Java Low Level REST Client
更新時(shí)間：
Java Low Level REST Client是Elasticsearch官方提供的低級(jí)別REST客戶端，其API不負(fù)責(zé)數(shù)據(jù)的編碼與解碼。Lindorm搜索引擎兼容Elasticsearch 7.10及更早版本的功能，如果您想要自定義請(qǐng)求和響應(yīng)處理方式，可以通過(guò)Java Low Level REST Client連接并使用搜索引擎。
前提條件
已安裝Java環(huán)境，要求安裝JDK 1.8及以上版本。
已開(kāi)通搜索引擎。如何開(kāi)通，請(qǐng)參見(jiàn)開(kāi)通指南。
已將客戶端IP地址添加至Lindorm白名單，具體操作請(qǐng)參見(jiàn)設(shè)置白名單。
操作步驟
安裝Low Level Rest Client。以Maven項(xiàng)目為例，在
pom.xml文件的dependencies中添加依賴項(xiàng)。示例代碼如下：<dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-client</artifactId> <version>7.10.0</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.8.2</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.7</version> </dependency>配置連接參數(shù)。
//Lindorm搜索引擎的Elasticsearch兼容地址 String search_url = "ld-t4n5668xk31ui****-proxy-search-public.lindorm.rds.aliyuncs.com"; int search_port = 30070; // 配置用戶名密碼 String username = "user"; String password = "test"; final CredentialsProvider credentialsProvider = new BasicCredentialsProvider(); credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password)); RestClientBuilder restClientBuilder = RestClient.builder(new HttpHost(search_url, search_port)); restClientBuilder.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() { @Override public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) { return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider); } });參數(shù)說(shuō)明
參數(shù)
說(shuō)明
search_url
Lindorm搜索引擎的Elasticsearch兼容地址。如何獲取，請(qǐng)參見(jiàn)查看連接地址。
重要如果應(yīng)用部署在ECS實(shí)例，建議您通過(guò)專有網(wǎng)絡(luò)訪問(wèn)Lindorm實(shí)例，可獲得更高的安全性和更低的網(wǎng)絡(luò)延遲。
如果應(yīng)用部署在本地，在通過(guò)公網(wǎng)連接Lindorm實(shí)例前，需在控制臺(tái)開(kāi)通公網(wǎng)地址。開(kāi)通方式：在控制臺(tái)的左側(cè)導(dǎo)航欄，選擇數(shù)據(jù)庫(kù)連接，單擊搜索引擎頁(yè)簽，在頁(yè)簽右上角單擊開(kāi)通公網(wǎng)地址。
通過(guò)專有網(wǎng)絡(luò)訪問(wèn)Lindorm實(shí)例，search_url請(qǐng)?zhí)顚慐lasticsearch兼容地址對(duì)應(yīng)的專有網(wǎng)絡(luò)地址。通過(guò)公網(wǎng)訪問(wèn)Lindorm實(shí)例，search_url請(qǐng)?zhí)顚慐lasticsearch兼容地址對(duì)應(yīng)的公網(wǎng)地址。
search_port
Lindorm搜索引擎Elasticsearch兼容的端口，固定為30070。
username
訪問(wèn)搜索引擎的用戶名和密碼。
默認(rèn)用戶名和密碼的獲取方式：在控制臺(tái)的左側(cè)導(dǎo)航欄，選擇數(shù)據(jù)庫(kù)連接，單擊搜索引擎頁(yè)簽，在搜索引擎頁(yè)簽可獲取。
password
使用Java Low Level REST Client對(duì)象訪問(wèn)搜索引擎。
示例代碼分為以下幾部分：
創(chuàng)建搜索索引：創(chuàng)建搜索索引lindorm_index。
數(shù)據(jù)寫入：使用批量數(shù)據(jù)寫入的方式，寫入5000條文檔。
數(shù)據(jù)查詢：刷新請(qǐng)求，強(qiáng)制寫入的數(shù)據(jù)可見(jiàn)。執(zhí)行兩個(gè)請(qǐng)求，分別查詢索引中的全部文檔和ID為特定值的文檔。
數(shù)據(jù)刪除：刪除ID為test的文檔，并刪除索引lindorm_index。
try (RestClient restClient = restClientBuilder.build()) { String indexName = "lindorm_index"; // 創(chuàng)建索引 Request indexRequest = new Request("PUT", "/" + indexName); indexRequest.setJsonEntity("{" + " \"settings\":{" + " \"index.number_of_shards\": 1" + " }," + " \"mappings\":{" + " \"properties\":{" + " \"name\":{" + " \"type\":\"text\"" + " }" + " }" + " }" + "}"); Response response = restClient.performRequest(indexRequest); String responseBody = EntityUtils.toString(response.getEntity()); System.out.println("responseBody = " + responseBody); // 批量寫入數(shù)據(jù) Random random = new