Java Flink與kafka實現實時告警功能過程

<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-java</artifactId>
    <version>1.13.0</version>
</dependency>
<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-streaming-java_2.12</artifactId>
    <version>1.13.0</version>
</dependency>
<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-clients_2.12</artifactId>
    <version>1.13.0</version>
</dependency>
<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-connector-kafka_2.12</artifactId>
    <version>1.13.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.12</version>
    <scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.62</version>
</dependency>
<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-connector-kafka_2.11</artifactId>
    <version>1.10.0</version>
</dependency>

public class StreamAlertDemo {
	public static void main(String[] args) throws Exception {
		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment().setParallelism(3);
		Properties properties = new Properties();
		properties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
		FlinkKafkaConsumer<String> kafkaConsumer = new FlinkKafkaConsumer<>("test", new SimpleStringSchema(), properties);
		DataStreamSource<String> inputDataStream = env.addSource(kafkaConsumer);
		DataStream<String> resultStream = inputDataStream.flatMap(new AlertFlatMapper());
		resultStream.print().setParallelism(4);
		resultStream.addSink(new FlinkKafkaProducer<>("demo",new SimpleStringSchema(),properties));
		env.execute();
	}
}

public class RuleMap {
	private RuleMap(){}
	public final static Map<String,List<AlertRule>> initialRuleMap;
	private static List<AlertRule> ruleList = new ArrayList<>();
	private static List<String> ruleStringList = new ArrayList<>(Arrays.asList(
			"{\"target\":\"MathVal\",\"type\":\"0\",\"criticalVal\":90,\"descInfo\":\"You Math score is too low\"}",
			"{\"target\":\"MathVal\",\"type\":\"2\",\"criticalVal\":140,\"descInfo\":\"You Math score is too high\"}",
			"{\"target\":\"PhysicsVal\",\"type\":\"0\",\"criticalVal\":60,\"descInfo\":\"You Physics score is too low\"}",
			"{\"target\":\"PhysicsVal\",\"type\":\"2\",\"criticalVal\":95,\"descInfo\":\"You Physics score is too high\"}"));
	static {
		for (String i : ruleStringList) {
			ruleList.add(JSON.parseObject(i, AlertRule.class));
		}
		initialRuleMap = ruleList.stream().collect(Collectors.groupingBy(AlertRule::getTarget));
	}
}

public class AlertFlatMapper implements FlatMapFunction<String, String> {
	@Override
	public void flatMap(String inVal, Collector<String> out) throws Exception {
		Achievement user = JSON.parseObject(inVal, Achievement.class);
		Map<String, List<AlertRule>> initialRuleMap = RuleMap.initialRuleMap;
		List<AlertInfo> resList = new ArrayList<>();
		List<AlertRule> mathRule = initialRuleMap.get("MathVal");
		for (AlertRule rule : mathRule) {
			if (checkVal(user.getMathVal(), rule.getCriticalVal(), rule.getType())) {
				resList.add(new AlertInfo(user.getName(), rule.getDescInfo()));
			}
		}
		List<AlertRule> physicsRule = initialRuleMap.get("PhysicsVal");
		for (AlertRule rule : physicsRule) {
			if (checkVal(user.getPhysicsVal(), rule.getCriticalVal(), rule.getType())) {
				resList.add(new AlertInfo(user.getName(), rule.getDescInfo()));
			}
		}
		String result = JSON.toJSONString(resList);
		out.collect(result);
	}
	private static boolean checkVal(Integer actVal, Integer targetVal, Integer type) {
		switch (type) {
			case 0:
				return actVal < targetVal;
			case 1:
				return actVal.equals(targetVal);
			case 2:
				return actVal > targetVal;
			default:
				return false;
		}
	}
}

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class Achievement implements Serializable {
    private static final long serialVersionUID = -1L;
    private String name;
    private Integer mathVal;
    private Integer physicsVal;
}
@Data
@AllArgsConstructor
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class AlertInfo implements Serializable {
    private static final long serialVersionUID = -1L;
    private String name;
    private String descInfo;
}
@Data
@AllArgsConstructor
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class AlertRule implements Serializable {
	private static final long serialVersionUID = -1L;
	private String target;
	//0小於 1等於 2大於
	private Integer type;
	private Integer criticalVal;
	private String descInfo;
}

{"name":"liu","MathVal":45,"PhysicsVal":76}