java使用influxDB数据库的详细代码

下面我将为您详细讲解Java使用InfluxDB数据库的详细代码。

1. InfluxDB简介

InfluxDB是一种开源的分布式时序数据库，广泛应用于监控、IoT、实时分析等领域。它具有以下特点：

• 高效的写入和查询
• 支持SQL查询语言
• 支持数据压缩和自动删除
• 支持分布式架构

2. 安装InfluxDB

在使用InfluxDB前，需要先下载并安装InfluxDB。官网提供了多种安装方式，这里以Docker方式为例。

# 先安装Docker
sudo apt install docker.io

# 拉取InfluxDB镜像
sudo docker pull influxdb

# 启动InfluxDB容器
sudo docker run -p 8086:8086 -v influxdb:/var/lib/influxdb influxdb

3. 连接InfluxDB

Java中连接InfluxDB的方式有多种，这里介绍使用Java API方式连接。需要先在Maven中添加InfluxDB Java API的依赖：

<dependency>
    <groupId>org.influxdb</groupId>
    <artifactId>influxdb-java</artifactId>
    <version>2.16</version>
</dependency>

在连接InfluxDB前，需要定义InfluxDB连接的配置文件：

InfluxDBConfig influxDBConfig = InfluxDBConfig.builder()
    .url("http://localhost:8086")
    .username("admin")
    .password("admin")
    .database("test")
    .build();

根据配置文件创建InfluxDB实例：

InfluxDB influxDB = InfluxDBFactory.connect(influxDBConfig);

4. 插入数据

插入数据需要先定义数据模型。以一个传感器温度数据为例：

@Data
public class SensorData {
    private String sensorId;
    private Timestamp timestamp;
    private Double temperature;
}

使用Java API方式插入数据：

SensorData sensorData = new SensorData();
sensorData.setSensorId("s1");
sensorData.setTimestamp(new Timestamp(System.currentTimeMillis()));
sensorData.setTemperature(22.5);

Point point = Point.measurement("temperature")
    .time(sensorData.getTimestamp().getTime(), TimeUnit.MILLISECONDS)
    .tag("sensorId", sensorData.getSensorId())
    .addField("temperature", sensorData.getTemperature())
    .build();

influxDB.write(point);

5. 查询数据

查询数据需要先定义查询语句。以查询传感器s1最近20条温度数据为例：

String query = String.format("SELECT temperature FROM temperature WHERE sensorId='s1' ORDER BY time DESC LIMIT 20");

使用Java API方式查询数据：

QueryResult queryResult = influxDB.query(new Query(query, database));
List<QueryResult.Result> results = queryResult.getResults();

if (results != null && !results.isEmpty()) {
    QueryResult.Result result = results.get(0);

    if (result.getSeries() != null && !result.getSeries().isEmpty()) {
        QueryResult.Series series = result.getSeries().get(0);

        List<String> columns = series.getColumns();
        List<List<Object>> values = series.getValues();

        // 处理查询结果
        for (List<Object> value : values) {
            Double temperature = Double.parseDouble(value.get(columns.indexOf("temperature")).toString());
            System.out.println(temperature);
        }
    }
}

6. 完整代码示例

以下是完整的Java使用InfluxDB的代码示例。

import lombok.Data;
import org.influxdb.InfluxDB;
import org.influxdb.InfluxDBFactory;
import org.influxdb.InfluxDBIOException;
import org.influxdb.InfluxDBIOException.InfluxDBIOExceptionBuilder;
import org.influxdb.InfluxDBResponseException;
import org.influxdb.dto.Point;
import org.influxdb.dtO.Point.Builder;
import org.influxdb.dto.QueryResult;

import java.sql.Timestamp;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class InfluxDBExample {
    public static void main(String[] args) {
        // 数据库连接配置
        InfluxDBConfig influxDBConfig = InfluxDBConfig.builder()
            .url("http://localhost:8086")
            .username("admin")
            .password("admin")
            .database("test")
            .build();

        // 创建InfluxDB实例
        InfluxDB influxDB = InfluxDBFactory.connect(influxDBConfig);

        // 插入数据
        SensorData sensorData = new SensorData();
        sensorData.setSensorId("s1");
        sensorData.setTimestamp(new Timestamp(System.currentTimeMillis()));
        sensorData.setTemperature(22.5);

        Point point = Point.measurement("temperature")
            .time(sensorData.getTimestamp().getTime(), TimeUnit.MILLISECONDS)
            .tag("sensorId", sensorData.getSensorId())
            .addField("temperature", sensorData.getTemperature())
            .build();

        influxDB.write(point);

        // 查询数据
        String query = String.format("SELECT temperature FROM temperature WHERE sensorId='s1' ORDER BY time DESC LIMIT 20");

        QueryResult queryResult = influxDB.query(new Query(query, database));
        List<QueryResult.Result> results = queryResult.getResults();

        if (results != null && !results.isEmpty()) {
            QueryResult.Result result = results.get(0);

            if (result.getSeries() != null && !result.getSeries().isEmpty()) {
                QueryResult.Series series = result.getSeries().get(0);

                List<String> columns = series.getColumns();
                List<List<Object>> values = series.getValues();

                // 处理查询结果
                for (List<Object> value : values) {
                    Double temperature = Double.parseDouble(value.get(columns.indexOf("temperature")).toString());
                    System.out.println(temperature);
                }
            }
        }

        // 关闭InfluxDB连接
        influxDB.close();
    }

    @Data
    public static class SensorData {
        private String sensorId;
        private Timestamp timestamp;
        private Double temperature;
    }

    @Data
    public static class InfluxDBConfig {
        private String url;
        private String username;
        private String password;
        private String database;

        public static Builder builder() {
            return new Builder();
        }

        public static class Builder {
            private InfluxDBConfig config = new InfluxDBConfig();

            public Builder url(String url) {
                config.setUrl(url);
                return this;
            }

            public Builder username(String username) {
                config.setUsername(username);
                return this;
            }

            public Builder password(String password) {
                config.setPassword(password);
                return this;
            }

            public Builder database(String database) {
                config.setDatabase(database);
                return this;
            }

            public InfluxDBConfig build() {
                return config;
            }
        }
    }
}

以上是Java使用InfluxDB的完整攻略，希望能对您有所帮助。