用flink Datastream实现一个功能，监控mysql的某些表，这些表动态添加，通过upsert方式写入Kafka-Go服务器开发

下面是一个使用 Flink DataStream 监控 MySQL 表并将数据以 upsert 方式写入 Kafka 的示例代码：

import org.apache.flink.api.common.serialization.SimpleStringSchema;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.source.RichSourceFunction;
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer;
import org.apache.flink.streaming.util.serialization.JSONKeyValueDeserializationSchema;

import java.sql.*;
import java.util.HashMap;
import java.util.Map;

public class MySQLTableMonitor {

    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // 设置Kafka相关配置
        String kafkaBootstrapServers = "localhost:9092";
        String kafkaTopic = "my_topic";

        // 添加自定义的MySQL监控源
        DataStream<Tuple2<String, Map<String, Object>>> mysqlDataStream = env.addSource(new MySQLTableSource());

        // 使用upsert模式写入Kafka
        mysqlDataStream.addSink(new FlinkKafkaProducer<>(kafkaBootstrapServers,
                kafkaTopic,
                new JSONKeyValueDeserializationSchema(true),
                new SimpleStringSchema()));

        env.execute("MySQL Table Monitor");
    }

    // 自定义MySQL监控源
    public static class MySQLTableSource extends RichSourceFunction<Tuple2<String, Map<String, Object>>>> {

        private Connection connection;
        private Statement statement;

        @Override
        public void open(Configuration parameters) throws Exception {
            super.open(parameters);

            // 连接到MySQL数据库
            Class.forName("com.mysql.jdbc.Driver");
            String url = "jdbc:mysql://localhost:3306/my_database";
            String username = "my_user";
            String password = "my_password";
            connection = DriverManager.getConnection(url, username, password);

            // 创建Statement对象
            statement = connection.createStatement();
        }

        @Override
        public void run(SourceContext<Tuple2<String, Map<String, Object>>> ctx) throws Exception {
            while (true) {
                // 查询MySQL表，这里假设要监控的表名是table1和table2
                String[] tables = {"table1", "table2"};

                for (String table : tables) {
                    ResultSet resultSet = statement.executeQuery("SELECT * FROM " + table);
                    ResultSetMetaData metaData = resultSet.getMetaData();
                    int columnCount = metaData.getColumnCount();

                    while (resultSet.next()) {
                        Map<String, Object> rowMap = new HashMap<>();
                        for (int i = 1; i <= columnCount; i++) {
                            String columnName = metaData.getColumnLabel(i);
                            Object value = resultSet.getObject(i);
                            rowMap.put(columnName, value);
                        }
                        ctx.collect(new Tuple2<>(table, rowMap));
                    }

                    resultSet.close();
                }

                Thread.sleep(5000); // 每隔5秒查询一次

            }
        }

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

在代码中，需要修改以下部分：