Flink Process Function未将数据返回到Sideoutputstream

Question

我正在尝试使用一组规则验证JSONObject，如果json与一组规则匹配，是它将返回匹配的规则，而如果JSON与否，它将返回一个JSONObject到Sideoutput，所有这些都在ProcessFuntion中处理，我正在获取主要输出但无法捕获侧面输出

SideOutput流的定义如下

public final static OutputTag<org.json.JSONObject> unMatchedJSONSideOutput = new OutputTag<org.json.JSONObject>(
            "unmatched-side-output") {};

ProcessFunction定义如下

public class RuleFilter extends ProcessFunction<Tuple2<String,org.json.JSONObject>,Tuple2<String,org.json.JSONObject>> {
@Override
    public void processElement(Tuple2<String, org.json.JSONObject> value,
            ProcessFunction<Tuple2<String, org.json.JSONObject>, Tuple2<String, org.json.JSONObject>>.Context ctx,
            Collector<Tuple2<String, org.json.JSONObject>> out) throws Exception {

        if(this.value.matches((value.f1))) {
        out.collect(new Tuple2<String, org.json.JSONObject>(value.f0,value.f1));
        }else {
            ctx.output(RuleMatching.unMatchedJSONSideOutput,value.f1);
        }
    }
}

我正在打印主要的数据流输出，如下所示

    DataStream<Tuple2<String, org.json.JSONObject>> matchedJSON =
                            inputSignal.map(new MapFunction<org.json.JSONObject, Tuple2<String, org.json.JSONObject>>() {
                                @Override
                                public Tuple2<String, org.json.JSONObject> map(org.json.JSONObject input) throws Exception {
                                    return new Tuple2<>(value, input);
                                }
                            }).process(new RuleFilter()).print("MatchedJSON=>");

matchedJSON .print("matchedJSON=>");

我正在打印如下的Sideoutput

DataStream<org.json.JSONObject> unmatchedJSON =
                        ((SingleOutputStreamOperator<org.json.JSONObject>) matchedJSON.map(new MapFunction<Tuple2<String, org.json.JSONObject>, org.json.JSONObject>() {
                            @Override
                            public org.json.JSONObject map(Tuple2<String, org.json.JSONObject> value) throws Exception {
                                return value.f1;
                            }
                        })).getSideOutput(unMatchedJSONSideOutput );

                unmatchedJSON.print("unmatchedJSON=>");

主流正在打印输出，但是sideoutput没有为无效的json打印，请帮助解决问题

Answer 1

问题在这里：

DataStream<org.json.JSONObject> unmatchedJSON =
    ((SingleOutputStreamOperator<org.json.JSONObject>) matchedJSON.map(...))
    .getSideOutput(unMatchedJSONSideOutput);

您应该直接在getSideOutput上调用matchedJSON，而不是在对其施加MapFunction的结果上。仅ProcessFunction可以有侧面输出，它需要直接来自ProcessFunction。您欺骗了编译器通过从映射强制转换输出流来接受此操作，但是运行时对此无能为力。