JavaDB 整合 ElasticSearch

Java 提供了一个 Elastic 类，用于简化与 ElasticSearch 的整合过程以及执行相关的 ES 操作。本文档将介绍如何在 Java 项目中通过配置类来实现与 ElasticSearch 的整合。

使用 JavaDB 整合 ElasticSearch

添加依赖

    <dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>elasticsearch-rest-high-level-client</artifactId>
      <version>7.10.0</version>
    </dependency>
    <dependency>
      <groupId>com.litongjava</groupId>
      <artifactId>java-db</artifactId>
      <version>{java-db.version}</version>
    </dependency>

配置文件 (app.properties)

首先，在项目的配置文件中定义 ElasticSearch 的连接信息：

ELASTICSEARCH_DSN=http://elastic:YourElasticPassword@192.168.1.2:9200

配置类 (ElasticSearchConfig.java)

接下来，编写配置类来初始化 ElasticSearch 客户端并将其与应用程序集成：

import java.io.IOException;

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.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;

import com.litongjava.es.client.Elastic;
import com.litongjava.es.client.EsDSNUtils;
import com.litongjava.es.client.EsDSN;
import com.litongjava.jfinal.aop.annotation.AConfiguration;
import com.litongjava.jfinal.aop.annotation.AInitialization;
import com.litongjava.tio.boot.server.TioBootServer;
import com.litongjava.tio.utils.environment.EnvUtils;
import com.litongjava.tio.utils.hutool.StrUtil;

import lombok.extern.slf4j.Slf4j;

@AConfiguration
@Slf4j
public class ElasticSearchConfig {

  @Initialization
  public void config() {
    // 从环境变量或配置文件中读取 DSN
    String dsn = EnvUtils.getStr("ELASTICSEARCH_DSN");

    if (StrUtil.isEmpty(dsn)) {
      log.error("ElasticSearch DSN 未设置");
      return;
    }

    // 解析 DSN
    EsDSN esDSN = EsDSNUtils.parse(dsn);

    // 创建 HttpHost 实例
    HttpHost httpHost = new HttpHost(esDSN.getHost(), esDSN.getPort(), esDSN.getSchema());

    // 配置 RestClientBuilder
    RestClientBuilder builder = RestClient.builder(httpHost);

    String username = esDSN.getUsername();
    String password = esDSN.getPassword();

    if (StrUtil.isNotEmpty(username)) {
      // 设置凭证提供者
      CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
      credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));

      builder.setHttpClientConfigCallback(httpClientBuilder ->
          httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
    }

    // 创建 RestHighLevelClient
    RestHighLevelClient client = new RestHighLevelClient(builder);

    // 将客户端添加到 Elastic 管理类
    Elastic.setClient(client);

    // 确保在关闭应用时关闭客户端
    TioBootServer.me().addDestroyMethod(() -> {
      try {
        client.close();
      } catch (IOException e) {
        log.error("关闭 ElasticSearch 客户端时出错", e);
      }
    });

    // 测试连接状态
    try {
      boolean isConnected = client.ping(RequestOptions.DEFAULT);
      log.info("ElasticSearch 连接状态: {}", isConnected);
    } catch (IOException e) {
      log.error("无法连接到 ElasticSearch", e);
    }
  }
}

说明

• 配置文件：通过 app.properties 文件中的 ELASTICSEARCH_DSN 来指定 ElasticSearch 的连接信息，包括协议、用户名、密码和主机地址。
• 配置类：ElasticSearchConfig 类负责读取配置文件中的 DSN，解析连接信息，并初始化 RestHighLevelClient。该客户端将被设置到 Elastic 类中进行管理。
• 资源管理：在应用关闭时，通过 TioBootServer 的 addDestroyMethod 方法确保客户端被正确关闭。
• 连接测试：配置类在初始化过程中会测试 ElasticSearch 的连接状态，并将结果记录到日志中。

通过以上步骤，Java 应用程序就可以方便地与 ElasticSearch 整合，实现对 ElasticSearch 的各种操作。

SpringBoot 使用 Java-Db 整合 ES

添加依赖

    <dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>elasticsearch-rest-high-level-client</artifactId>
      <version>7.10.0</version>
    </dependency>
    <dependency>
      <groupId>com.litongjava</groupId>
      <artifactId>java-db</artifactId>
      <version>{java-db.version}</version>
    </dependency>

添加配置类

使用 Spring-boot 的 PostConstruct 注解

import java.io.IOException;

import javax.annotation.PostConstruct;

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.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.context.annotation.Configuration;

import com.litongjava.es.client.Elastic;
import com.litongjava.es.client.EsDSN;
import com.litongjava.es.client.EsDSNUtils;
import com.litongjava.jfinal.aop.annotation.AConfiguration;
import com.litongjava.jfinal.aop.annotation.AInitialization;
import com.litongjava.tio.utils.environment.EnvUtils;
import com.litongjava.tio.utils.hutool.StrUtil;

import lombok.extern.slf4j.Slf4j;

@AConfiguration
@Slf4j
@Configuration
public class ElasticSearchConfig {

  @Initialization
  @PostConstruct
  public void config() {
    // 从环境变量或配置文件中读取DSN
    String dsn = EnvUtils.getStr("ELASTICSEARCH_DSN");

    if (dsn == null || dsn.isEmpty()) {
      System.out.println("DSN is not set");
      return;
    }

    // 解析DSN
    EsDSN esInfo = EsDSNUtils.parse(dsn);

    // 创建 HttpHost 实例
    HttpHost httpHost = new HttpHost(esInfo.getHost(), esInfo.getPort(), esInfo.getSchema());

    // 配置 RestClientBuilder
    RestClientBuilder builder = RestClient.builder(httpHost);

    String username = esInfo.getUsername();
    String password = esInfo.getPassword();
    if (StrUtil.isNotEmpty(username)) {
      // 设置凭证提供者
      CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
      credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));

      builder.setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
    }

    // 创建 RestHighLevelClient
    RestHighLevelClient client = new RestHighLevelClient(builder);

    // 添加到EsClient
    Elastic.setClient(client);

    // 测试连接状态
    try {
      log.info("ping es server:{}", client.ping(RequestOptions.DEFAULT));
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}