一、前言

上面幾篇文章中，介紹了Influx在Linux和Windows上的使用之后膜楷，本節(jié)開(kāi)始介紹Influx在Java中的使用旭咽，先提供一個(gè)InfluxDB Java API 封裝的工具類，方便大家直接上手使用赌厅。

二穷绵、InfluxDB工具類

2.1 導(dǎo)入依賴包

使用maven工具導(dǎo)入如下依賴的jar包：

<dependency>
        <groupId>org.influxdb</groupId>
        <artifactId>influxdb-java</artifactId>
        <version>2.10</version>
</dependency>

2.2 編寫(xiě)工具類代碼

package com.common.utils.influxdb;

import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.influxdb.InfluxDB;
import org.influxdb.InfluxDB.ConsistencyLevel;
import org.influxdb.InfluxDBFactory;
import org.influxdb.dto.BatchPoints;
import org.influxdb.dto.Point;
import org.influxdb.dto.Point.Builder;
import org.influxdb.dto.Pong;
import org.influxdb.dto.Query;
import org.influxdb.dto.QueryResult;

@Service("tsdbService")
public class TsdbServiceImpl implements TsdbService{

    private static final Logger logger = LoggerFactory.getLogger(TsdbServiceImpl.class);

    private static final InfluxDB.ConsistencyLevel CONSISTENCY_LEVEL = InfluxDB.ConsistencyLevel.ANY;

    private static final TimeUnit PRECESION = TimeUnit.SECONDS;

    @Value("${tsdb.server.hosts}")
    private String hosts;

    @Value("${tsdb.server.port}")
    private String port;

    /**
     * 用戶名
     */
    @Value("${tsdb.server.username}")
    private String username;
    /**
     * 密碼
     */
    @Value("${tsdb.server.password}")
    private String password;
    /**
     * 數(shù)據(jù)庫(kù)
     */
    @Value("${tsdb.server.database}")
    private String database;
    /**
     * 保留策略
     */
    @Value("${tsdb.server.retentionpolicy}")
    private String retentionPolicy;

    private InfluxDB influxDB;

    @PostConstruct
    public void init() {
            List<String> serverAddressList = new ArrayList<>();
        for (String host : hosts.split(",")) {
            serverAddressList.add(String.format("%s:%s", host, port));
                }
            influxDB = InfluxDBFactory.connect(serverAddressList, username, password);  

        try {
            // 如果指定的數(shù)據(jù)庫(kù)不存在，則新建一個(gè)新的數(shù)據(jù)庫(kù)特愿，并新建一個(gè)默認(rèn)的數(shù)據(jù)保留規(guī)則
            if (!this.databaseExist(database)) {
                createDatabase(database);
                createRetentionPolicy();
            }
        } catch (Exception e) {
            // 該數(shù)據(jù)庫(kù)可能設(shè)置動(dòng)態(tài)代理仲墨，不支持創(chuàng)建數(shù)據(jù)庫(kù)
            logger.error("[TsdbService] occur error when init tsdb, err msg: {}", e);
        } finally {
            influxDB.setRetentionPolicy(retentionPolicy);
        }

        influxDB.setLogLevel(InfluxDB.LogLevel.NONE);

        // Flush every 1000 Points, at least every 100ms
        // bufferLimit represents the maximum number of points can stored in the retry buffer
        // exceptionHandler represents a consumer function to handle asynchronous errors
        // threadFactory represents the ThreadFactory instance to be used
        influxDB.enableBatch(BatchOptions.DEFAULTS
                .actions(1000)
                .flushDuration(100)
                .bufferLimit(10)
                .exceptionHandler((points, e) -> {
                    List<Point> target = new ArrayList<>();
                    points.forEach(target::add);
                    String msg = String.format("failed to write points:%s\n", target.toString().substring(0, 10000));
                    logger.error(msg, e);
                })
                .threadFactory(
                        Executors.defaultThreadFactory()
                ));
    }

