OnJava8-Examples/serialization/MyWorld.java

// serialization/MyWorld.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
import java.io.*;
import java.util.*;

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<Animal> 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));
    System.out.println("animals: " + animals);
    try(ByteArrayOutputStream buf1 =
          new ByteArrayOutputStream();
        ObjectOutputStream o1 =
          new ObjectOutputStream(buf1)) {
      o1.writeObject(animals);
      o1.writeObject(animals); // Write a 2nd set
      // Write to a different stream:
      try(ByteArrayOutputStream buf2 =
            new ByteArrayOutputStream();
          ObjectOutputStream o2 =
            new ObjectOutputStream(buf2)) {
        o2.writeObject(animals);
        // Now get them back:
        try(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();
          System.out.println("animals1: " + animals1);
          System.out.println("animals2: " + animals2);
          System.out.println("animals3: " + animals3);
        }
      }
    }
  }
}
/* Output:
animals: [Bosco the dog[Animal@1db9742], House@106d69c
, Ralph the hamster[Animal@52e922], House@106d69c
, Molly the cat[Animal@25154f], House@106d69c
]
animals1: [Bosco the dog[Animal@1a4f24f], House@19a45b3
, Ralph the hamster[Animal@99a589], House@19a45b3
, Molly the cat[Animal@372a00], House@19a45b3
]
animals2: [Bosco the dog[Animal@1a4f24f], House@19a45b3
, Ralph the hamster[Animal@99a589], House@19a45b3
, Molly the cat[Animal@372a00], House@19a45b3
]
animals3: [Bosco the dog[Animal@dd8dc3], House@103e736
, Ralph the hamster[Animal@8db2f2], House@103e736
, Molly the cat[Animal@18bf509], House@103e736
]
*/