1、mysql数据库test
2、kafka创建主题student
3、pom.xml
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.3.7.RELEASE</spring-boot.version>
</properties> <dependencies>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-java</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-clients_2.11</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java_2.11</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-connector-jdbc_2.11</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-connector-kafka_2.11</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-scala_2.11</artifactId>
<version>1.10.0</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-runtime-web_2.11</artifactId>
<version>1.9.2</version>
</dependency> <dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.78</version>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.1.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.49</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
4、实体Student
public class Student {
private Integer id;
private String name;
private String password;
private Integer age; public Student(Integer id, String name, String password, Integer age) {
this.id = id;
this.name = name;
this.password = password;
this.age = age;
} public Integer getId() {
return id;
} public void setId(Integer id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getPassword() {
return password;
} public void setPassword(String password) {
this.password = password;
} public Integer getAge() {
return age;
} public void setAge(Integer age) {
this.age = age;
}
}
5、GsonUtil工具类
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import java.lang.reflect.Type;
import java.nio.charset.Charset; public class GsonUtil {
private final static Gson gson = new Gson(); private final static Gson disableHtmlEscapingGson = new GsonBuilder().disableHtmlEscaping().create();
public static <T> T fromJson(String value, Class<T> type) {
return gson.fromJson(value, type);
} public static <T> T fromJson(String value, Type type) {
return gson.fromJson(value, type);
} public static String toJson(Object value) {
return gson.toJson(value);
} public static String toJsonDisableHtmlEscaping(Object value) {
return disableHtmlEscapingGson.toJson(value);
} ｝
6、kafka生产者producer
注:kafka先批量生成student的json数据
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import java.util.Properties;public class KafkaUtil {
public static final String broker_list = "localhost:9094";
public static final String topic = "student"; //kafka topic 需要和 flink 程序用同一个 topic /**
* 往Kafka写入数据
* Student的json串
* 主题topic:student
* @throws InterruptedException
*/
public static void writeToKafka() throws InterruptedException {
Properties props = new Properties();
props.put("bootstrap.servers", broker_list);
props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
KafkaProducer producer = new KafkaProducer<String, String>(props); for (int i = 51; i <= 100; i++) {
Student student = new Student(i, "zhisheng" + i, "password" + i, 18 + i);
ProducerRecord record = new ProducerRecord<String, String>(topic, null, null, GsonUtil.toJson(student));
producer.send(record);
System.out.println("发送数据: " + GsonUtil.toJson(student));
Thread.sleep(10 * 1000); //发送一条数据 sleep 10s，相当于 1 分钟 6 条
}
producer.flush();
} public static void main(String[] args) throws InterruptedException {
writeToKafka();
}
}
7、SinkToMySQL 工具类
注:student数据写入Mysql的student表
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.sink.RichSinkFunction;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.List;
public class SinkToMySQL extends RichSinkFunction<List<Student>> {
PreparedStatement ps;
BasicDataSource dataSource;
private Connection connection;
/**
* open() 方法中建立连接，这样不用每次 invoke 的时候都要建立连接和释放连接
*
* @param parameters
* @throws Exception
*/
@Override
public void open(Configuration parameters) throws Exception {
super.open(parameters);
dataSource = new BasicDataSource();
connection = getConnection(dataSource);
String sql = "insert into Student(id, name, password, age) values(?, ?, ?, ?);";
ps = this.connection.prepareStatement(sql);
}
@Override
public void close() throws Exception {
super.close();
//关闭连接和释放资源
if (connection != null) {
connection.close();
}
if (ps != null) {
ps.close();
}
}
/**
* 每条数据的插入都要调用一次 invoke() 方法
*
* @param value
* @param context
* @throws Exception
*/
@Override
public void invoke(List<Student> value, Context context) throws Exception {
//遍历数据集合
for (Student student : value) {
ps.setInt(1, student.getId());
ps.setString(2, student.getName());
ps.setString(3, student.getPassword());
ps.setInt(4, student.getAge());
ps.addBatch();
}
int[] count = ps.executeBatch();//批量后执行
System.out.println("成功了插入了" + count.length + "行数据");
}
private static Connection getConnection(BasicDataSource dataSource) {
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
//注意，替换成自己本地的 mysql 数据库地址和用户名、密码
dataSource.setUrl("jdbc:mysql://localhost:3306/test");
dataSource.setUsername("root");
dataSource.setPassword("root");
//设置连接池的一些参数
dataSource.setInitialSize(10);
dataSource.setMaxTotal(50);
dataSource.setMinIdle(2);
Connection con = null;
try {
con = dataSource.getConnection();
System.out.println("创建连接池：" + con);
} catch (Exception e) {
System.out.println("-----------mysql get connection has exception , msg = " + e.getMessage());
}
return con;
}
}
8、Main kafka消费者
注:读取kafka并存入Mysql
import org.apache.flink.api.common.serialization.SimpleStringSchema;
import org.apache.flink.shaded.guava18.com.google.common.collect.Lists;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.windowing.AllWindowFunction;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer;
import org.apache.flink.util.Collector;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties; public class Main {
public static void main(String[] args) throws Exception{
final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
Properties props = new Properties();
props.put("bootstrap.servers", "localhost:9094");//kafka
props.put("zookeeper.connect", "localhost:2181");//zk
props.put("group.id", "test");
props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
props.put("auto.offset.reset", "latest");student
FlinkKafkaConsumer<String> consumer=new FlinkKafkaConsumer<String>("student" ,new SimpleStringSchema(),props);
consumer.setStartFromEarliest();//从初始值开始
SingleOutputStreamOperator<Student> studentoso= env.addSource(consumer).setParallelism(1).map(string -> GsonUtil.fromJson(string, Student.class)); //
studentoso.print();
studentoso.timeWindowAll(Time.minutes(1)).apply(new AllWindowFunction<Student, List<Student>, TimeWindow>() {
@Override
public void apply(TimeWindow window, Iterable<Student> values, Collector<List<Student>> out) throws Exception {
ArrayList<Student> students = Lists.newArrayList(values);
if (students.size() > 0) {
System.out.println("1 分钟内收集到 student 的数据条数是：" + students.size());
out.collect(students);
}
}
}).addSink(new SinkToMySQL());//读取Kafka数据{students} 存入Mysqlenv.execute("flink learning connectors kafka");
}
}
9、其他问题
Main kafka消费者 一直提示
一直提示The group coordinator is not available-Kafka
解决把zk 里brokers/toptics 清除一下并重启kafka
