BAEL-1420 - introduction to InfluxDB with Java (#3276)

* BAEL-1420 - introduction to InfluxDB with Java

* BAEL-1420 - removed unused catches. Shorten batch timer.

* BAEL-1420 - add notes to readme.

influxdb/README.md

@@ -0,0 +1,17 @@
+## Influx SDK Tutorial Project
+
+### Relevant Article:
+- [Introduction to using InfluxDB with Java](http://www.baeldung.com/using-influxdb-with-java/)
+
+### Overview
+This Maven project contains the Java code for the article linked above.
+
+### Package Organization
+Java classes for the intro tutorial are in the
+org.baeldung.influxdb package.
+
+
+### Running the tests
+The test class expects an InfluxDB server to be available on localhost, at the default port of 8086 and with the default "admin" credentials.
+
+```

influxdb/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>influxdb</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>influxdb</name>
+    <description>InfluxDB SDK Tutorial</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.influxdb</groupId>
+            <artifactId>influxdb-java</artifactId>
+            <version>${influxdb.sdk.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <!-- Check for the most recent available version: https://projectlombok.org/changelog.html -->
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+
+
+
+    </dependencies>
+
+    <properties>
+        <java.version>1.8</java.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <influxdb.sdk.version>2.8</influxdb.sdk.version>
+        <lombok.version>1.16.18</lombok.version>
+
+    </properties>
+
+</project>

influxdb/src/main/java/com/baeldung/influxdb/MemoryPoint.java

@@ -0,0 +1,28 @@
+package com.baeldung.influxdb;
+
+import lombok.Data;
+import org.influxdb.annotation.Column;
+import org.influxdb.annotation.Measurement;
+
+import java.time.Instant;
+
+@Data
+@Measurement(name = "memory")
+public class MemoryPoint {
+
+    @Column(name = "time")
+    private Instant time;
+
+    @Column(name = "name")
+    private String name;
+
+    @Column(name = "free")
+    private Long free;
+
+    @Column(name = "used")
+    private Long used;
+
+    @Column(name = "buffer")
+    private Long buffer;
+
+}

