jc = sc._jvm.java.lang.Thread.currentThread().getContextClassLoader(
    ).loadClass(pcls).newInstance().getUdf().apply
return Column(jc(_to_seq(sc, [], _to_java_column)))
rdd1 = sc.parallelize([{'c1': 'a'}, {'c1': 'b'}, {'c1': 'c'}])
df1 = rdd1.toDF()
df2 = df1.withColumn('mycol', my_udf())
Implement a java UDF and call it from pyspark