Java Programming

Hi! My problem is simple so I feel extremely stupid not being able to find out a solution by myself.
I'm parsing an XML file using SAX, and I need to generate a String from a char[].

If I print in the console the characters one by one, by

for (int i = start; i < start + length; i++) 
{
      System.out.print(ch);

}
I obtain 

[[Categoria:Statunitensi]]
[[Categoria:Sport negli Stati Uniti]]
[[Categoria:Sportivi per nazionalit�|Statunitensi]]

but if I try to get the string I need, by
String tmp = new String();

for (int i = start; i < start + length; i++) 

{

tmp += ch[i];

}
and then I try to print it, I obtain

[[Categoria:Statunitensi]]
[[Categoria:Sport negl
i Stati Uniti]]
[[Categoria:Sportivi per nazionalit�|Statunitensi]]

I know that a StringReader is better, but it gives the same problem.  Tried with the String(char[]) constructor but the same. 

A virtual beer to anyone able to solve this... thank you!!!!

Francesco