How to count number of objects stored in a *.ser file

I'm trying to read all the objects stored in a *.ser file and store them in a array of objects. How can I get the number of objects stored in that file(So that I can declare the array to be number_of_objects long)?

I've checked the API and was unable to find a Desirable function.

-edit-

A Part of the code:

Ser[] objTest2 = new Ser[number开发者_C百科_of_objects];
for(int i=0; i<=number_of_objects, i++) {
    objTest2[i] = (Ser)testOS2.readObject();
    objTest2[i].printIt(); 
}

What you want to look at is the ArrayList class.

It is basically a dynamically growing Array.

You can add items to it like so:

ArrayList list = new ArrayList();
list.add(someObject);
list.add(anotherBoject);

The list will grow as you add new items to it. So you don't have to know the size ahead of time.

If you need to get an array out if the List at the end you can use the toArray() method of List.

Object[] arr = list.toArray(new Object[list.size()]);

Edit:
Here is a general implementation of what you need:

List<Ser> objTest2 = new ArrayList<Ser>();
while (testOS2.available > 0) {
    Ser toAdd = ((Ser)testOS2.readObject());
    toAdd.printIt(); 
    objTest2.add(toAdd);
}

*I don't think available() is a reliable test for whether or not there are more bytes to read.

Year's later this post is still relevant. I was looking for a way to loop through a .ser file while de-serializing each file, and to some extent, Rohit Singh's post helped. This is my version of the same though:

ArrayList<Profile> availableProfiles = new ArrayList<Profile>();
    try {
        FileInputStream fileStream = new FileInputStream("profiles.ser");
        ObjectInputStream os = new ObjectInputStream(fileStream);

        Object profileObject = null;
        while((profileObject = os.readObject()) != null) {
            Profile castObject = (Profile) profileObject;
            availableProfiles.add(castObject);
        }
        os.close();
    }  catch(Exception ex) {
        if(ex instanceof EOFException) {
            out.println("End of file reached!");
            out.println("Total profiles found is: " + availableProfiles.size());
        } else if(ex instanceof FileNotFoundException) {
            out.println("File not found! \n Answer the following to create your profile");
            createProfile();
        }
    }

The most important part is the position of the while-loop. In my version, that loop does not create a new FileInputStream or ObjectInputStream like Singh's does. That will make the ObjectInputStream read the .ser file afresh each time those two are created, and as a result, you only add() one Profile object to the ArrayList- the first one to be serialized- each time the loop restarts. Instead, we only loop the with the readObject() method until it produces a null signifying no other object was found in the file, and it triggers the EOFException.

  while(true)
 {

      try
      {
      Employee e=(Employee) ois.readObject();
      System.out.println("successfully deserialized.........showing details of object.");
      e.display();
      }

      catch(Exception e)
      {
          if(e instanceof java.io.EOFException)
          {
          System.out.println("All objects read and displayed");
          break;
          }
          else
          {
              System.out.println("Some Exception Occured.");
              e.printStackTrace();

          }
        }
 }

Just keep reading objects until you get EOFException. That's what it's for. And use a List instead of an array so you don't need the count in advance.