我有一个json文件，我正在spark中读取。
但是，当我试图读取info列或任何子元素时，架构总是显示为null(（不为空）

//reading file
val df = spark.read.json("FilePath")

df.printSchema()

    root
     |-- data_is: boolean (nullable = true)
     |-- Student: struct (nullable = true)
     |    |-- Id: string (nullable = true)
     |    |-- JoinDate: string (nullable = true)
     |    |-- LeaveDate: string (nullable = true)
     |-- Info: struct (nullable = true)
     |    |-- details: array (nullable = true)
     |    |    |-- element: struct (containsNull = true)
     |    |    |    |-- Father_salary: double (nullable = true)
     |    |    |    |-- Mother_salary: double (nullable = true)
     |    |    |    |-- Address: String (nullable = true)
     |    |-- studentInfo: struct (nullable = true)
     |    |    |-- Age: double (nullable = true)
     |    |    |-- Name: String (nullable = true)

df.select("Student").show()

显示student元素中的字段值，即使在解析时也是如此 Student.Id 我能拿到身份证
但是每当解析信息时，我总是得到一个在文件中不为null的null值。

df.select("Info").show() // is showing as NULL
df.select("Info.detail").show() // is showing as NULL

甚至 Info.Summary 为空。
有人能建议如何得到实际的字段值而不是空值吗？
json文件

{"Student":{"JoinDate":"20200909","LeaveDate":"20200909","id":"XA12"},"Info":{"studentInfo":{"Age":13,"Name":"Alex"},"details":[{"Father_salary":1234.00,"Mother_salary":0,"Address":""}]},"data_is":true}