influxdb/src/test/java/com/baeldung/influxdb/InfluxDBConnectionLiveTest.java

@@ -0,0 +1,179 @@
+package com.baeldung.influxdb;
+
+import lombok.extern.slf4j.Slf4j;
+import org.influxdb.InfluxDB;
+import org.influxdb.InfluxDBFactory;
+import org.influxdb.InfluxDBIOException;
+import org.influxdb.dto.*;
+import org.influxdb.impl.InfluxDBResultMapper;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import static junit.framework.TestCase.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+@Slf4j
+public class InfluxDBConnectionLiveTest {
+
+    @Test
+    public void whenCorrectInfoDatabaseConnects() {
+
+        InfluxDB connection = connectDatabase();
+        assertTrue(pingServer(connection));
+    }
+
+    private InfluxDB connectDatabase() {
+
+        // Connect to database assumed on localhost with default credentials.
+        return  InfluxDBFactory.connect("http://127.0.0.1:8086", "admin", "admin");
+
+    }
+
+    private boolean pingServer(InfluxDB influxDB) {
+        try {
+            // Ping and check for version string
+            Pong response = influxDB.ping();
+            if (response.getVersion().equalsIgnoreCase("unknown")) {
+                log.error("Error pinging server.");
+                return false;
+            } else {
+                log.info("Database version: {}", response.getVersion());
+                return true;
+            }
+        } catch (InfluxDBIOException idbo) {
+            log.error("Exception while pinging database: ", idbo);
+            return false;
+        }
+    }
+
+    @Test
+    public void whenDatabaseCreatedDatabaseChecksOk() {
+
+        InfluxDB connection = connectDatabase();
+
+        // Create "baeldung and check for it
+        connection.createDatabase("baeldung");
+        assertTrue(connection.databaseExists("baeldung"));
+
+        // Verify that nonsense databases are not there
+        assertFalse(connection.databaseExists("foobar"));
+
+        // Drop "baeldung" and check again
+        connection.deleteDatabase("baeldung");
+        assertFalse(connection.databaseExists("baeldung"));
+    }
+
+    @Test
+    public void whenPointsWrittenPointsExists() throws Exception {
+
+        InfluxDB connection = connectDatabase();
+
+        String dbName = "baeldung";
+        connection.createDatabase(dbName);
+
+        // Need a retention policy before we can proceed
+        connection.createRetentionPolicy("defaultPolicy", "baeldung", "30d", 1, true);
+
+        // Since we are doing a batch thread, we need to set this as a default
+        connection.setRetentionPolicy("defaultPolicy");
+
+        // Enable batch mode
+        connection.enableBatch(10, 10, TimeUnit.MILLISECONDS);
+
+        for (int i = 0; i < 10; i++) {
+            Point point = Point.measurement("memory")
+                    .time(System.currentTimeMillis(), TimeUnit.MILLISECONDS)
+                    .addField("name", "server1")
+                    .addField("free", 4743656L)
+                    .addField("used", 1015096L)
+                    .addField("buffer", 1010467L)
+                    .build();
+
+            connection.write(dbName, "defaultPolicy", point);
+            Thread.sleep(2);
+
+        }
+
+        // Unfortunately, the sleep inside the loop doesn't always add enough time to insure
+        // that Influx's batch thread flushes all of the writes and this sometimes fails without
+        // another brief pause.
+        Thread.sleep(10);
+
+        List<MemoryPoint> memoryPointList = getPoints(connection, "Select * from memory", "baeldung");
+
+        assertEquals(10, memoryPointList.size());
+
+        // Turn off batch and clean up
+        connection.disableBatch();
+        connection.deleteDatabase("baeldung");
+        connection.close();
+
+    }
+
+    private List<MemoryPoint> getPoints(InfluxDB connection, String query, String databaseName) {
+
+        // Run the query
+        Query queryObject = new Query(query, databaseName);
+        QueryResult queryResult = connection.query(queryObject);
+
+        // Map it
+        InfluxDBResultMapper resultMapper = new InfluxDBResultMapper();
+        return resultMapper.toPOJO(queryResult, MemoryPoint.class);
+    }
+
+
+
+    @Test
+    public void whenBatchWrittenBatchExists() {
+
+        InfluxDB connection = connectDatabase();
+
+        String dbName = "baeldung";
+        connection.createDatabase(dbName);
+
+        // Need a retention policy before we can proceed
+        // Since we are doing batches, we need not set it
+        connection.createRetentionPolicy("defaultPolicy", "baeldung", "30d", 1, true);
+
+
+        BatchPoints batchPoints = BatchPoints
+                .database(dbName)
+                .retentionPolicy("defaultPolicy")
+                .build();
+        Point point1 = Point.measurement("memory")
+                .time(System.currentTimeMillis(), TimeUnit.MILLISECONDS)
+                .addField("free", 4743656L)
+                .addField("used", 1015096L)
+                .addField("buffer", 1010467L)
+                .build();
+        Point point2 = Point.measurement("memory")
+                .time(System.currentTimeMillis() - 100, TimeUnit.MILLISECONDS)
+                .addField("free", 4743696L)
+                .addField("used", 1016096L)
+                .addField("buffer", 1008467L)
+                .build();
+        batchPoints.point(point1);
+        batchPoints.point(point2);
+        connection.write(batchPoints);
+
+        List<MemoryPoint> memoryPointList = getPoints(connection, "Select * from memory", "baeldung");
+
+        assertEquals(2, memoryPointList.size());
+        assertTrue(4743696L == memoryPointList.get(0).getFree());
+
+
+        memoryPointList = getPoints(connection, "Select * from memory order by time desc", "baeldung");
+
+        assertEquals(2, memoryPointList.size());
+        assertTrue(4743656L == memoryPointList.get(0).getFree());
+
+        // Clean up database
+        connection.deleteDatabase("baeldung");
+        connection.close();
+    }
+
+}

influxdb/src/test/resources/logback.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

pom.xml

@@ -80,6 +80,7 @@
 
         <module>image-processing</module>
         <module>immutables</module>
+        <module>influxdb</module>
 
         <module>jackson</module>
         <!--         <module>persistence-modules/java-cassandra</module> -->