一、环境版本
| 环境 | 版本 |
|---|---|
| Flink | 1.17.0 |
| Kafka | 2.12 |
| MySQL | 5.7.33 |
二、MySQL建表脚本
create table user_log
(id int auto_increment comment '主键'primary key,uid int not null comment '用户id',event int not null comment '用户行为',logtime bigint null comment '日志时间'
)comment '用户日志表，作为验证数据源';
三、用户日志类
新建maven项目
用以定义Kafka和MySQL中Schema
/*** 用户日志类*/
@Data
public class UserLog {//用户uidprivate int uid;//用户行为private int event;//日志时间private Date logtime;
}
四、用户数据生成器
/*** 用户数据生成器*/
public class UserLogGenerator {public static void main(String[] args) throws Exception {// 1.获取执行环境StreamExecutionEnvironment env =StreamExecutionEnvironment.getExecutionEnvironment();env.setParallelism(1);// 2.自定义数据生成器SourceDataGeneratorSource<UserLog> dataGeneratorSource = new DataGeneratorSource<>(// 指定GeneratorFunction 实现类new GeneratorFunction<Long, UserLog>(){// 定义随机数数据生成器public RandomDataGenerator generator;@Overridepublic void open(SourceReaderContext readerContext) throws Exception {generator = new RandomDataGenerator();}@Overridepublic UserLog map(Long aLong) throws Exception {UserLog userLog = new UserLog();//随机生成用户uiduserLog.setUid(generator.nextInt(1, 100000));//随机生成用户行为userLog.setEvent(generator.nextInt(1, 2));//随机生成用户数据时间userLog.setLogtime(DateUtil.offset(new DateTime(), DateField.MILLISECOND, generator.nextInt(-2000, 2000)));return userLog;}},// 指定输出数据的总行数60 * 60 * 10,// 指定每秒发射的记录数RateLimiterStrategy.perSecond(10),// 指定返回值类型， 将Java的StockPrice封装成到TypeInformationTypeInformation.of(UserLog.class));DataStreamSource<UserLog> dataGeneratorSourceStream = env.fromSource(dataGeneratorSource, WatermarkStrategy.noWatermarks(), "dataGeneratorSource");//输出生成数据
// dataGeneratorSourceStream.print();//kafka数据写入KafkaSink<UserLog> kafkaSink = KafkaSink.<UserLog>builder().setBootstrapServers("hadoop01:9092").setRecordSerializer(KafkaRecordSerializationSchema.<UserLog>builder().setTopic("userLog").setValueSerializationSchema((SerializationSchema<UserLog>) userLog -> JSONUtil.toJsonStr(userLog).getBytes()).build()).build();dataGeneratorSourceStream.sinkTo(kafkaSink);//MySQL数据写入，用以数据验证SinkFunction<UserLog> jdbcSink = JdbcSink.sink("insert into user_log (uid, event, logtime) values (?, ?, ?)",new JdbcStatementBuilder<UserLog>() {@Overridepublic void accept(PreparedStatement preparedStatement, UserLog userLog) throws SQLException {preparedStatement.setInt(1, userLog.getUid());preparedStatement.setInt(2, userLog.getEvent());preparedStatement.setLong(3, userLog.getLogtime().getTime());}},JdbcExecutionOptions.builder().withBatchSize(1000).withBatchIntervalMs(200).withMaxRetries(5).build(),new JdbcConnectionOptions.JdbcConnectionOptionsBuilder().withUrl("jdbc:mysql://localhost:3306/demo").withDriverName("com.mysql.cj.jdbc.Driver").withUsername("你的用户名").withPassword("你的密码").build());dataGeneratorSourceStream.addSink(jdbcSink);env.execute();}
}
五、TableAPI 10秒钟内用户的访问量
/*** 10秒钟内用户的访问量*/
public class UserLogCount {public static void main(String[] args) throws Exception {StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);env.setParallelism(1);//1.定义table的schemafinal Schema schema = Schema.newBuilder().column("uid", DataTypes.INT()).column("event", DataTypes.INT()).column("logtime", DataTypes.BIGINT())//将logtime转换为flink使用的timsstamp格式.columnByExpression("rowtime", "TO_TIMESTAMP_LTZ(logtime, 3)")//定义水位线.watermark("rowtime", "rowtime - INTERVAL '5' SECOND").build();//2.创建Kafka source tabletableEnv.createTable("user_log", TableDescriptor.forConnector("kafka").schema(schema).format("json")
// .option("json.timestamp-format.standard", "ISO-8601").option("json.ignore-parse-errors", "true").option("topic", "userLog").option("properties.bootstrap.servers", "hadoop01:9092").option("scan.startup.mode", "latest-offset").build());//3.创建一个滚动窗口表Table pvTable = tableEnv.from("user_log")//定义一个10秒钟的滚动窗口.window(Tumble.over(lit(10).seconds()).on($("rowtime")).as("w")).groupBy($("w")).select($("w").start().as("w_start"),$("w").end().as("w_end"),//$("uid").count().distinct().as("uv")),$("uid").count().as("pv"));pvTable.execute().print();}
}
六、数据验证
- 启动 UserLogGenerator
- 启动 UserLogCount
+----+-------------------------+-------------------------+----------------------+
| op | w_start | w_end | pv |
+----+-------------------------+-------------------------+----------------------+
| +I | 2025-08-11 15:11:50.000 | 2025-08-11 15:12:00.000 | 10 |
| +I | 2025-08-11 15:12:00.000 | 2025-08-11 15:12:10.000 | 95 |
| +I | 2025-08-11 15:12:10.000 | 2025-08-11 15:12:20.000 | 104 |
