目录

案例三 会话窗口

需求

代码实现

案例三 会话窗口

需求

设置会话超时时间为10s,10s内没有数据到来,则触发上个窗口的计算

​​​​​​​代码实现

  

   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      package cn.itcast.window;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import lombok.AllArgsConstructor;
     
    
   

    

     

    
    

     

      import lombok.Data;
     
    
   

    

     

    
    

     

      import lombok.NoArgsConstructor;
     
    
   

    

     

    
    

     

      import org.apache.flink.api.common.functions.MapFunction;
     
    
   

    

     

    
    

     

      import org.apache.flink.streaming.api.datastream.DataStreamSource;
     
    
   

    

     

    
    

     

      import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
     
    
   

    

     

    
    

     

      import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
     
    
   

    

     

    
    

     

      import org.apache.flink.streaming.api.windowing.assigners.ProcessingTimeSessionWindows;
     
    
   

    

     

    
    

     

      import org.apache.flink.streaming.api.windowing.time.Time;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      /**
     
    
   

    

     

    
    

     

       * Author itcast
     
    
   

    

     

    
    

     

       * Desc
     
    
   

    

     

    
    

     

       * nc -lk 9999
     
    
   

    

     

    
    

     

       * 有如下数据表示:
     
    
   

    

     

    
    

     

       * 信号灯编号和通过该信号灯的车的数量
     
    
   

    

     

    
    

     

      9,3
     
    
   

    

     

    
    

     

      9,2
     
    
   

    

     

    
    

     

      9,7
     
    
   

    

     

    
    

     

      4,9
     
    
   

    

     

    
    

     

      2,6
     
    
   

    

     

    
    

     

      1,5
     
    
   

    

     

    
    

     

      2,3
     
    
   

    

     

    
    

     

      5,7
     
    
   

    

     

    
    

     

      5,4
     
    
   

    

     

    
    

     

       * 需求:设置会话超时时间为10s,10s内没有数据到来,则触发上个窗口的计算(前提是上一个窗口得有数据!)
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     

      public class WindowDemo03_SessionWindow {
     
    
   

    

     

    
    

     

          public static void main(String[] args) throws Exception {
     
    
   

    

     

    
    

     

              //1.env
     
    
   

    

     

    
    

     

              StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
     
    
   

    

     

    
    

     

              //2.Source
     
    
   

    

     

    
    

     

              DataStreamSource<String> socketDS = env.socketTextStream("node1", 9999);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              //3.Transformation
     
    
   

    

     

    
    

     

              //将9,3转为CartInfo(9,3)
     
    
   

    

     

    
    

     

              SingleOutputStreamOperator<CartInfo> cartInfoDS = socketDS.map(new MapFunction<String, CartInfo>() {
     
    
   

    

     

    
    

     

                  @Override
     
    
   

    

     

    
    

     

                  public CartInfo map(String value) throws Exception {
     
    
   

    

     

    
    

     

                      String[] arr = value.split(",");
     
    
   

    

     

    
    

     

                      return new CartInfo(arr[0], Integer.parseInt(arr[1]));
     
    
   

    

     

    
    

     

                  }
     
    
   

    

     

    
    

     

              });
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              //需求:设置会话超时时间为10s,10s内没有数据到来,则触发上个窗口的计算(前提是上一个窗口得有数据!)
     
    
   

    

     

    
    

     

              SingleOutputStreamOperator<CartInfo> result = cartInfoDS.keyBy(CartInfo::getSensorId)
     
    
   

    

     

    
    

     

                      .window(ProcessingTimeSessionWindows.withGap(Time.seconds(10)))
     
    
   

    

     

    
    

     

                      .sum("count");
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              //4.Sink
     
    
   

    

     

    
    

     

              result.print();
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              //5.execute
     
    
   

    

     

    
    

     

              env.execute();
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     

          @Data
     
    
   

    

     

    
    

     

          @AllArgsConstructor
     
    
   

    

     

    
    

     

          @NoArgsConstructor
     
    
   

    

     

    
    

     

          public static class CartInfo {
     
    
   

    

     

    
    

     

              private String sensorId;//信号灯id
     
    
   

    

     

    
    

     

              private Integer count;//通过该信号灯的车的数量
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: lansonli.blog.csdn.net，作者：Lansonli，版权归原作者所有，如需转载，请联系作者。

原文链接：lansonli.blog.csdn.net/article/details/116279229