java - Object won't read in properly -

i'm writing program writes array object java binary file read in. problem when array read in returning [null, null]. not reading/writing object correctly?

dbms.java

public static void writetofile(datab[] friends) {     try {         objectoutputstream mystream = new objectoutputstream(                 new fileoutputstream("datt.dat"));         for(int i=0; i<friends.length; i++){         mystream.writeobject(friends[i]);         }         mystream.close();     }      catch (filenotfoundexception e) {     } catch (ioexception e) {     }      system.out.println("\n\narray written file datt."); }  /**********************************************************  * readfromfile read binary file , return array of objects  * calling method catch following exceptions: filenotfoundexception,  * classnotfoundexception, , ioexception (know each does!)  *   * @return array read in binary input file  */ public static datab[] readfromfile() {     system.out             .println("\n\nnow let's reopen file , display array.");     datab[] b = null;      // name of file open.     string filename = "datt.dat";      try {         // use reading data.         byte[] buffer = new byte[1000];          objectinputstream input = new objectinputstream(new fileinputstream("datt.dat"));          input.close();      } catch (filenotfoundexception ex) {         system.out.println("unable open file '" + filename + "'");     } catch (ioexception ex) {         system.out.println("error reading file '" + filename + "'");         // or this:         // ex.printstacktrace();     }     return b;  } 

output: array before writing output file:

[robert , duchar 7345555555, len , gt 7345555567] 

array written file datt.

now let's reopen file , display array.

the array read in input file... see array backwards or forwards? enter answer (b or f): f

[null, null] 

you declaring b null value initialization.

datab[] b = null; 

then updating value of b

then returning b initialzed null