    /**
     * 測(cè)試連接是否正常
     * 
     * @return true 正常
     */
    public boolean ping() {
        boolean isConnected = false;
        Pong pong;
        try {
            pong = influxDB.ping();
            if (pong != null) {
                isConnected = true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return isConnected;
    }

    @Override
    public void createDatabase(String database) {
        influxDB.query(new Query("CREATE DATABASE " + database, ""));
    }

    @Override
    public void dropDatabase(String database) {
        influxDB.query(new Query("DROP DATABASE " + database, ""));
    }

    @Override
    public boolean databaseExist(String database) {
        return influxDB.databaseExists(database);
    }

    @Override
    public void createRetentionPolicy() {
        String command = String.format("CREATE RETENTION POLICY \"%s\" ON \"%s\" DURATION %s REPLICATION %s DEFAULT",
                "default_policy", database, "90d", 3);
        this.query(command);
    }

    @Override
    public void createRetentionPolicy(String database, String policyName, String duration, int replication, Boolean isDefault) {
        String sql = String.format("CREATE RETENTION POLICY \"%s\" ON \"%s\" DURATION %s REPLICATION %s ", policyName,
                database, duration, replication);
        if (isDefault) {
            sql = sql.concat(" DEFAULT");
        }
        this.query(sql);
    }

    @Override
    public void dropRetentionPolicy() {
        this.dropRetentionPolicy(database, retentionPolicy);
    }

    @Override
    public void dropRetentionPolicy(String database, String retentionPolicy) {
        String sql = String.format("DROP RETENTION POLICY %s ON %s", retentionPolicy, database);
        this.query(sql);
    }

    @Override
    public void createContinuousQuery(String measurement) {
        String cqName = String.format("cq_%s", measurement);
        String originMeasurement = String.format("%s.%s.%s", database, retentionPolicy, measurement);
        String cqMeasurement = String.format("%s.%s.%s_hour", database, extendPolicy, measurement);
        String sql = String.format("CREATE CONTINUOUS QUERY \"%s\" ON %s RESAMPLE EVERY 1h FOR 2h BEGIN SELECT MEAN(*) INTO %s FROM %s GROUP BY time(1h),* FILL(none) END",
                cqName, database, cqMeasurement, originMeasurement);

        this.query(sql);
    }

    @Override
    public boolean continuousQueryExists(String measurement) {
        String cqName = String.format("cq_%s", measurement);
        return continuousQueryExists(database, cqName);
    }

    @Override
    public boolean continuousQueryExists(String database, String cqName) {
        String sql = "SHOW CONTINUOUS QUERIES";
        QueryResult result = query(sql);
        List<QueryResult.Series> seriesList = result.getResults().get(0).getSeries();
        if (seriesList != null) {
            for (QueryResult.Series series : seriesList) {
                if (database.equals(series.getName())) {
                    List<List<Object>> continuousQueryList = series.getValues();
                    if (continuousQueryList == null) {
                        return false;
                    } else {
                        for (List<Object> queryResult : continuousQueryList) {
                            if (cqName.equals(queryResult.get(0))) {
                                return true;
                            }
                        }
                    }

                }
            }
        }
        return false;
    }

    @Override
    public void dropContinuousQuery(String databaseName, String cqName) {
        String sql = String.format("DROP CONTINUOUS QUERY %s ON %s", cqName, databaseName);
        QueryResult result = query(sql);
    }

    @Override
    public boolean measurementsExists(String measurement) {
        return measurementsExists(database, measurement);
    }

    @Override
    public boolean measurementsExists(String database, String measurement) {
        String sql = String.format("SHOW MEASUREMENTS ON %s", database);
        QueryResult result = query(sql);
        if (result != null) {
            List<QueryResult.Series> seriesList = result.getResults().get(0).getSeries();
            if (seriesList != null) {
                QueryResult.Series series = seriesList.get(0);
                List<List<Object>> valueList = series.getValues();
                for (List<Object> value : valueList) {
                    if (measurement.equals(value.get(0))) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

