flink 使用processFunction函数的sideOutPut实现filter操作(java版)

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
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.functions.ProcessFunction;
import org.apache.flink.util.Collector;
import org.apache.flink.util.OutputTag;

/**
 * # _*_ coding:utf-8 _*_
 * # Author:xiaoshubiao
 * # Time : 2020/12/14 19:14
 **/
public class processFunction_test {
    public static void main(String[] args) throws Exception{
        StreamExecutionEnvironment executionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment();

        DataStreamSource<String> localhost = executionEnvironment.socketTextStream("localhost", 1111);
        // 输入a,1这样的数据，通过ProcessFunction的sideOutPut实现filter的操作
        // 区分是否属于a
        SingleOutputStreamOperator<Tuple2<String, Integer>> map = localhost.map(
                new MapFunction<String, Tuple2<String, Integer>>() {
                    @Override
                    public Tuple2<String, Integer> map(String s) throws Exception {
                        String[] split = s.split(",");
                        return new Tuple2<>(split[0], Integer.valueOf(split[1]));
                    }
                }
        );

        SingleOutputStreamOperator<String> process = map.process(
                /*
                *参数一：输入数据类型。比如(a,1)
                * 参数二：输出数据类型。比如(属于a)
                * */
                new ProcessFunction<Tuple2<String, Integer>, String>() {
                    @Override
                    public void processElement(Tuple2<String, Integer> stringIntegerTuple2, Context context, Collector<String> collector) throws Exception {

                        if (stringIntegerTuple2.f0.equals("a")) {
                            // 直接返回
                            collector.collect("属于a");
                        } else {
                            // 通过上下文输出，定义输出标签和值
                            context.output(new OutputTag<String>("is_not_a"){}, "不属于a");
                        }
                    }
                }
        );
        process.print("is_a");
        process.getSideOutput(new OutputTag<String>("is_not_a"){}).print("is_not_a");

        executionEnvironment.execute();
    }
}
/*
* 输入      输出
* a,1       属于a
* b,1       不属于a
* c,1       不属于a
*
*
* */