Java代码实现时的问题

在Scala中

.withTimestampAssigner(new SerializableTimestampAssigner

换在java中实现，调用该方法总是出问题，于是我换作了

DataStream<Tuple2<String, Long>> watermarkStream = inputMap.assignTimestampsAndWatermarks(new AssignerWithPeriodicWatermarks<Tuple2<String, Long>>() {
    Long currentMaxTimestamp = 0L;
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    @Nullable
    @Override
    public Watermark getCurrentWatermark() {
        return new Watermark(currentMaxTimestamp - 10000L);
    }

    @Override
    public long extractTimestamp(Tuple2<String, Long> stringLongTuple2, long l) {
        long timeStamp = stringLongTuple2.f1;
        currentMaxTimestamp = Math.max(currentMaxTimestamp, timeStamp);
        System.out.println("currentMaxTimeStamp: "+sdf.format(currentMaxTimestamp));
        return timeStamp;
    }
});

请问老师如果在java中用SerializableTimestampAssigner的话应该如何操作?

# 具体错误：

好像是泛型引起的