Thread: Error concerning Object Serialization for i/o

The next code concerning Object Serialization produces, when using Netbeans, the following error (no error marking in the code itself). What is this error about?

Exception in thread "main" java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file networking/Employee
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader. java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java :615)
at java.security.SecureClassLoader.defineClass(Secure ClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader .java:283)
at java.net.URLClassLoader.access$000(URLClassLoader. java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java: 197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 47)
at networking.ObjectRefTest.main(ObjectRefTest.java:2 5)
Java Result: 1
BUILD SUCCESSFUL (total time: 3 seconds)

Here is the complete code:

package networking;
 
/**
 *
 * 
 */
/**
   @version 1.10 17 Aug 1998
   @author Cay Horstmann
*/
 
 
import java.io.*;
import java.util.*;
 
class ObjectRefTest
{
   public static void main(String[] args)
   {
      Employee harry = new Employee("Harry Hacker", 50000, 1989, 10, 1);
      Manager boss = new Manager("Carl Cracker", 80000, 1987, 12, 15);
      boss.setSecretary(harry);
 
      Employee[] staff = new Employee[3];
 
      staff[0] = boss;
      staff[1] = harry;
      staff[2] = new Employee("Tony Tester", 40000, 1990, 3, 15);
 
      try
      {
         // save all employee records to the file employee.dat
         ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("employee.dat"));
         out.writeObject(staff);
         out.close();
 
         // retrieve all records into a new array
         ObjectInputStream in =  new ObjectInputStream(new FileInputStream("employee.dat"));
         Employee[] newStaff = (Employee[]) in.readObject();
         in.close();
 
         // raise secretary's salary
         newStaff[1].raiseSalary(10);
 
         // print the newly read employee records
         for (Employee e : newStaff)
            System.out.println(e);
      }
      catch (Exception e)
      {
         e.printStackTrace();
      }
   }
}
 
class Employee implements Serializable
{
   public Employee() {}
 
   public Employee(String n, double s, int year, int month, int day)
   {
      name = n;
      salary = s;
      GregorianCalendar calendar = new GregorianCalendar(year, month - 1, day);
      hireDay = calendar.getTime();
   }
 
   public String getName()
   {
      return name;
   }
 
   public double getSalary()
   {
      return salary;
   }
 
   public Date getHireDay()
   {
      return hireDay;
   }
 
   public void raiseSalary(double byPercent)
   {
      double raise = salary * byPercent / 100;
      salary += raise;
   }
 
   public String toString()
   {
      return getClass().getName()
         + "[name=" + name
         + ",salary=" + salary
         + ",hireDay=" + hireDay
         + "]";
   }
 
   private String name;
   private double salary;
   private Date hireDay;
}
 
class Manager extends Employee
{
   /**
      Constructs a Manager without a secretary
      @param n the employee's name
      @param s the salary
      @param year the hire year
      @param month the hire month
      @param day the hire day
   */
   public Manager(String n, double s, int year, int month, int day)
   {
      super(n, s, year, month, day);
      secretary = null;
   }
 
   /**
      Assigns a secretary to the manager.
      @param s the secretary
   */
   public void setSecretary(Employee s)
   {
      secretary = s;
   }
 
   public String toString()
   {
      return super.toString()
        + "[secretary=" + secretary
        + "]";
   }
 
   private Employee secretary;
}

--- Update ---

I might have a problem with Netbeans 6.9
Now, of a program that worked fine, I get this cryptic message:


run:
Exception in thread "main" java.lang.NoSuchMethodError: networking.Manager.setBonus(D)V
at networking.ObjectFileTest.main(ObjectFileTest.java :21)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

What is the name of the source file? Is it Employee.java? It should be ObjectRefTest.java.

Never mind. Didn't see the update. I have no idea.

the class name is:
class ObjectFileTest
{
public static void main(String[] args)

The name of the file is: ObjectFileTest.java

The above code is working and now I have an error with this one:

package networking;
 
/**
   @version 1.11 2004-05-11
   @author Cay Horstmann
*/
 
import java.io.*;
import java.util.*;
 
class ObjectFileTest
{
   public static void main(String[] args)
   {
      Manager boss = new Manager("Carl Cracker", 80000, 1987, 12, 15);
      boss.setBonus(5000);
 
      Employee[] staff = new Employee[3];
 
      staff[0] = boss;
      staff[1] = new Employee("Harry Hacker", 50000, 1989, 10, 1);
      staff[2] = new Employee("Tony Tester", 40000, 1990, 3, 15);
 
      try
      {
         // save all employee records to the file employee.dat
         ObjectOutputStream out = new ObjectOutputStream(new
							FileOutputStream("employee.dat"));
         out.writeObject(staff);
         out.close();
 
         // retrieve all records into a new array
         ObjectInputStream in =  new ObjectInputStream(new
						FileInputStream("employee.dat"));
         Employee[] newStaff = (Employee[]) in.readObject();
         in.close();
 
	    // give an 10% raise to new object
 	    for (int i = 0; i < newStaff.length ; i++) {
            newStaff[i].raiseSalary(10);
         }
 
         // print the newly read employee records
         for (Employee e : newStaff)
            System.out.println(e);
      }
      catch (Exception e)
      {
         e.printStackTrace();
      }
   }
}
 
class Employee implements Serializable
{
   public Employee() {}
 
   public Employee(String n, double s, int year, int month, int day)
   {
      name = n;
      salary = s;
      GregorianCalendar calendar =
				new GregorianCalendar(year, month - 1, day);
      hireDay = calendar.getTime();
   }
 
   public String getName()
   {
      return name;
   }
 
   public double getSalary()
   {
      return salary;
   }
 
   public Date getHireDay()
   {
      return hireDay;
   }
 
   public void raiseSalary(double byPercent)
   {
      double raise = salary * byPercent / 100;
      salary += raise;
   }
 
   public String toString()
   {
      return getClass().getName()
         + "[name=" + name
         + ",salary=" + salary
         + ",hireDay=" + hireDay
         + "]";
   }
 
   private String name;
   private double salary;
   private Date hireDay;
}
 
 
class Manager extends Employee
{
   /**
      @param n the employee's name
      @param s the salary
      @param year the hire year
      @param month the hire month
      @param day the hire day
   */
   public Manager(String n, double s, int year, int month, int day)
   {
      super(n, s, year, month, day);
      bonus = 0;
   }
 
   public double getSalary()
   {
      double baseSalary = super.getSalary();
      return baseSalary + bonus;
   }
 
   public void setBonus(double b)
   {
      bonus = b;
   }
 
   public String toString()
   {
      return super.toString()
        + "[bonus=" + bonus
        + "]";
   }
 
   private double bonus;
}

--- Update ---

To be clear, when running the above code I get this error (no error mark in the code itself):

Exception in thread "main" java.lang.NoSuchMethodError: networking.Manager.setBonus(D)V
at networking.ObjectFileTest.main(ObjectFileTest.java :21)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

Hello.
I executed your code on Netbeans 7.3 IDE.
It executed without any exceptions.

Syed.

weird, because the code is from the middle ages! I might have to go to 7.3
I update or do I have to do a new installation?
Doas 7.3 run on Mac 10.6.8?