Kafka Streams开发单词计数应用

pom.xml

    4.0.0

    com.kafkaspace
    kafkaWorkspace
    1.0-SNAPSHOT

    
        src/main/scala
        src/test/scala
        
            
                net.alchim31.maven
                scala-maven-plugin
                3.2.2
                
                    
                        
                            compile
                            testCompile
                        
                        
                            
                                -dependencyfile
                                ${project.build.directory}/.scala_dependencies
                            
                        
                    
                
            
            
                org.apache.maven.plugins
                maven-shade-plugin
                2.4.3
                
                    
                        package
                        
                            shade
                        
                        
                            
                                
                                    *:*
                                    
                                        meta-INF/*.SF
                                        meta-INF/*.DSA
                                        meta-INF/*.RSA
                                    
                                
                            
                            
                                
                                    
                                
                            
                        
                    
                
            
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    6
                    6
                
            
        
    


    
    
        2.11.8
        2.7.4
        2.3.2
    
    
        
        
            org.scala-lang
            scala-library
            ${scala.version}
        
        
        
            org.apache.spark
            spark-core_2.11
            ${spark.version}
        
        
        
            org.apache.hadoop
            hadoop-client
            ${hadoop.version}
        
        
            org.apache.spark
            spark-sql_2.11
            2.3.2
        

        
            mysql
            mysql-connector-java
            5.1.46
        
        
            org.apache.kafka
            kafka-clients
            2.0.0
        
        
            org.apache.kafka
            kafka-streams
            2.0.0
        
    

LogProcessor.java

import org.apache.kafka.streams.processor.Processor;
import org.apache.kafka.streams.processor.ProcessorContext;
import java.util.HashMap;

public class LogProcessor implements Processor {
    private ProcessorContext processorContext;
    @Override
    public void init(ProcessorContext processorContext) {
        this.processorContext = processorContext;
    }

    @Override
    public void process(byte[] key, byte[] value) {
        String inputOri = new String(value);
        HashMapmap = new HashMap();
        int times = 1;
        if (inputOri.contains(" ")){
            //截取字段
            String[] words = inputOri.split(" ");
            for (String word:words){
                if (map.containsKey(word)){
                    map.put(word, map.get(word)+1);
                }else {
                    map.put(word, times);
                }
            }
        }
        inputOri = map.toString();
        processorContext.forward(key, inputOri.getBytes());
    }

    @Override
    public void close() {

    }
}

App.java

import org.apache.kafka.streams.KafkaStreams;
import org.apache.kafka.streams.StreamsConfig;
import org.apache.kafka.streams.Topology;
import org.apache.kafka.streams.processor.Processor;
import org.apache.kafka.streams.processor.ProcessorSupplier;

import java.util.Properties;

public class App {
    public static void main(String[] args) {
        //声明来源主题
        String fromTopic = "testStreams1";
        //声明目标主题
        String toTopic = "testStreams2";
        //设置KafkaStreams参数信息
        Properties props = new Properties();
        props.put(StreamsConfig.APPLICATION_ID_CONFIG, "logProcessor");
        props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "hadoop01:9092,hadoop02:9092,hadoop03:9092");
        //实例化StreamsConfig对象
        StreamsConfig config = new StreamsConfig(props);
        //创建拓扑结构
        Topology topology = new Topology();
        //添加处理节点，为源处理节点指定名称和它订阅的主题
        topology.addSource("SOURCE", fromTopic)
                //添加自定义处理节点，指定处理器类和上一节点的名称
                .addProcessor("PROCESSOR", new ProcessorSupplier() {
                    @Override
                    public Processor get() {
                        return new LogProcessor();
                    }
                }, "SOURCE")
                //添加目标处理节点，需要指定目标处理节点和上一节点的名称
                .addSink("SINK", toTopic, "PROCESSOR");
        //实例化KafkaStreams对象
        KafkaStreams streams = new KafkaStreams(topology, config);
        streams.start();
    }
}

各节点启动kafka和zookeeper集群

在hadoop01中创建两个主题

kafka-topics.sh --create 
--topic testStreams1 
--partitions 3 
--replication-factor 2 
--zookeeper hadoop01:2181,hadoop02:2181,hadoop03:2181

kafka-topics.sh --create 
--topic testStreams2 
--partitions 3 
--replication-factor 2 
--zookeeper hadoop01:2181,hadoop02:2181,hadoop03:2181

hadoop01中启动生产者服务

kafka-console-producer.sh 
--broker-list hadoop01:9092,hadoop02:9092,hadoop03:9092 
--topic testStreams1

Hadoop02中启动消费者服务

kafka-console-consumer.sh 
--from-beginning 
--topic testStreams2 
--bootstrap-server hadoop01:9092,hadoop02:9092,hadoop03:9092

运行App.java，在生产者服务中输入内容，统计后将在消费者中输出。