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Notserializable exception when trying to serialize a java map converted from scala

I have a way to serialize a java map Map<UUID,String> . It is working fine. I can serialize and deserialize in java.

But I have to call this method from scala, and this is my call code.

 def customSerialize:Unit = { Serializer.serialize(modMap(scalaMap)) def modMap(oldMap : Map[UUID,SomeObject]) : java.util.Map[UUID,java.lang.String] = { oldMap map { case(k,v) => (k->v.name)} }

The scala map is scala.collection.Map , and I use import scala.collection.JavaConversions._ to do the conversion.

When I run this code, I get an error

 java.io.NotSerializableException: scala.collection.JavaConversions$MapWrapper at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)

It looks like I need another conversion from javaconversions$MapWrapper to java.util.Map . It's right? Is there any way to do this?

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2 answers

Personally, I would open the improvement problem by requiring these wrappers to be serialized. Not that it helps you in the short term, but ...

Have you tried stuff in JavaConverters instead?

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As far as I can tell, you need to copy the map because MapWrapper is not serializable. It would be best for Scala to support this, but at the same time, a reasonable syntax is to simply use the copy constructor for the java map. Your call will look like this:

 Serializer.serialize(new java.util.HashMap(modMap(scalaMap)))
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Source: https://habr.com/ru/post/972489/

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