我正在尝试一个scala和java组合项目,我有一个scala类,其缩写结构如下
case class Dl(name:String, length:Int) extends Serializable
class DlStruct private(xs:List[Dl]) extends Serializable {
def this()= this(Nil)
private def +=(dl:DataLayout): RowSchema =
new RowSchema(xs :+ dl)
def appendDl(fieldName:String, fieldLength:Int):DlStruct=
this += Dl(fieldName,fieldLength)
}
从Java对象调用上述类以填充DlStruct,完成后,我将类文件写为序列化文件。
当我再次反序列化文件并将其转换回对象时,使用IntelliJ进行工作时,它工作得很好,但是如果我尝试从spark-submit中运行相同的代码,则会引发以下错误:-
java.lang.ClassCastException: cannot assign instance of scala.collection.immutable.List$SerializationProxy to field somepackage.DlStruct.xs of type scala.collection.immutable.List in instance of somepackage.DlStruct.xs
at java.base/java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2205)
at java.base/java.io.ObjectStreamClass$FieldReflector.checkObjectFieldValueTypes(ObjectStreamClass.java:2168)
at java.base/java.io.ObjectStreamClass.checkObjFieldValueTypes(ObjectStreamClass.java:1422)
at java.base/java.io.ObjectInputStream.defaultCheckFieldValues(ObjectInputStream.java:2450)
at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2357)
at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2166)
at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1668)
at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2434)
at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2328)
at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2166)
at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1668)
at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:482)
at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:440)
常见的Java对象的反序列化也没有问题
反序列化的代码段
File file = new File(serializedFilePath);
FileInputStream fin = new FileInputStream(file);
ObjectInputStream in = new ObjectInputStream(fin);
infoHolder = (ObjectCarrier) in.readObject(); // <- this line gives error if it has scala object, else runs smoothly
in.close();
fileIn.close();
Spark版本-2.4.4 Scala版本-2.12.8 Java- 1.8
答案 0 :(得分:0)
我不得不将scala类转换为Java,以使其最终开始在spark-submit中工作,我希望有人为此找到更好的答案。