通过Java语言连接GeminiDB Influx实例

本章节介绍了通过Java语言连接GeminiDB Influx实例的方法。

pom文件依赖

<dependency>
  <groupId>org.influxdb</groupId>
  <artifactId>influxdb-java</artifactId>
  <version>2.21</version>
</dependency>

package influxdb;

 import java.security.SecureRandom;
 import java.security.cert.X509Certificate;
 import java.util.concurrent.TimeUnit;
 import javax.net.ssl.SSLContext;

 import okhttp3.OkHttpClient;
 import org.influxdb.InfluxDB;
 import org.influxdb.InfluxDBFactory;
 import org.influxdb.dto.Point;
 import org.influxdb.dto.Query;
 import org.influxdb.dto.QueryResult;

 import org.apache.http.ssl.SSLContexts;
 import javax.net.ssl.*;

 public class demo {
     public static void main(String[] args) {
         OkHttpClient.Builder client = new OkHttpClient.Builder()
             .connectTimeout(10, TimeUnit.SECONDS)
             .writeTimeout(10, TimeUnit.SECONDS)
             .readTimeout(10, TimeUnit.SECONDS)
             .retryOnConnectionFailure(true);

         client.sslSocketFactory(defaultSslSocketFactory(), defaultTrustManager());
         client.hostnameVerifier(noopHostnameVerifier());

         // 认证用的用户名和密码直接写到代码中有很大的安全风险，建议在配置文件或者环境变量中存放(密码应密文存放、使用时解密)，确保安全；
         // 本示例以用户名和密码保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量(环境变量名称请根据自身情况进行设置)EXAMPLE_USERNAME_ENV和EXAMPLE_PASSWORD_ENV。
         String username = System.getenv("EXAMPLE_USERNAME_ENV");
         String password = System.getenv("EXAMPLE_PASSWORD_ENV");
         final String serverURL = "https://127.0.0.1:8086", username = username, password = password;

         InfluxDB influxdb = InfluxDBFactory.connect(serverURL, username, password, client);

         // Create a database...
         String databaseName = "foo";
         influxdb.query(new Query("CREATE DATABASE " + databaseName, databaseName));
         influxdb.setDatabase(databaseName);

         // Write points to influxdb.
         influxdb.write(Point.measurement("bar")
             .time(System.currentTimeMillis(), TimeUnit.MILLISECONDS)
             .tag("location", "chengdu")
             .addField("temperature", 22)
             .build());

         // Query your data using InfluxQL.
         QueryResult queryResult = influxdb.query(new Query("SELECT * FROM bar", databaseName));

         // Close it if your application is terminating or you are not using it anymore.
         influxdb.close();
     }

     private static X509TrustManager defaultTrustManager() {
         return new X509TrustManager() {
             public X509Certificate[] getAcceptedIssuers() {
                 return new X509Certificate[0];
             }

             public void checkClientTrusted(X509Certificate[] certs, String authType) {
             }

             public void checkServerTrusted(X509Certificate[] certs, String authType) {
             }
         };
     }

     private static SSLSocketFactory defaultSslSocketFactory() {
         try {
             SSLContext sslContext = SSLContexts.createDefault();

             sslContext.init(null, new TrustManager[] {
                 defaultTrustManager()
             }, new SecureRandom());
             return sslContext.getSocketFactory();
         } catch (Exception e) {
             throw new RuntimeException(e);
         }

     }

     private static HostnameVerifier noopHostnameVerifier() {
         return new HostnameVerifier() {
             @Override
             public boolean verify(final String s, final SSLSession sslSession) { 
                 return true;//true 表示使用ssl方式，但是不校验ssl证书，建议使用这种方式
             }
         };
     }
 }

package influxdb;

import okhttp3.OkHttpClient;
import org.influxdb.InfluxDB;
import org.influxdb.InfluxDBFactory;
import org.influxdb.dto.Point;
import org.influxdb.dto.Query;
import org.influxdb.dto.QueryResult;

import java.util.concurrent.TimeUnit;

public class demoNoSSL {
    public static void main(String[] args) {
        OkHttpClient.Builder client = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10, TimeUnit.SECONDS)
                .readTimeout(10, TimeUnit.SECONDS)
                .retryOnConnectionFailure(true);

