Flink侧流处理延迟数据示例
import cn.guangjun.flink.pojo.Event;
import org.apache.flink.api.common.eventtime.SerializableTimestampAssigner;
import org.apache.flink.api.common.eventtime.WatermarkStrategy;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
import org.apache.flink.streaming.api.windowing.assigners.TumblingEventTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
import org.apache.flink.util.Collector;
import org.apache.flink.util.OutputTag;
import java.time.Duration;
/**
* DataDelayedDemo 类用于演示流处理中的数据延迟情况
*/
public class DataDelayedDemo {
/**
* 主函数,用于设置流处理环境和处理逻辑
* @param args 命令行参数
* @throws Exception 如果处理过程中发生错误,则抛出异常
*/
public static void main(String[] args) throws Exception {
// 获取流处理环境
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
// 设置并行度为1
env.setParallelism(1);
// 从socket接收数据,并转换为Event对象
SingleOutputStreamOperator<Event> map = env.socketTextStream("127.0.0.1", 8888).map(new MapFunction<String, Event>() {
@Override
public Event map(String s) throws Exception {
// 解析接收到的字符串,转换为Event对象
String[] split = s.split(",");
return new Event(split[0], split[1], Integer.parseInt(split[2]),Integer.parseInt(split[3]) );
}
})
// 设置水位线,最大延迟时间为2秒
.assignTimestampsAndWatermarks(WatermarkStrategy.<Event>forBoundedOutOfOrderness(Duration.ofSeconds(2))
.withTimestampAssigner(new SerializableTimestampAssigner<Event>() {
@Override
public long extractTimestamp(Event element, long recordTimestamp) {
// 使用Event对象中的时间戳
return element.getTimeStamp();
}
}));
// 设置侧输出流,用于处理延迟数据
OutputTag<Event> outputTag = new OutputTag<Event>("delayed") {
};
// 按照键进行分组,并设置滚动窗口
SingleOutputStreamOperator<String> aggregate = map.keyBy(data -> true)
.window(TumblingEventTimeWindows.of(Time.seconds(5)))
// 允许的最大延迟时间为1分钟
.allowedLateness(Time.minutes(1))
// 将延迟数据输出到侧输出流
.sideOutputLateData(outputTag)
// 自定义聚合函数和处理窗口函数
.aggregate(new CustomAggregate(), new ProcessWindowFunction<String, String, Boolean, TimeWindow>() {
@Override
public void process(Boolean aBoolean, ProcessWindowFunction<String, String, Boolean, TimeWindow>.Context context, Iterable<String> elements, Collector<String> out) throws Exception {
// 获取当前窗口的起始和结束时间
Long start = context.window().getStart();
Long end = context.window().getEnd();
// 输出聚合结果
out.collect(elements.iterator().next());
// 打印当前窗口信息
System.out.println("【当前窗口】[" + start + ":" + end + ")");
}
});
// 打印主输出流的结果
aggregate.print("result");
// 打印侧输出流的结果
aggregate.getSideOutput(outputTag).print("side_out_put");
// 执行流处理任务
env.execute();
}
}