@Override
    public QueryResult query(String command) {
        return influxDB.query(new Query(command, database));
    }

    @Override
    public QueryResult dataQuery(String command) {
        return influxDB.query(new Query(command, database), TimeUnit.MILLISECONDS);
    }

    @Override
    public void insert(Point point1) {
        influxDB.write(point1);
    }

    @Override
    public void insert(String measurement, TimeUnit timeUnit, UniteMetricData data) {
        timeUnit = timeUnit == null ? TimeUnit.MILLISECONDS : timeUnit;
        Point point = pointBuilder(measurement, data.getTags(), data.getFields(), data.getTimestamp(), timeUnit);
        influxDB.write(database, retentionPolicy, point);
    }

    @Override
    public void batchInsert(BatchPoints batchPoints) {
        influxDB.write(batchPoints);
    }

    @Override
    public Point pointBuilder(String measurement,
                              Map<String, String> tags,
                              Map<String, Object> fields,
                              long time,
                              TimeUnit timeunit) {
        Point point = Point.measurement(measurement).time(time, timeunit).tag(tags).fields(fields).build();
        return point;
    }

    @Override
    public BatchPoints buildBatchPoints() {
        return this.batchPointsBuilder(database, CONSISTENCY_LEVEL, PRECESION);
    }

    @Override
    public BatchPoints batchPointsBuilder(String database, InfluxDB.ConsistencyLevel level, TimeUnit precision) {
        return batchPointsBuilder(database, level, precision, null);
    }

    @Override
    public BatchPoints batchPointsBuilder(String database, InfluxDB.ConsistencyLevel level, TimeUnit precision, String retentionPolicy) {
        return BatchPoints.database(database).consistency(level).precision(precision).retentionPolicy(retentionPolicy).build();
    }

三、使用示例

3.0 連通性測(cè)試

    /**
     * TSDB訪問(wèn)連通性檢查揍障，置于其他所有測(cè)試之前
     */
    @Before
    public void connectionTest() {
        boolean connected = tsdbService.ping();
        assertTrue(connected);
    }

3.1 查詢數(shù)據(jù)

InfluxDB支持一次查詢多個(gè)SQL目养，SQL之間用逗號(hào)隔開(kāi)即可。下面只演示下毒嫡，只有一條SQL的情況下癌蚁，怎么解析查詢返回的結(jié)果集。

       @Resource
    private TsdbService tsdbService;

    // 自測(cè)環(huán)境TSDB地址
    private static final String MASTER_URL = "10.185.3.150:8091";

    private static final String USERNAME = "root";

    private static final String PASSWORD = "root";

    private static final String DATABASE_NAME = "ncm_test_temp";

    private static final String RP_NAME = "default_policy";

    //測(cè)試數(shù)據(jù)表名兜畸，通常以namespace來(lái)命名
    private static final String MEASUREMENT_NAME = "NVS";

    private static final Integer QUERY_LIMIT = 10;

/**
     *  批量查詢操作單元測(cè)試
     */
    @Test
    public void batchQueryTest() {
        long beginTime = 1559613845000L;
        long endTime = 1559621045000L;

        Map<String, String> dimensionMap = new HashMap<>();
        dimensionMap.put("tag1", "tag1");

        // 帶時(shí)間范圍的查詢
        String condition = TSDBUtil.getQueryCondition(dimensionMap,beginTime,endTime);

        Object[] args = new Object[]{MEASUREMENT_NAME, condition, QUERY_LIMIT};
        String command = String.format("SELECT * FROM %s WHERE %s ORDER BY time ASC LIMIT %d", args);

        // 執(zhí)行查詢
        QueryResult results = tsdbService.dataQuery(command);
        if (results.getResults() == null) {
            System.out.println("Data is empty");
            return;
        }
        //results.getResults()是同時(shí)查詢多條SQL語(yǔ)句的返回值
        for (QueryResult.Result result : results.getResults()) {
            List<QueryResult.Series> series = result.getSeries();
            for (QueryResult.Series serie : series) {
                List<List<Object>> values = serie.getValues();//字段字集合
                List<String> colums = serie.getColumns();//字段名

