大数据环境下Java框架的开发效率

import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.types.DataTypes;
import org.apache.spark.sql.functions;

public class SparkSQLSalesAnalysis {

    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder().appName("Sales Analysis").getOrCreate();

        // 使用DataFrames API读取数据
        DataFrame sales = spark.read().csv("sales.csv");

        // 将CSV列转换为适当的数据类型
        sales = sales.withColumn("product_id", sales.col("product_id").cast(DataTypes.IntegerType));
        sales = sales.withColumn("quantity", sales.col("quantity").cast(DataTypes.IntegerType));
        sales = sales.withColumn("price", sales.col("price").cast(DataTypes.DecimalType(10, 2)));

        // 使用SQL计算总销售额
        DataFrame totalSales = sales.groupBy("product_id").agg(functions.sum("quantity").alias("total_quantity"),
                functions.sum("price").alias("total_sales"));

        // 显示结果
        totalSales.show();
    }
}