I used a variable with a lot of data in it, say String data. I wanted to use a small part of this string in the following way:
this.smallpart = data.substring(12,18);
After some hours of debugging (with a memory visualizer) I found out that the objects field smallpart remembered all the data from data, although it only contained the substring.
When I changed the code into:
this.smallpart = data.substring(12,18)+"";
..the problem was solved! Now my application uses very little memory now!
How is that possible? Can anyone explain this? I think this.smallpart kept referencing towards data, but why?