根据条件在spark数据集中添加列值

public class EmployeeBean implements Serializable {

private Long id;

private String name;

private Long salary;

private Integer age;

// getters and setters

}
相关的saprk代码：

SparkSession spark = SparkSession.builder().master("local[2]").appName("play-with-spark").getOrCreate();
List employees1 = populateEmployees(1, 10);

Dataset ds1 = spark.createDataset(employees1, Encoders.bean(EmployeeBean.class));
ds1.show();
ds1.printSchema();

Dataset ds2 = ds1.where("age is null").withColumn("is_age_null", lit(true));
Dataset ds3 = ds1.where("age is not null").withColumn("is_age_null", lit(false));

Dataset ds4 = ds2.union(ds3);
ds4.show();
相关产出：

DS1

DS4

有没有更好的解决方案在数据集中添加此列而不是创建两个数据集并执行联合？