Flink 系例 之 Process

process算子：处理每个keyBy（分区）输入到窗口的批量数据流（为KeyedStream类型数据流）

示例环境

java.version: 1.8.x
flink.version: 1.11.1

示例数据源 （项目码云下载）

Flink 系例 之 搭建开发环境与数据

Process.java

import com.flink.examples.DataSource;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
import org.apache.flink.streaming.api.windowing.windows.GlobalWindow;
import org.apache.flink.util.Collector;
import java.util.Iterator;
import java.util.List;

public class Process {

    
    public static void main(String[] args) throws Exception {
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        List> tuple3List = DataSource.getTuple3ToList();
        DataStream dataStream = env.fromCollection(tuple3List)
                .keyBy((KeySelector, String>) k -> k.f1)
                //按数量窗口滚动，每3个输入数据流，计算一次
                .countWindow(3)
                //处理每keyBy后的窗口数据流，process方法通常应用于KeyedStream类型的数据流处理
                .process(new ProcessWindowFunction, String, String, GlobalWindow>() {
                    
                    @Override
                    public void process(String s, Context context, Iterable> input, Collector out) throws Exception {
                        Iterator> iterator = input.iterator();
                        int total = 0;
                        int i = 0;
                        while (iterator.hasNext()){
                            Tuple3 tuple3 = iterator.next();
                            total += tuple3.f2;
                            i ++ ;
                        }
                        out.collect(s + "共:"+i+"人，平均年龄：" + total/i);
                    }
                });
        dataStream.print();
        env.execute("flink Process job");
    }
}

打印结果

4> girl共:3人，平均年龄：24
2> man共:3人，平均年龄：26