                // 打印查詢結(jié)果
                System.out.println("colums:" + colums);
                for (List<Object> value : values) {
                    System.out.println("value:" + value);
                }

                // 封裝查詢結(jié)果
                List<Map<String, Object>> dataList = new LinkedList<>();
                for (int i=0;i<values.size();++i){
                    Map<String, Object> dataMap=new HashMap<>(colums.size());
                    for (int j=0;j<colums.size();++j){
                        dataMap.put(colums.get(j),values.get(i).get(j));
                    }
                    dataList.add(dataMap);
                }

                // dataList即可作為返回給用戶的查詢數(shù)據(jù)的基礎(chǔ)格式
                System.out.println(dataList);

            }
        }

        /**
         * 標(biāo)準(zhǔn)化之前：
         *
         * colums:[time, field1, field2, tag1, tag2]
         * value:[1.550599292E12, efs, 444444.0, tag1, tag2]
         * value:[1.550595692E12, bcd, 333333.0, tag1, tag2]
         * value:[1.550592092E12, abc, 123456.0, tag1, tag2]
         *
         * 標(biāo)準(zhǔn)化之后：
         * [
         *     {
         *         tag1=tag1,
         *         field1=efs,
         *         time=1.550599292E12,
         *         field2=444444.0,
         *         tag2=tag2
         *     },
         *     {
         *         tag1=tag1,
         *         field1=bcd,
         *         time=1.550595692E12,
         *         field2=333333.0,
         *         tag2=tag2
         *     },
         *     {
         *         tag1=tag1,
         *         field1=abc,
         *         time=1.550592092E12,
         *         field2=123456.0,
         *         tag2=tag2
         *     }
         * ]
         */
    }

取數(shù)據(jù)的時(shí)候努释，注意空值判斷，本例將返回?cái)?shù)據(jù)先進(jìn)行判空oneResult.getSeries() != null咬摇，然后調(diào)用oneResult.getSeries().getValues().get(0)獲取到第一條SQL的返回結(jié)果集伐蒂，然后遍歷valueList，取出每條記錄中的目標(biāo)字段值菲嘴。

InfluxDB封裝的結(jié)果集有點(diǎn)深饿自，主要是由于支持多條SQL一次性查詢，可以提高查詢速度龄坪，這個(gè)地方有別于關(guān)系型數(shù)據(jù)庫(kù)的使用昭雌。

3.2 插入單條數(shù)據(jù)

InfluxDB的字段類型，由第一條插入的值得類型決定健田；tags的類型只能是String型烛卧，可以作為索引，提高檢索速度妓局。

public static void main(String[] args) {
        InfluxDBConnection influxDBConnection = new InfluxDBConnection("admin", "admin", "1.1.1.1", "db-test", "hour");
        Map<String, String> tags = new HashMap<String, String>();
        tags.put("tag1", "標(biāo)簽值");
        Map<String, Object> fields = new HashMap<String, Object>();
        fields.put("field1", "String類型");
        // 數(shù)值型总放，InfluxDB的字段類型，由第一天插入的值得類型決定
        fields.put("field2", 3.141592657);
        // 時(shí)間使用毫秒為單位
        influxDBConnection.insert("表名", tags, fields, System.currentTimeMillis(), TimeUnit.MILLISECONDS);
    }

另外一個(gè)測(cè)試用例：

public class UniteMetricData implements Serializable {

    private static final long serialVersionUID = 8968059029015805484L;

    private Map<String, String> tags;

    private Map<String, Object> fields;

    private long timestamp;

    public UniteMetricData(Map<String, String> tags, Map<String, Object> fields, long timestamp) {
        this.tags = tags;
        this.fields = fields;
        this.timestamp = timestamp;
    }

    public Map<String, String> getTags() {
        return tags;
    }

    public void setTags(Map<String, String> tags) {
        this.tags = tags;
    }

    public Map<String, Object> getFields() {
        return fields;
    }

    public void setFields(Map<String, Object> fields) {
        this.fields = fields;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(long timestamp) {
        this.timestamp = timestamp;
    }
}

