fix error

src/main/scala/com/aliyun/odps/spark/examples/makedata_recsys/video_dssm_sampler.scala

@@ -85,11 +85,7 @@ object video_dssm_sampler {
   }
 
 
-  // 3. 定义UDF函数来生成负样本
-  def generateNegativeVidsUDF = udf((vid_left: String, vid_right: String) => {
-    val negativeVids = Random.shuffle(allVids - vid_left - vid_right).take(20)
-    negativeVids
-  })
+
 
   def generateNegativeSamples(spark: SparkSession, dt: String, outputPath: String): Unit = {
     val stats = ProcessingStats()
@@ -142,7 +138,11 @@ object video_dssm_sampler {
 
       // 注册UDF
       spark.udf.register("generateNegativeVids", generateNegativeVidsUDF)
-
+      // 3. 定义UDF函数来生成负样本
+      def generateNegativeVidsUDF = udf((vid_left: String, vid_right: String) => {
+        val negativeVids = Random.shuffle(allVids - vid_left - vid_right).take(20)
+        negativeVids
+      })
       // 4. 生成负样本
       val negativeSamplesDF = time({
         val df = positivePairs