ElasticSearch8教程笔记

基于JDK17,可以兼容JDK8,但是建议用JDK17性能更好。
完全支持ARM架构。

kibana操作

put 、post操作在有指定主键id时可以是修改也可以是添加。

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搜索结果评分机制

TF-IDF公式
- boost * idf * tf
- boost 权重默认2.2
- 可以手动设置查询权重值
TF:词频
IDF: 逆文档频率

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Java API操作

推荐使用Lamda表达式构建增删改查API方法。

pom依赖

<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<elastic.version>8.1.0</elastic.version>
</properties>
<dependencies>
<dependency>
<groupId>org.elasticsearch.plugin</groupId>
<artifactId>x-pack-sql-jdbc</artifactId>
<version>8.1.0</version>
</dependency>
<dependency>
<groupId>co.elastic.clients</groupId>
<artifactId>elasticsearch-java</artifactId>
<version>${elastic.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.12.3</version>
</dependency>
<dependency>
<groupId>jakarta.json</groupId>
<artifactId>jakarta.json-api</artifactId>
<version>2.0.1</version>
</dependency>
</dependencies>

获取连接

 导入的类
import co.elastic.clients.elasticsearch.*;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.apache.http.auth.*;
import org.apache.http.client.*;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.impl.client.*;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.apache.http.ssl.*;
import org.elasticsearch.client.*;
import javax.net.ssl.SSLContext;
import java.io.InputStream;
import java.nio.file.*;
import java.security.KeyStore;
import java.security.cert.*;
# 获取客户端对象
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY,
new UsernamePasswordCredentials("elastic", "O3x0hfu7i=ZbQvlktCnd"));
Path caCertificatePath = Paths.get("ca.crt");
CertificateFactory factory =
CertificateFactory.getInstance("X.509");
Certificate trustedCa;
try (InputStream is = Files.newInputStream(caCertificatePath)) {
trustedCa = factory.generateCertificate(is);
}
KeyStore trustStore = KeyStore.getInstance("pkcs12");
trustStore.load(null, null);
trustStore.setCertificateEntry("ca", trustedCa);
SSLContextBuilder sslContextBuilder = SSLContexts.custom()
.loadTrustMaterial(trustStore, null);
final SSLContext sslContext = sslContextBuilder.build();
RestClientBuilder builder = RestClient.builder(
new HttpHost("linux1", 9200, "https"))
.setHttpClientConfigCallback(new
RestClientBuilder.HttpClientConfigCallback() {
@Override
public HttpAsyncClientBuilder customizeHttpClient(
HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setSSLContext(sslContext)
.setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
.setDefaultCredentialsProvider(credentialsProvider);
}
});
RestClient restClient = builder.build();
ElasticsearchTransport transport = new RestClientTransport(
restClient, new JacksonJsonpMapper());
ElasticsearchClient client = new ElasticsearchClient(transport);
ElasticsearchAsyncClient asyncClient = new ElasticsearchAsyncClient(transport);
transport.close();