Flink SQL/Table API 消费Kafka数据并存入MySQL（通过JDBCAppendTableSink方式来实现存入到MySQL）

[另一篇Flink通过继承RichSinkFunction来实现数据存入MySQL：https://blog.csdn.net/qq_39799876/article/details/91437749 ]

这种方式实现存到MySQL，需要注意一些问题。
另外，需要添加 flink-jdbc 这个依赖。

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.io.jdbc.JDBCAppendTableSink;
import org.apache.flink.streaming.api.TimeCharacteristic;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.TableEnvironment;
import org.apache.flink.table.api.java.StreamTableEnvironment;
import org.apache.flink.table.descriptors.Json;
import org.apache.flink.table.descriptors.Kafka;
import org.apache.flink.table.descriptors.Schema;
import org.apache.flink.types.Row;


public class MainDemo {

    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);
        env.enableCheckpointing(5000);
        env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
        StreamTableEnvironment tableEnv = TableEnvironment.getTableEnvironment(env);

        Kafka kafka = new Kafka()
                .version("0.10")
                .topic("kafka")
                .property("bootstrap.servers", "192.168.219.132:9092")
                .property("zookeeper.connect", "192.168.219.132:2181");
        tableEnv.connect(kafka)
                .withFormat(
                        new Json().failOnMissingField(true).deriveSchema()
                )
                .withSchema(
                        new Schema()
                                .field("id", Types.INT)
                                .field("iname", Types.STRING)
                                .field("sex", Types.STRING)
                                .field("score", Types.INT)//这里定义为float时，会重复消费一条数据，而且不会存到MySQL，像是程序一直死循环在那里了
                )
                .inAppendMode()
                .registerTableSource("test1");

        String query = "select id,iname,sex,score from test1";
        Table result = tableEnv.sqlQuery(query);

        JDBCAppendTableSink sink = JDBCAppendTableSink.builder()
                .setDrivername("com.mysql.jdbc.Driver")
                .setDBUrl("jdbc:mysql://localhost:3306/flink")
                .setUsername("root")
                .setPassword("123456")
                .setParameterTypes(
                        new TypeInformation[] { BasicTypeInfo.INT_TYPE_INFO,BasicTypeInfo.STRING_TYPE_INFO,BasicTypeInfo.STRING_TYPE_INFO,BasicTypeInfo.INT_TYPE_INFO })
                .setQuery("REPLACE INTO test2 (id,iname,sex,score) VALUES(?,?,?,?)")
                .build();

        DataStream stream = tableEnv.toAppendStream(result, Row.class);

        stream.print();
        sink.emitDataStream(stream);

        env.execute();
    }
}

参考：https://ci.apache.org/projects/flink/flink-docs-release-1.7/api/java/