//: io/MyWorld.java import java.io.*; import java.util.*; import static net.mindview.util.Print.*; class House implements Serializable {} class Animal implements Serializable { private String name; private House preferredHouse; Animal(String nm, House h) { name = nm; preferredHouse = h; } @Override public String toString() { return name + "[" + super.toString() + "], " + preferredHouse + "\n"; } } public class MyWorld { public static void main(String[] args) throws IOException, ClassNotFoundException { House house = new House(); List animals = new ArrayList<>(); animals.add(new Animal("Bosco the dog", house)); animals.add(new Animal("Ralph the hamster", house)); animals.add(new Animal("Molly the cat", house)); print("animals: " + animals); ByteArrayOutputStream buf1 = new ByteArrayOutputStream(); ObjectOutputStream o1 = new ObjectOutputStream(buf1); o1.writeObject(animals); o1.writeObject(animals); // Write a 2nd set // Write to a different stream: ByteArrayOutputStream buf2 = new ByteArrayOutputStream(); ObjectOutputStream o2 = new ObjectOutputStream(buf2); o2.writeObject(animals); // Now get them back: ObjectInputStream in1 = new ObjectInputStream( new ByteArrayInputStream(buf1.toByteArray())); ObjectInputStream in2 = new ObjectInputStream( new ByteArrayInputStream(buf2.toByteArray())); List animals1 = (List)in1.readObject(), animals2 = (List)in1.readObject(), animals3 = (List)in2.readObject(); print("animals1: " + animals1); print("animals2: " + animals2); print("animals3: " + animals3); } } /* Output: (Sample) animals: [Bosco the dog[Animal@addbf1], House@42e816 , Ralph the hamster[Animal@9304b1], House@42e816 , Molly the cat[Animal@190d11], House@42e816 ] animals1: [Bosco the dog[Animal@de6f34], House@156ee8e , Ralph the hamster[Animal@47b480], House@156ee8e , Molly the cat[Animal@19b49e6], House@156ee8e ] animals2: [Bosco the dog[Animal@de6f34], House@156ee8e , Ralph the hamster[Animal@47b480], House@156ee8e , Molly the cat[Animal@19b49e6], House@156ee8e ] animals3: [Bosco the dog[Animal@10d448], House@e0e1c6 , Ralph the hamster[Animal@6ca1c], House@e0e1c6 , Molly the cat[Animal@1bf216a], House@e0e1c6 ] *///:~