我想用spark文件流应用程序实现checkpoint，以便在spark流应用程序停止/终止时处理hadoop中所有未处理的文件。我遵循这个：流编程指南，但没有找到javastreamingcontextfactory。请帮帮我该怎么办。
我的密码是

public class StartAppWithCheckPoint {

    public static void main(String[] args) {

        try {

            String filePath = "hdfs://Master:9000/mmi_traffic/listenerTransaction/2020/*/*/*/"; 
            String checkpointDirectory = "hdfs://Mongo1:9000/probeAnalysis/checkpoint";
            SparkSession sparkSession = JavaSparkSessionSingleton.getInstance();

            JavaStreamingContextFactory contextFactory = new JavaStreamingContextFactory() {
                  @Override public JavaStreamingContext create() {

                    SparkConf sparkConf = new SparkConf().setAppName("ProbeAnalysis");
                    JavaSparkContext sc = new JavaSparkContext(sparkConf);  
                    JavaStreamingContext jssc = new JavaStreamingContext(sc, Durations.seconds(300));
                    JavaDStream<String> lines = jssc.textFileStream(filePath).cache();

                    jssc.checkpoint(checkpointDirectory);
                    return jssc;
                  }
                };

            JavaStreamingContext context = JavaStreamingContext.getOrCreate(checkpointDirectory, contextFactory);

            context.start();
            context.awaitTermination();
            context.close();
            sparkSession.close();

        } catch(Exception e) {
            e.printStackTrace();
        }   
    }
}