Play 2.2 Scala class serializable for cache - scala

Question

I have one scala class from play-mongojack example. It works fine. However, when I tried to save it in Play ehcache, it throws NotSerializableException. How can I make this class serializable?
class BlogPost(#ObjectId #Id val id: String,
#BeanProperty #JsonProperty("date") val date: Date,
#BeanProperty #JsonProperty("title") val title: String,
#BeanProperty #JsonProperty("author") val author: String,
#BeanProperty #JsonProperty("content") val content: String) {
#ObjectId #Id #BeanProperty var blogId: String = _
#BeanProperty #JsonProperty("uploadedFile") var uploadedFile: Option[(String, String, Long)] = None
}
object BlogPost {
def apply(
date: Date,
title: String,
author: String,
content: String): BlogPost = new BlogPost(date,title,author,content)
def unapply(e: Event) =
new Some((e.messageId,
e.date,
e.title,
e.author,
e.content,
e.blogId,
e.uploadedFile) )
private lazy val db = MongoDB.collection("blogposts", classOf[BlogPost], classOf[String])
def save(blogPost: BlogPost) { db.save(blogPost) }
def findByAuthor(author: String) = db.find().is("author", author).asScala
}
Saving to cache:
var latestBlogs = List[BlogPost]()
Cache.set("latestBlogs", latestBlogs, 30)
It throws an exception:
[error] n.s.e.s.d.DiskStorageFactory - Disk Write of latestBlogs failed:
java.io.NotSerializableException: BlogPost
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1183) ~[na:1.7.0_45]
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347) ~[na:1.7.0_45]
at java.util.ArrayList.writeObject(ArrayList.java:742) ~[na:1.7.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.7.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[na:1.7.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.7.0_45]
EDIT 1:
I tried to extends the object with Serializable, it doesn't work.
object BlogPost extends Serializable {}
EDIT 2:
The vitalii's comment works for me.
class BlogPost() extends scala.Serializable {}

Answer 1

Try to derive class BlogPost from Serializable or define it as a case class which are serializable by default.