问题

flink版本：1.18.1，mysql版本：8.0.40
使用FlinkCDC的MySqlSource 连接mysql，对于datetime 类型字段，Flink CDC 会自动将 datetime 类型的字段转换为时间戳（BIGINT 类型）。如：2020-10-21 18:49:12 变成 1603306152000

解决

1.自定义转换器类

创建 MyDateToStringConverter 类 实现 CustomConverter 接口，并重写

import io.debezium.spi.converter.CustomConverter;
import io.debezium.spi.converter.RelationalColumn;
import org.apache.kafka.connect.data.SchemaBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.sql.Timestamp;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.Properties;
import java.util.function.Consumer;/*** 日期时间类型转换成字符串*/
public class MyDateToStringConverter implements CustomConverter<SchemaBuilder, RelationalColumn> {private static final Logger log = LoggerFactory.getLogger(MyDateToStringConverter.class);private DateTimeFormatter dateFormatter = DateTimeFormatter.ISO_DATE;private DateTimeFormatter timeFormatter = DateTimeFormatter.ISO_TIME;private DateTimeFormatter datetimeFormatter = DateTimeFormatter.ISO_DATE_TIME;private DateTimeFormatter timestampFormatter = DateTimeFormatter.ISO_DATE_TIME;private ZoneId timestampZoneId = ZoneId.systemDefault();public static final String CONVERTERS = "converters";public static final String DATE = "date";public static final String DATE_TYPE = "date.type";public static final String DATE_FORMAT_DATE = "date.format.date";public static final String DATE_FORMAT_DATETIME = "date.format.datetime";public static final String DATE_FORMAT_TIMESTAMP = "date.format.timestamp";public static final String DATE_FORMAT_TIMESTAMP_ZONE = "date.format.timestamp.zone";public static final String YEAR_MONTH_DAY_FORMAT = "yyyy-MM-dd";public static final String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";public static final String DATETIME_MICRO_FORMAT = "yyyy-MM-dd HH:mm:ss.SSSSSS";public static final String TIME_ZONE_SHANGHAI = "Asia/Shanghai";public static final String TIME_ZONE_UTC_8 = "UTC+8";public static final String FORMAT_DATE = "format.date";public static final String FORMAT_TIME = "format.time";public static final String FORMAT_DATETIME = "format.datetime";public static final String FORMAT_TIMESTAMP = "format.timestamp";public static final String FORMAT_TIMESTAMP_ZONE = "format.timestamp.zone";public static final String UPPERCASE_DATE = "DATE";public static final String TIME = "TIME";public static final String DATETIME = "DATETIME";public static final String TIMESTAMP = "TIMESTAMP";public static final String SMALLDATETIME = "SMALLDATETIME";public static final String DATETIME2 = "DATETIME2";public static final Properties DEFAULT_PROPS = new Properties();static {DEFAULT_PROPS.setProperty(CONVERTERS, DATE);DEFAULT_PROPS.setProperty(DATE_TYPE, "com.flink.test.MyDateToStringConverter"); // 需要设置本类的全类名引用，具体根据自己的类设置DEFAULT_PROPS.setProperty(DATE_FORMAT_DATE, YEAR_MONTH_DAY_FORMAT);DEFAULT_PROPS.setProperty(DATE_FORMAT_DATETIME, DATE_TIME_FORMAT);DEFAULT_PROPS.setProperty(DATE_FORMAT_TIMESTAMP, DATE_TIME_FORMAT);DEFAULT_PROPS.setProperty(DATE_FORMAT_TIMESTAMP_ZONE, TIME_ZONE_UTC_8);}@Overridepublic void configure(Properties props) {readProps(props, FORMAT_DATE, p -> dateFormatter = DateTimeFormatter.ofPattern(p));readProps(props, FORMAT_TIME, p -> timeFormatter = DateTimeFormatter.ofPattern(p));readProps(props, FORMAT_DATETIME, p -> datetimeFormatter = DateTimeFormatter.ofPattern(p));readProps(props, FORMAT_TIMESTAMP, p -> timestampFormatter = DateTimeFormatter.ofPattern(p));readProps(props, FORMAT_TIMESTAMP_ZONE, z -> timestampZoneId = ZoneId.of(z));}private void readProps(Properties properties, String settingKey, Consumer<String> callback) {String settingValue = (String) properties.get(settingKey);if (settingValue == null || settingValue.length() == 0) {return;}try {callback.accept(settingValue.trim());} catch (IllegalArgumentException | DateTimeException e) {log.error("setting {} is illegal:{}", settingKey, settingValue);throw e;}}@Overridepublic void converterFor(RelationalColumn column, ConverterRegistration<SchemaBuilder> registration) {String sqlType = column.typeName().toUpperCase();SchemaBuilder schemaBuilder = null;Converter converter = null;if (UPPERCASE_DATE.equals(sqlType)) {schemaBuilder = SchemaBuilder.string().optional();converter = this::convertDate;}if (TIME.equals(sqlType)) {schemaBuilder = SchemaBuilder.string().optional();converter = this::convertTime;}if (DATETIME.equals(sqlType)) {schemaBuilder = SchemaBuilder.string().optional();converter = this::convertDateTime;}if (TIMESTAMP.equals(sqlType)) {schemaBuilder = SchemaBuilder.string().optional();converter = this::convertTimestamp;}if (schemaBuilder != null) {registration.register(schemaBuilder, converter);}}private String convertDate(Object input) {if (input instanceof LocalDate) {return dateFormatter.format((LocalDate) input);} else if (input instanceof Integer) {LocalDate date = LocalDate.ofEpochDay((Integer) input);return dateFormatter.format(date);}return null;}private String convertTime(Object input) {if (input instanceof Duration) {Duration duration = (Duration) input;long seconds = duration.getSeconds();int nano = duration.getNano();LocalTime time = LocalTime.ofSecondOfDay(seconds).withNano(nano);return timeFormatter.format(time);}return null;}private String convertDateTime(Object input) {if (input instanceof LocalDateTime) {return datetimeFormatter.format((LocalDateTime) input);} else if (input instanceof Timestamp) {return datetimeFormatter.format(((Timestamp) input).toLocalDateTime());}return null;}private String convertTimestamp(Object input) {if (input instanceof ZonedDateTime) {// MySQL中的TIMESTAMP数据类型会被转换为UTC时间进行存储，//而在程序中处理这个zonedDatetime时，它表示的是UTC时间ZonedDateTime zonedDateTime = (ZonedDateTime) input;LocalDateTime localDateTime =zonedDateTime.withZoneSameInstant(timestampZoneId).toLocalDateTime();return timestampFormatter.format(localDateTime);} else if (input instanceof Timestamp) {return timestampFormatter.format(((Timestamp) input).toInstant().atZone(timestampZoneId).toLocalDateTime());}return null;}
}

2.代码引用

//获取Flink执行环境StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();env.setParallelism(2);// 连接mysqlMySqlSource<String> mySqlSource = MySqlSource.<String>builder().hostname("junbo-bigdata01").port(3306).username("root").password("123456").databaseList("gmall").tableList("gmall.activity_info").startupOptions(StartupOptions.initial()).deserializer(new JsonDebeziumDeserializationSchema()).serverTimeZone("Asia/Shanghai").includeSchemaChanges(true)// 日期时间类型转换成字符串 的设置引用.debeziumProperties(MyDateToStringConverter.DEFAULT_PROPS) .build();//读取数据DataStreamSource<String> mysqlDS = env.fromSource(mySqlSource,WatermarkStrategy.noWatermarks(), "mysql-source");dataStreamSource.print();env.execute();

结果

datetime 类型 成功转换成 字符串 类型