How to serialize a lambda?
java, java-8, lambda, serialization
Solution
Java 8 introduces the possibility to cast an object to an intersection of types by adding multiple bounds. In the case of serialization, it is therefore possible to write:
Runnable r = (Runnable & Serializable)() -> System.out.println("Serializable!");
And the lambda automagically becomes serializable.
Problem
How can I elegantly serialize a lambda? For example, the code below throws a `NotSerializableException`. How can I fix it without creating a `SerializableRunnable` "dummy" interface? ``` public static void main(String[] args) throws Exception { File file = Files.createTempFile("lambda", "ser").toFile(); try (ObjectOutput oo = new ObjectOutputStream(new FileOutputStream(file))) { Runnable r = () -> System.out.println("Can I be serialized?"); oo.writeObject(r); } try (ObjectInput oi = new ObjectInputStream(new FileInputStream(file))) { Runnable r = (Runnable) oi.readObject(); r.run(); } } ```