High Level REST Client

1<dependency>
2    <groupId>org.elasticsearch.client</groupId>
3    <artifactId>elasticsearch-rest-high-level-client</artifactId>
4    <version>7.4.2</version>
5</dependency>
6<dependency>
7    <groupId>org.apache.logging.log4j</groupId>
8    <artifactId>log4j-core</artifactId>
9    <version>2.7</version>
10</dependency>
11<dependency>
12    <groupId>org.apache.logging.log4j</groupId>
13    <artifactId>log4j-api</artifactId>
14    <version>2.7</version>
15</dependency>

1import java.io.IOException;
2import org.apache.http.HttpHost;
3import org.apache.http.auth.AuthScope;
4import org.apache.http.auth.UsernamePasswordCredentials;
5import org.apache.http.client.CredentialsProvider;
6import org.apache.http.impl.client.BasicCredentialsProvider;
7import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
8import org.elasticsearch.action.ActionListener;
9import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
10import org.elasticsearch.action.delete.DeleteRequest;
11import org.elasticsearch.action.delete.DeleteResponse;
12import org.elasticsearch.action.index.IndexRequest;
13import org.elasticsearch.action.index.IndexResponse;
14import org.elasticsearch.action.support.master.AcknowledgedResponse;
15import org.elasticsearch.client.RequestOptions;
16import org.elasticsearch.client.RestClient;
17import org.elasticsearch.client.RestClientBuilder;
18import org.elasticsearch.client.RestHighLevelClient;
19import org.elasticsearch.client.indices.CreateIndexRequest;
20import org.elasticsearch.client.indices.CreateIndexResponse;
21import org.elasticsearch.common.settings.Settings;
22import org.elasticsearch.common.xcontent.XContentBuilder;
23import org.elasticsearch.common.xcontent.XContentFactory;
24import org.elasticsearch.common.xcontent.XContentType;
25
26public class RestClientTest742 {
27
28    public static void main(String[] args) {
29        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
30        //访问用户名和密码为您创建Elasticsearch实例时设置的用户名和密码。
31        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("{访问用户名}", "{访问密码}"));
32        // 通过builder创建rest client，配置http client的HttpClientConfigCallback。
33        // ES HTTP URL 在Baidu Elasticsearch界面中可以查询
34        RestClientBuilder builder = RestClient.builder(new HttpHost("{ES HTTP URL}", 8200))
35                .setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
36                    @Override
37                    public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
38                        return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
39                    }
40                });
41
42        // RestHighLevelClient实例通过REST low-level client builder进行构造。
43        RestHighLevelClient client = new RestHighLevelClient(builder);
44
45        try {
46            //创建索引
47            CreateIndexRequest createRequest = new CreateIndexRequest("my_index");
48
49            //创建的每个索引都可以有与之关联的特定设置。
50            createRequest.settings(Settings.builder()
51                    .put("index.number_of_shards", 3)
52                    .put("index.number_of_replicas", 1)
53                    .put("index. refresh_interval", "10s")
54            );
55            // 创建索引时创建文档类型映射
56            createRequest.mapping("{\n" +
57                            "    \"message\": {\n" +
58                            "      \"properties\": {\n" +
59                            "        \"message\": {\n" +
60                            "          \"type\": \"text\"\n" +
61                            "        }\n" +
62                            "      }\n" +
63                            "    }\n" +
64                            "  }",
65                    XContentType.JSON);
66            // 同步执行创建索引操作
67            CreateIndexResponse createIndexResponse = client.indices().create(createRequest, RequestOptions.DEFAULT);
68            System.out.println("create index successfully! response : " + createIndexResponse.toString());
69
70            // 写入文档
71            // 以XContentBuilder对象的形式提供，Elasticsearch 内部会帮我们生成JSON内容
72            XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();
73            jsonBuilder.startObject();
74            {
75                jsonBuilder.field("user", "Kobe Bryant");
76                jsonBuilder.field("number", 24);
77                jsonBuilder.field("message", "One of the greatest basketball players since the 21st century");
78            }
79            jsonBuilder.endObject();
80            IndexRequest indexRequest = new IndexRequest("my_index").id("1").source(jsonBuilder);
81            //异步执行写入文档操作，方法不会阻塞并立即返回。
82            ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
83                @Override
84                public void onResponse(IndexResponse indexResponse) {
85                    //执行成功时调用。 Response以参数方式提供
86                    System.out.println("Index doc successfully! response : " + indexResponse.toString());
87                }
88
89                @Override
90                public void onFailure(Exception e) {
91                    //在失败的情况下调用。 引发的异常以参数方式提供
92                    System.out.println("Index doc fail!");
93                    e.printStackTrace();
94                }
95            };
96            //异步执行索引请求需要将IndexRequest实例和ActionListener实例传递给异步方法：
97            client.indexAsync(indexRequest, RequestOptions.DEFAULT, listener);
98
99            // 删除文档
100            DeleteRequest deleteRequest = new DeleteRequest("my_index").id("1");
101            // 执行删除文档操作
102            DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
103            System.out.println("Delete doc successfully! \n" + deleteResponse.toString() + "\n" + deleteResponse.status());
104
105            // 指定要删除的索引名称
106            DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("my_index");
107            // 执行删除索引操作
108            AcknowledgedResponse deleteIndexResponse = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);
109            System.out.println("delete index successfully! response : " + deleteIndexResponse.toString());
110        } catch (IOException ioException) {
111            // 异常处理。
112            ioException.printStackTrace();
113        } finally {
114            // 在不需要使用client后，将client关闭。
115            try {
116                client.close();
117            } catch (IOException e) {
118                e.printStackTrace();
119            }
120        }
121    }
122}