Random(); Request bulkRequest = new Request("POST", "/_bulk"); StringBuilder bulkJsonBuilder = new StringBuilder(); for (int i = 0; i < 5000; i++) { // 請(qǐng)將field和value替換為實(shí)際業(yè)務(wù)字段與值 bulkJsonBuilder.append("{\"index\":{\"_index\":\"").append(indexName).append("\",\"_id\":\"").append(i).append("\"}}").append("\n"); String value = random.nextInt() + ""; bulkJsonBuilder.append("{\"field1\":\"").append(value).append("\",\"field2\":\"").append(value).append("\"}").append("\n"); } bulkRequest.setJsonEntity(bulkJsonBuilder.toString()); response = restClient.performRequest(bulkRequest); // 發(fā)送刷新請(qǐng)求，強(qiáng)制已寫數(shù)據(jù)可見(jiàn) response = restClient.performRequest(new Request("POST", "/" + indexName + "/_refresh")); responseBody = EntityUtils.toString(response.getEntity()); System.out.println("responseBody = " + responseBody); // 查詢索引中所有數(shù)據(jù)，默認(rèn)最多返回10條查詢結(jié)果 response = restClient.performRequest(new Request("GET", "/" + indexName + "/_search")); responseBody = EntityUtils.toString(response.getEntity()); System.out.println("responseBody = " + responseBody); // 查詢索引中文檔id為"0"的數(shù)據(jù) response = restClient.performRequest(new Request("GET", "/" + indexName + "/_doc/0")); responseBody = EntityUtils.toString(response.getEntity()); System.out.println("responseBody = " + responseBody); // 刪除索引 response = restClient.performRequest(new Request("DELETE", "/" + indexName)); responseBody = EntityUtils.toString(response.getEntity()); System.out.println("responseBody = " + responseBody); } catch (Exception e) { System.out.println("msg: " + e.getMessage()); }
完整示例
完整示例代碼如下：
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.apache.http.util.EntityUtils;
import org.elasticsearch.client.Request;
import org.elasticsearch.client.Response;
import java.util.Random;
public class RestLClientTest {
public static void main(String[] args) {
// Lindorm搜索引擎的Elasticsearch兼容地址
String search_url = "ld-t4n5668xk31ui****-proxy-search-public.lindorm.rds.aliyuncs.com";
int search_port = 30070;
// 配置用戶名密碼
String username = "user";
String password = "test";
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));
RestClientBuilder restClientBuilder = RestClient.builder(new HttpHost(search_url, search_port));
restClientBuilder.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
@Override
public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
}
});
try (RestClient restClient = restClientBuilder.build()) {
String indexName = "lindorm_index";
// 創(chuàng)建索引
Request indexRequest = new Request("PUT", "/" + indexName);
indexRequest.setJsonEntity("{" +
" \"settings\":{" +
" \"index.number_of_shards\": 1" +
" }," +
" \"mappings\":{" +
" \"properties\":{" +
" \"name\":{" +
" \"type\":\"text\"" +
" }" +
" }" +
" }" +
"}");
Response response = restClient.performRequest(indexRequest);
String responseBody = EntityUtils.toString(response.getEntity());
System.out.println("responseBody = " + responseBody);
// 批量寫入數(shù)據(jù)
Random random = new Random();
Request bulkRequest = new Request("POST", "/_bulk");
StringBuilder bulkJsonBuilder = new StringBuilder();