| +I | 2025-08-11 15:12:20.000 | 2025-08-11 15:12:30.000 | 104 |
| +I | 2025-08-11 15:12:30.000 | 2025-08-11 15:12:40.000 | 94 |
| +I | 2025-08-11 15:12:40.000 | 2025-08-11 15:12:50.000 | 104 |
| +I | 2025-08-11 15:12:50.000 | 2025-08-11 15:13:00.000 | 96 |
| +I | 2025-08-11 15:13:00.000 | 2025-08-11 15:13:10.000 | 100 |
- 在MySQL中验证查询
选取数据
+----+-------------------------+-------------------------+----------------------+
| op | w_start | w_end | pv |
+----+-------------------------+-------------------------+----------------------+
| +I | 2025-08-11 15:12:50.000 | 2025-08-11 15:13:00.000 | 96
转换时间戳
| 时间戳 | 转换前 | 转换后 |
|---|---|---|
| w_start | 2025-08-11 15:12:50.000 | 1754896370000 |
| w_end | 2025-08-11 15:13:00.000 | 1754896380000 |
MySQL中查询
# 输出96与Flink结果一致
select count(*)
from user_log
where logtime>= 1754896370000 and logtime < 1754896380000;
七、POM文件
<project><groupId>dblab</groupId><artifactId>demo</artifactId><modelVersion>4.0.0</modelVersion><name> </name><packaging>jar</packaging><version>1.0</version><repositories><repository><id>central-repos</id><name>Central Repository</name><url>http://repo.maven.apache.org/maven2</url></repository><repository><id>alimaven</id><name>aliyun maven</name><url>https://maven.aliyun.com/nexus/content/groups/public/</url></repository></repositories><properties><flink.version>1.17.0</flink.version></properties><dependencies><dependency><groupId>org.apache.flink</groupId><artifactId>flink-streaming-java</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-clients</artifactId><version>${flink.version}</version></dependency>
<!-- <dependency>-->
<!-- <groupId>org.apache.flink</groupId>-->
<!-- <artifactId>flink-connector-files</artifactId>-->
<!-- <version>${flink.version}</version>-->
<!-- </dependency>--><dependency><groupId>org.apache.flink</groupId><artifactId>flink-connector-kafka</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-connector-datagen</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-api-java-bridge</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-planner-loader</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-runtime</artifactId><version>${flink.version}</version></dependency>
<!-- <dependency>-->
<!-- <groupId>org.apache.flink</groupId>-->
<!-- <artifactId>flink-connector-files</artifactId>-->
<!-- <version>${flink.version}</version>-->
<!-- </dependency>--><dependency><groupId>org.apache.flink</groupId><artifactId>flink-table-common</artifactId><version>${flink.version}</version></dependency>
<!-- <dependency>-->
<!-- <groupId>org.apache.flink</groupId>-->
<!-- <artifactId>flink-csv</artifactId>-->
<!-- <version>${flink.version}</version>-->
<!-- </dependency>--><dependency><groupId>org.apache.flink</groupId><artifactId>flink-connector-jdbc</artifactId><version>3.1.1-1.17</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.33</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-json</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.26</version><scope>provided</scope></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.8.39</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-assembly-plugin</artifactId><version>3.0.0</version><configuration><descriptorRefs><descriptorRef>jar-with-dependencies</descriptorRef></descriptorRefs></configuration><executions><execution><id>make-assembly</id><phase>package</phase><goals><goal>single</goal></goals></execution></executions></plugin></plugins></build>
</project>
八、常见问题
8.1 未定义水位线
Exception in thread "main" org.apache.flink.table.api.ValidationException: A group window expects a time attribute for grouping in a stream environment.at org.apache.flink.table.operations.utils.AggregateOperationFactory.validateStreamTimeAttribute(AggregateOperationFactory.java:327)at org.apache.flink.table.operations.utils.AggregateOperationFactory.validateTimeAttributeType(AggregateOperationFactory.java:307)at org.apache.flink.table.operations.utils.AggregateOperationFactory.getValidatedTimeAttribute(AggregateOperationFactory.java:300)at org.apache.flink.table.operations.utils.AggregateOperationFactory.createResolvedWindow(AggregateOperationFactory.java:265)at org.apache.flink.table.operations.utils.OperationTreeBuilder.windowAggregate(OperationTreeBuilder.java:262)at org.apache.flink.table.api.internal.TableImpl$WindowGroupedTableImpl.select(TableImpl.java:641)at UserLogCount.main(UserLogCount.java:42)
当TableAPI中未定义水位线时，会导致Flink无法识别窗口的时间戳
//定义水位线
.watermark("rowtime", "rowtime - INTERVAL '5' SECOND")
