convert RDD to Dataset in Java Spark

.createDataset() accepts RDD<T> not JavaRDD<T>. JavaRDD is a wrapper around RDD inorder to make calls from java code easier. It contains RDD internally and can be accessed using .rdd(). The following can create a Dataset:

Dataset<Person> personDS =  sqlContext.createDataset(personRDD.rdd(), Encoders.bean(Person.class));