Encoder for Row Type Spark Datasets

Question

I would like to write an encoder for a Row type in DataSet, for a map operation that I am doing. Essentially, I do not understand how to write encoders.

Below is an exam

Answer 1

The answer is to use a RowEncoder and the schema of the dataset using StructType.

Below is a working example of a flatmap operation with Datasets:

    StructType structType = new StructType();
    structType = structType.add("id1", DataTypes.LongType, false);
    structType = structType.add("id2", DataTypes.LongType, false);

    ExpressionEncoder encoder = RowEncoder.apply(structType);

    Dataset output = join.flatMap(new FlatMapFunction() {
        @Override
        public Iterator call(Row row) throws Exception {
            // a static map operation to demonstrate
            List