how can i count objects in an object file

[rishman toor]

I stored so many objects in a file using file output stream.but when read these objects using file input stream just find last one.how can i read all objects in an file?And how can i find that how many objects a file contained?And another question is how can i make a java exe file?
Thankz in advance.

[Jeff Albertson]

Post a minimal expample program demonstrating your problem.

[rishman toor]

hi
how can i read all objects from the beginning of a file?How can i get the number of objects in a stored file?

[Jeff Albertson]

> how can i read all objects from the beginning of a file?

By repeatedly calling readObject

> How can i get the number of objects in a stored file?

By counting the number of times you called readObject.

Have you considered writing one thing to the file, a java.util.List of all your objects?

[Layne Lund]

I'm not too familiar with the Serialization mechanism in Java, but I suspect that each object is the same size. If you can find out this size and the size of the file, you can easily calculate the number of objects by

numberOfObjects = sizeOfFile / sizeOfObject;

As for reading every object from the file, you can use a while loop and call readObject() repeatedly, as Jeff suggested. If you just want to read the last object (or any object at a given position), you may want to look at the RandomAccessFile class.

I hope this gives you some suggestions as to what to try. If not, please come back with a description of the problem you are trying to solve. You may also want to post some code to illustrate what you have tried to solve it on your own.

Layne

[Matt Gatten]

You could also just make sure your code creates an object with a null value or something last and just keep looping through the read objects while xValue does not equal 'null'.