flnkcdc+datastream实现mysql到mysql数据同步

一、maven依赖

<dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-clients</artifactId>
            <version>1.18.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-java</artifactId>
            <version>1.18.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-runtime-web</artifactId>
            <version>1.18.1</version>
        </dependency>

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-table-planner_2.12</artifactId>
            <version>1.18.1</version>
            <!--            <scope>provided</scope>-->
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-jdbc</artifactId>
            <version>3.1.2-1.18</version>
            <!--            <scope>provided</scope>-->
            <!--            此标签会移除jar包，当需要打包到集群运行时加上此标签-->
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.29</version>
            <!--            <scope>provided</scope>-->
        </dependency>

二、MysqlReader

package com.example.flinkcdcjob.dataBatch;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.source.RichSourceFunction;

import java.lang.reflect.Field;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class MysqlReader extends RichSourceFunction<List<User>> {
    private Connection connection = null;
    private PreparedStatement ps = null;

    @Override
    public void open(Configuration parameters) throws Exception {
        super.open(parameters);
        Class.forName("com.mysql.cj.jdbc.Driver");//加载数据库驱动
        connection = DriverManager.getConnection("jdbc:mysql://rm-cn-lbj3n5u3s000ap3o.rwlb.rds.aliyuncs.com:3306", "dengxiaohui", "DdXxHh@123321");//获取连接
        ps = connection.prepareStatement("select id,username,password from test_db.user");
    }

    @Override
    public void run(SourceContext<List<User>> sourceContext) throws Exception {
        ResultSet resultSet = ps.executeQuery();//执行sql并返回结果集
        List<User> userList = new ArrayList<>();
        User user = User.class.newInstance();
        int count = 0;
        while (resultSet.next()) {
            User object = new User();
            ResultSetMetaData metaData = resultSet.getMetaData();
            int columnCount = metaData.getColumnCount();
            for (int i = 0; i < columnCount; i++) {
                String columnName = metaData.getColumnName(i + 1);
                Field declaredField = user.getClass().getDeclaredField(columnName);
                declaredField.setAccessible(true);
                if (null != resultSet.getObject(columnName) && !(resultSet.getObject(columnName).toString()).isEmpty()) {
                    declaredField.set(object, resultSet.getObject(columnName));
                } else {
                    declaredField.set(object, null);
                }
            }
            userList.add(object);
            count++;
            if (count % 5000 == 0) {
                sourceContext.collect(userList);
                userList.clear();
            }
        }
        System.out.println("目标表读取数据条数：" + count);
        sourceContext.collect(userList);
    }

    @Override
    public void cancel() {
        try {
            super.close();
            if (connection != null) {
                connection.close();
            }
            if (ps != null) {
                ps.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

三、MyWriter.java

package com.example.flinkcdcjob.dataBatch;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.sink.RichSinkFunction;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

public class MysqlWriter extends RichSinkFunction<List<User>> {

    private Connection connection = null;
    private PreparedStatement preparedStatement = null;
    private int totalNum = 0;

    @Override
    public void open(Configuration parameters) throws Exception {
        super.open(parameters);
        if (connection == null) {
            Class.forName("com.mysql.cj.jdbc.Driver");//加载数据库驱动
            connection = DriverManager.getConnection("jdbc:mysql://rm-cn-lbj3n5u3s000ap3o.rwlb.rds.aliyuncs.com:3306", "dengxiaohui", "DdXxHh@123321");//获取连接
            connection.setAutoCommit(false);//关闭自动提交
        }
        connection.prepareStatement("truncate table sink_db.user").execute(); // 清空目标表数据
        preparedStatement = connection.prepareStatement("insert into sink_db.user values (?,?,?)");
    }

//    @Override
//    public void invoke(Tuple3<Integer, String, String> value, Context context) throws Exception {
//        //获取JdbcReader发送过来的结果
//        try {
//            ps.setInt(1, value.f0);
//            ps.setString(2, value.f1);
//            ps.setString(3, value.f2);
//            ps.executeUpdate();
//        } catch (Exception e) {
//            e.printStackTrace();
//        }
//    }


    @Override
    public void invoke(List<User> value, Context context) throws Exception {
        //获取JdbcReader发送过来的结果
        try {
            for (int i = 0; i < value.size(); i++) {
                Field[] fields = value.get(i).getClass().getDeclaredFields();
                int location = 0;
                for (Field field : fields) {
                    location++;
                    field.setAccessible(true);
                    if (null != (field.get(value.get(i))) && !(field.get(value.get(i)).toString()).isEmpty()) {
                        preparedStatement.setObject(location, (field.get(value.get(i))));
                    } else {
                        preparedStatement.setObject(location, null);
                    }
                }
                preparedStatement.addBatch();
                totalNum++;
            }
            preparedStatement.executeBatch();
            preparedStatement.clearBatch();
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            System.out.println("now time is :" + simpleDateFormat.format(new Date()) + "批量插入数据条数：" + totalNum);
            connection.commit();//预处理完成后统一提交
        } catch (
                Exception e) {
            e.printStackTrace();
        }

    }

    @Override
    public void close() throws Exception {
        super.close();
        if (preparedStatement != null) {
            preparedStatement.close();
        }
        if (connection != null) {
            connection.close();
        }
        super.close();
    }

}

四、数据表对应的实体类 User.java

package com.example.flinkcdcjob.dataBatch;

import lombok.Data;

import java.math.BigInteger;

@Data
public class User {
    public BigInteger id;
    public String username;
    public String password;
}

五、主类MysqlCdcMysql.java

package com.example.flinkcdcjob.dataBatch;

import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;

import java.util.List;

public class MysqlCdcMysql {
    public static void main(String[] args) throws Exception {

        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment().setParallelism(1);
        // 最好不要在程序设置并行度 如果设置了8 要保证安装的flink配置里面的parallelism这个参数大于8 不然会导致资源异常
        // env.setParallelism(8);
        //DataStreamSource<Tuple3<Integer, String, String>> dataStream = env.addSource(new MysqlReader());
        DataStreamSource<List<User>> dataStream = env.addSource(new MysqlReader());
        dataStream.addSink(new MysqlWriter());
        //DataStreamSource<Tuple3<Integer, String, String>> dataStream = env.addSource(new MysqlReader());
        //dataStream.addSink(new MysqlWriter());
        env.execute("Flink cost MySQL data to write MySQL");
    }
}