@Test
    public void writeTest() throws InterruptedException {
        Map<String, String> tags  = new HashMap<>();
        tags.put("host", "ncm-test-01");
        tags.put("projectId", "c57212bdec1345cd95107ef3109777");

        Map<String, Object> fields = new HashMap<>();
        fields.put("cpuUsage", 2.17);

        UniteMetricData data = new UniteMetricData(tags, fields, System.currentTimeMillis());

        tsdbService.insert(MEASUREMENT_NAME, TimeUnit.MILLISECONDS, data);

        Thread.sleep(1000);
        QueryResult queryResult = tsdbService.query(String.format("SELECT cpuUsage FROM %s", MEASUREMENT_NAME));

        for (QueryResult.Result result : queryResult.getResults()) {
            for (QueryResult.Series series : result.getSeries()) {
                System.out.println(series.toString());
            }
        }
    }

3.3 批量寫(xiě)入數(shù)據(jù)的幾種方式

注：使用這兩種種方式好爬，要就這兩條數(shù)據(jù)都寫(xiě)入到同一數(shù)據(jù)庫(kù)下且tag相同,若tag不相同局雄，需將它們放到不同的BatchPoint對(duì)象中，否則會(huì)出現(xiàn)數(shù)據(jù)寫(xiě)入錯(cuò)亂問(wèn)題存炮。

3.3.1 方式一：通過(guò)BatchPoints組裝數(shù)據(jù)后炬搭，循環(huán)插入數(shù)據(jù)庫(kù)

public static void main(String[] args) {
        InfluxDBConnection influxDBConnection = new InfluxDBConnection("admin", "admin", "1.1.1.1", "db-test", "hour");
        Map<String, String> tags = new HashMap<String, String>();
        tags.put("tag1", "標(biāo)簽值");
        Map<String, Object> fields1 = new HashMap<String, Object>();
        fields1.put("field1", "abc");
        // 數(shù)值型蜈漓，InfluxDB的字段類型，由第一天插入的值得類型決定
        fields1.put("field2", 123456);
        Map<String, Object> fields2 = new HashMap<String, Object>();
        fields2.put("field1", "String類型");
        fields2.put("field2", 3.141592657);
        // 一條記錄值
        Point point1 = influxDBConnection.pointBuilder("表名", System.currentTimeMillis(), tags, fields1);
        Point point2 = influxDBConnection.pointBuilder("表名", System.currentTimeMillis(), tags, fields2);
        // 將兩條記錄添加到batchPoints中
        BatchPoints batchPoints1 = BatchPoints.database("db-test").tag("tag1", "標(biāo)簽值1").retentionPolicy("hour")
                .consistency(ConsistencyLevel.ALL).build();
        BatchPoints batchPoints2 = BatchPoints.database("db-test").tag("tag2", "標(biāo)簽值2").retentionPolicy("hour")
                .consistency(ConsistencyLevel.ALL).build();
        batchPoints1.point(point1);
        batchPoints2.point(point2);
        // 將兩條數(shù)據(jù)批量插入到數(shù)據(jù)庫(kù)中
        influxDBConnection.batchInsert(batchPoints1);
        influxDBConnection.batchInsert(batchPoints2);
    }