        // 认证用的用户名和密码直接写到代码中有很大的安全风险，建议在配置文件或者环境变量中存放(密码应密文存放、使用时解密)，确保安全；
        // 本示例以用户名和密码保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量(环境变量名称请根据自身情况进行设置)EXAMPLE_USERNAME_ENV和EXAMPLE_PASSWORD_ENV。
        String username = System.getenv("EXAMPLE_USERNAME_ENV");
        String password = System.getenv("EXAMPLE_PASSWORD_ENV");
        final String serverURL = "http://127.0.0.1:8086", username = username, password = password;
        InfluxDB influxdb = InfluxDBFactory.connect(serverURL, username, password, client);

        // Create a database...
        String databaseName = "foo";

        influxdb.query(new Query("CREATE DATABASE " + databaseName, databaseName));
        influxdb.setDatabase(databaseName);

        // Write points to influxdb.
        influxdb.write(Point.measurement("bar")
                .time(System.currentTimeMillis(), TimeUnit.MILLISECONDS)
                .tag("location", "chengdu")
                .addField("temperature", 22)
                .build());

        // Query your data using InfluxQL.
        QueryResult queryResult = influxdb.query(new Query("SELECT * FROM bar", databaseName));

        // Close it if your application is terminating or you are not using it anymore.
        influxdb.close();
    }
}

package influxdb;

import okhttp3.ConnectionPool;
import okhttp3.OkHttpClient;
import org.influxdb.InfluxDB;
import org.influxdb.InfluxDBFactory;
import org.influxdb.dto.Point;
import org.influxdb.dto.Query;
import org.influxdb.dto.QueryResult;

import java.util.concurrent.TimeUnit;

public class demoConnectionPool {
    public static void main(String[] args) {
        // 客户端连接池功能基于OkHttpClient实现
        OkHttpClient.Builder client = new OkHttpClient().newBuilder();
        client.connectTimeout(10, TimeUnit.SECONDS);
        client.readTimeout(10, TimeUnit.SECONDS);
        client.writeTimeout(10, TimeUnit.SECONDS);
        // 建议设为true，屏蔽部分连接错误，并自动进行重试
        client.retryOnConnectionFailure(true);
        // maxIdleConnections指连接池最多维护的未使用的Idle连接数量，默认值是5
        // 超过阈值的idle连接会由连接池关闭，关闭后sockets进入TIME_WAIT状态等待系统回收，该参数需根据实际连接数适当调整
        client.connectionPool(new ConnectionPool(5, 30, TimeUnit.SECONDS));

        // 认证用的用户名和密码直接写到代码中有很大的安全风险，建议在配置文件或者环境变量中存放(密码应密文存放、使用时解密)，确保安全；
        // 本示例以用户名和密码保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量(环境变量名称请根据自身情况进行设置)EXAMPLE_USERNAME_ENV和EXAMPLE_PASSWORD_ENV。
        String username = System.getenv("EXAMPLE_USERNAME_ENV");
        String password = System.getenv("EXAMPLE_PASSWORD_ENV");
        final String serverURL = "http://127.0.0.1:8086", username = username, password = password;
        InfluxDB influxdb = InfluxDBFactory.connect(serverURL, username, password, client);

        // Create a database...
        String databaseName = "foo";

        influxdb.query(new Query("CREATE DATABASE " + databaseName, databaseName));
        influxdb.setDatabase(databaseName);

        // Write points to influxdb.
        influxdb.write(Point.measurement("bar")
                .time(System.currentTimeMillis(), TimeUnit.MILLISECONDS)
                .tag("location", "chengdu")
                .addField("temperature", 22)
                .build());

        // Query your data using InfluxQL.
        QueryResult queryResult = influxdb.query(new Query("SELECT * FROM bar", databaseName));

        // Close it if your application is terminating or you are not using it anymore.
        influxdb.close();
    }
}

/**
         使用场景：
         * 当采用ELB连接的时候，客户端一次性发送很多次查询请求。
         * 如果采用http长连接，会导致大部分查询请求打到一个InfluxDB节点上，导致负载不均衡。
         此时采用http短连接（设置请求头中:Connection=close）可以解决这一问题，实现InfluxDB各节点负载均衡。
         */
/**
         此方式只展示部分代码
         */
OkHttpClient.Builder client = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10, TimeUnit.SECONDS)
                .readTimeout(10, TimeUnit.SECONDS)
                .retryOnConnectionFailure(true)
                .addNetworkInterceptor(chain -> {
                    Request newRequest = chain.request().newBuilder().header("Connection", "close").build();
                    return chain.proceed(newRequest);
                });

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