for (int i = 0; i < 5000; i++) {
// 請(qǐng)將field和value替換為實(shí)際業(yè)務(wù)字段與值
bulkJsonBuilder.append("{\"index\":{\"_index\":\"").append(indexName).append("\",\"_id\":\"").append(i).append("\"}}").append("\n");
String value = random.nextInt() + "";
bulkJsonBuilder.append("{\"field1\":\"").append(value).append("\",\"field2\":\"").append(value).append("\"}").append("\n");
}
bulkRequest.setJsonEntity(bulkJsonBuilder.toString());
response = restClient.performRequest(bulkRequest);
// 發(fā)送刷新請(qǐng)求，強(qiáng)制已寫數(shù)據(jù)可見(jiàn)
response = restClient.performRequest(new Request("POST", "/" + indexName + "/_refresh"));
responseBody = EntityUtils.toString(response.getEntity());
System.out.println("responseBody = " + responseBody);
// 查詢索引中所有數(shù)據(jù)，默認(rèn)最多返回10條查詢結(jié)果
response = restClient.performRequest(new Request("GET", "/" + indexName + "/_search"));
responseBody = EntityUtils.toString(response.getEntity());
System.out.println("responseBody = " + responseBody);
// 查詢索引中文檔id為"0"的數(shù)據(jù)
response = restClient.performRequest(new Request("GET", "/" + indexName + "/_doc/0"));
responseBody = EntityUtils.toString(response.getEntity());
System.out.println("responseBody = " + responseBody);
// 刪除索引
response = restClient.performRequest(new Request("DELETE", "/" + indexName));
responseBody = EntityUtils.toString(response.getEntity());
System.out.println("responseBody = " + responseBody);
} catch (Exception e) {
System.out.println("msg: " + e.getMessage());
}
}
}執(zhí)行成功后將返回如下結(jié)果：
responseBody = {"acknowledged":true,"shards_acknowledged":true,"index":"lindorm_index"}
responseBody = {"_shards":{"total":1,"successful":1,"failed":0}}
responseBody = {"took":6,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":{"value":5000,"relation":"eq"},"max_score":1.0,"hits":[{"_index":"lindorm_index","_id":"0","_score":1.0,"_source":{"field1":"2127821774","field2":"2127821774"}},{"_index":"lindorm_index","_id":"1","_score":1.0,"_source":{"field1":"1820331840","field2":"1820331840"}},{"_index":"lindorm_index","_id":"2","_score":1.0,"_source":{"field1":"-388903172","field2":"-388903172"}},{"_index":"lindorm_index","_id":"3","_score":1.0,"_source":{"field1":"-68048869","field2":"-68048869"}},{"_index":"lindorm_index","_id":"4","_score":1.0,"_source":{"field1":"1865955199","field2":"1865955199"}},{"_index":"lindorm_index","_id":"5","_score":1.0,"_source":{"field1":"1088273523","field2":"1088273523"}},{"_index":"lindorm_index","_id":"6","_score":1.0,"_source":{"field1":"-1529281106","field2":"-1529281106"}},{"_index":"lindorm_index","_id":"7","_score":1.0,"_source":{"field1":"-1185412160","field2":"-1185412160"}},{"_index":"lindorm_index","_id":"8","_score":1.0,"_source":{"field1":"-1243760053","field2":"-1243760053"}},{"_index":"lindorm_index","_id":"9","_score":1.0,"_source":{"field1":"1066058716","field2":"1066058716"}}]}}
responseBody = {"_index":"lindorm_index","_id":"0","_version":1,"_seq_no":0,"_primary_term":1,"found":true,"_source":{"field1":"2127821774","field2":"2127821774"}}
responseBody = {"acknowledged":true}文檔內(nèi)容是否對(duì)您有幫助？