Page History

public class Person {
  private String name;
    
  Person() {
    // do nothing - needed for serialization
  }
    
  Person(String theName) {
    name = theName;
  }
    
  public String getName () {
    return name;
  }

  // other details not relevant to this example
}


public class Student extends Person implements Serializable {
  private Professor tutor;
     
  Student() {
    // do nothing - needed for serialization
  }
     
  Student(String theName, Professor theTutor) {
    super(theName);
    tutor = theTutor;
  }
     
  public Professor getTutor() {
    return tutor;
  }
}
 
public class Professor extends Person implements Serializable {  
  private ArrayList<Student>List<Student> tutees = new ArrayList<Student>();
     
  Professor() {
    // do nothing - needed for serialization
  }
     
  Professor(String theName) {
    super(theName);
  }
     
  public ArrayList<Student>List<Student> getTutees () {
    return tutees;
  }
     
  /**
   * checkTutees checks that all the tutees
   * have this Professor as their tutor
   */
  public boolean checkTutees () {
    boolean result = true;
    for (Student stu: tutees) {
      if (stu.getTutor() != this) {
         result = false;
         break;
      }
    }
    return result;
  }
}

// ...
 
Professor jane = new Professor("Jane");
        
Student able = new Student("Able", jane);
Student baker = new Student("Baker", jane);
Student charlie = new Student("Charlie", jane);
        
jane.getTutees().add(able);
jane.getTutees().add(baker);
jane.getTutees().add(charlie);
        
System.out.println("checkTutees returns: " + jane.checkTutees());
// prints "checkTutees returns: true"

String filename = "serial";

 trytry {
	  // Serializing using writeUnshared
  ObjectOutputStream  ObjectOutputStream oos = new ObjectOutputStream
      = new ObjectOutputStream(new FileOutputStream(filename));
            
    oos.writeUnshared(jane);
    oos.close();
            
    // Deserializing using readUnshared
    ObjectInputStream ois = new ObjectInputStream
      = new ObjectInputStream(new FileInputStream(filename));
            
    Professor jane2 = (Professor)ois.readUnshared();
    ois.close();
  System.out.println("checkTutees returns: " +
       
    System.out.println("checkTutees returns: " +
        jane2.checkTutees());
    // prints "checkTutees returns: false"
            
} catch (Exception e) {
    System.out.println("Exception during deserialization" + e);
}

String filename = "serial";

try {
    System.out.println("// Serializing using writeObject");writeUnshared
    ObjectOutputStream oos = new ObjectOutputStream
      = new ObjectOutputStream(new FileOutputStream(filename));
            
    oos.writeObject(jane);
    oos.close();
            
    System.out.println("// Deserializing using readObject");readUnshared
    ObjectInputStream ois = new ObjectInputStream
      = new ObjectInputStream(new FileInputStream(filename));
            
    Professor jane2 = (Professor)ois.readObject();
    ois.close();
  System.out.println("checkTutees returns: "  +
      
    System.out.println("checkTutees returns: " +
        jane2.checkTutees());
    // prints "checkTutees returns: true"
            false"
} catch (Exception e) {
    System.out.println("Exception during deserialization" + e);
}