response.getIndex());
        System.out.println("_id: "+response.getId());
        System.out.println("_result: "+response.getResult());

        // 一番操作后，关闭客户端连接
        client.close();
    }
}

原因

代码没有任何问题。

使用高级的client（RestHighLevelClient）是说还要依赖于其他两个jar：

• org.elasticsearch.client:elasticsearch-rest-client
• org.elasticsearch:elasticsearch

而我们在pom.xml导入的elasticsearch依赖是：

        <!-- 使用elasticsearch必须导入的两个包 -->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>6.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>6.6.0</version>
        </dependency>

而实际上应该导入三个坐标，如下：

        <!-- 使用elasticsearch必须导入的三个包 -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-client</artifactId>
            <version>7.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.1.0</version>
        </dependency>

解决

导入elasticsearch、elasticsearch-rest-client、elasticsearch-rest-high-level-client三个的依赖坐标。