【Flink报错】Could not determine TypeInformation for the OutputTag type.

报错信息：

Exception in thread "main" org.apache.flink.api.common.functions.InvalidTypesException: Could not determine TypeInformation for the OutputTag type. The most common reason is forgetting to make the OutputTag an anonymous inner class. It is also not possible to use generic type variables with OutputTags, such as 'Tuple2<A, B>'.at org.apache.flink.util.OutputTag.<init>(OutputTag.java:68)
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原因分析：

找不到OutputTag 的类型,是由于泛型擦除导致的，我们可以通过匿名内部类的方式解决这个问题.

解决方案：

//定义一个输出标签
        OutputTag<Event> late = new OutputTag<Event>("late");


        SingleOutputStreamOperator<UrlViewCount> result = stream.keyBy(data -> data.url)
                .window(TumblingEventTimeWindows.of(Time.seconds(10)))
                .allowedLateness(Time.minutes(1))
                .sideOutputLateData(late)
                .aggregate(new UrlViewCountAgg(), new UrlViewCountResult());
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//定义一个输出标签
        OutputTag<Event> late = new OutputTag<Event>("late"){};


        SingleOutputStreamOperator<UrlViewCount> result = stream.keyBy(data -> data.url)
                .window(TumblingEventTimeWindows.of(Time.seconds(10)))
                .allowedLateness(Time.minutes(1))
                .sideOutputLateData(late)
                .aggregate(new UrlViewCountAgg(), new UrlViewCountResult());
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只需在代码后面加上大括号即可。