如何在Java中添加两个不同列的Spark数据帧

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;

public class AddColumnsToDataFrame {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("AddColumnsToDataFrame")
                .master("local")
                .getOrCreate();

        // 创建df1数据帧
        Dataset<Row> df1 = spark.createDataFrame(
                List.of(
                        new CustomRow("A", 1),
                        new CustomRow("B", 2),
                        new CustomRow("C", 3)
                ),
                CustomRow.class
        );

        // 创建df2数据帧
        Dataset<Row> df2 = spark.createDataFrame(
                List.of(
                        new CustomRow("X", 4),
                        new CustomRow("Y", 5),
                        new CustomRow("Z", 6)
                ),
                CustomRow.class
        );

        // 添加两个不同列的数据帧
        Dataset<Row> mergedDF = df1.withColumn("col3", df2.col("col1")).withColumn("col4", df2.col("col2"));

        // 显示合并后的数据帧
        mergedDF.show();
    }

    // 自定义数据行类
    public static class CustomRow {
        private String col1;
        private int col2;

        public CustomRow(String col1, int col2) {
            this.col1 = col1;
            this.col2 = col2;
        }

        // 省略getter和setter方法
    }
}