列表中的数据框 在Java中

您可以从中创建Dataframe

List<String>

selectExpr

split

public class SparkSample{public static void main(String[] args) {    SparkConf conf = new SparkConf().setAppName("SparkSample").setMaster("local[*]");    JavaSparkContext jsc = new JavaSparkContext(conf);    SQLContext sqc = new SQLContext(jsc);    // sample data    List<String> data = new ArrayList<String>();    data.add("dev, engg, 10000");    data.add("karthik, engg, 20000");    // Dataframe    Dataframe df = sqc.createDataset(data, Enprers.STRING()).toDF();    df.printSchema();    df.show();    // Convert    Dataframe df1 = df.selectExpr("split(value, ',')[0] as name", "split(value, ',')[1] as degree","split(value, ',')[2] as salary");    df1.printSchema();    df1.show();    }}

您将获得以下输出。

root |-- value: string (nullable = true)+--------------------+|    value|+--------------------+|    dev, engg, 10000||karthik, engg, 20000|+--------------------+root |-- name: string (nullable = true) |-- degree: string (nullable = true) |-- salary: string (nullable = true)+-------+------+------+|   name|degree|salary|+-------+------+------+|    dev|  engg| 10000||karthik|  engg| 20000|+-------+------+------+

您提供的样本数据有空格。如果你想删除的空间，有工资类型为“整数”，那么你可以使用

trim

cast

df1 = df1.select(trim(col("name")).as("name"),trim(col("degree")).‌​as("degree"),trim(co‌​l("salary")).cast("i‌​nteger").as("salary"‌​));