3.3.2 方式二：通過(guò)BatchPoints組裝數(shù)據(jù)宫盔，序列化后融虽，一次性插入數(shù)據(jù)庫(kù)

public static void main(String[] args) {
        InfluxDBConnection influxDBConnection = new InfluxDBConnection("admin", "admin", "1.1.1.1", "db-test", "hour");
        Map<String, String> tags1 = new HashMap<String, String>();
        tags1.put("tag1", "標(biāo)簽值");
        Map<String, String> tags2 = new HashMap<String, String>();
        tags2.put("tag2", "標(biāo)簽值");
        Map<String, Object> fields1 = new HashMap<String, Object>();
        fields1.put("field1", "abc");
        // 數(shù)值型，InfluxDB的字段類型灼芭，由第一天插入的值得類型決定
        fields1.put("field2", 123456);
        Map<String, Object> fields2 = new HashMap<String, Object>();
        fields2.put("field1", "String類型");
        fields2.put("field2", 3.141592657);
        // 一條記錄值
        Point point1 = influxDBConnection.pointBuilder("表名", System.currentTimeMillis(), tags1, fields1);
        Point point2 = influxDBConnection.pointBuilder("表名", System.currentTimeMillis(), tags2, fields2);
        BatchPoints batchPoints1 = BatchPoints.database("db-test").tag("tag1", "標(biāo)簽值1")
                .retentionPolicy("hour").consistency(ConsistencyLevel.ALL).build();
        // 將兩條記錄添加到batchPoints中
        batchPoints1.point(point1);
        BatchPoints batchPoints2 = BatchPoints.database("db-test").tag("tag2", "標(biāo)簽值2")
                .retentionPolicy("hour").consistency(ConsistencyLevel.ALL).build();
        // 將兩條記錄添加到batchPoints中
        batchPoints2.point(point2);
        // 將不同的batchPoints序列化后有额，一次性寫(xiě)入數(shù)據(jù)庫(kù)，提高寫(xiě)入速度
        List<String> records = new ArrayList<String>();
        records.add(batchPoints1.lineProtocol());
        records.add(batchPoints2.lineProtocol());
        // 將兩條數(shù)據(jù)批量插入到數(shù)據(jù)庫(kù)中
        influxDBConnection.batchInsert("db-test", "hour", ConsistencyLevel.ALL, records);
    }

方式三：直接調(diào)用write方法寫(xiě)入

@Test
    public void batchWriteTest() {
        Map<String, String> tags = new HashMap<>();
        tags.put("tag1", "tag1");
        tags.put("tag2", "tag2");

        Map<String, Object> fields1 = new HashMap<>();
        fields1.put("field1", "abc");
        fields1.put("field2", 123456);

        Map<String, Object> fields2 = new HashMap<>();
        fields2.put("field1", "bcd");
        fields2.put("field2", 333333);

        Map<String, Object> fields3 = new HashMap<>();
        fields3.put("field1", "efs");
        fields3.put("field2", 444444);

        // 偽造1W條待插入的測(cè)試數(shù)據(jù)
        List<UniteMetricData> recordList=new ArrayList<>(10000);
        for (int i = 0; i < 10000; ++i) {
            UniteMetricData data = new UniteMetricData(tags, fields1, 1559617445000L + random.nextLong() % 1000);
            recordList.add(data);
        }

        long start = System.currentTimeMillis();
        for (UniteMetricData data : recordList) {
            tsdbService.insert(MEASUREMENT_NAME, TimeUnit.MILLISECONDS, data);
        }
        long end = System.currentTimeMillis();
        System.out.println(String.format("Time used %d ms", end - start));
    }

由于在連接創(chuàng)建時(shí)開(kāi)啟了本地緩存區(qū)彼绷，influxdb會(huì)執(zhí)行異步寫(xiě)入巍佑，經(jīng)過(guò)測(cè)試，批量寫(xiě)入性能不低于上面兩種方式寄悯，且無(wú)需手動(dòng)構(gòu)建BathPonint結(jié)構(gòu)句狼，更加簡(jiǎn)單易用，生產(chǎn)環(huán)境中热某，我們就是使用的這種方式，比較推薦胳螟。

3.4 總結(jié)

本小節(jié)主要介紹了如何使用Java API封裝InfluxDB基本的讀寫(xiě)操作昔馋，希望上述service類能夠在大家首次接入InfluxDB時(shí)提供一些便利。

四糖耸、參考資料

1. Java版InfluxDB工具類