How to read and write a HashMap to a file?

Question

I have the following HashMap:

HashMap fileObj = new HashMap();

ArrayList cols         


        

Answer 1

I believe you´re making a common mistake. You forgot to close the stream after using it!

 File file = new File("temp");  
 FileOutputStream f = new FileOutputStream(file);  
 ObjectOutputStream s = new ObjectOutputStream(f);          
 s.writeObject(fileObj);
 s.close();