Properties.store(OutputStream) destroys order and comments of *.properties

Question

Hi!
After searching for hours in different forums I have come to the point, that either
1)I'm not good in searching forums
2)This problem has not been discussed yet
no 1 seems much more likely...
So, here it it is:
I'm trying to implement a kind of property-loader which loads keys from a text file (in my case called *.properties file) into the java.util.properties class, manipulates it, and then stores it again.
Apart from my manipulation, I want the *.properties file to stay exactly the same.
As I have it now store(FileOutputStream) seems to changes many things in the file: It adds the date, deletes the comments, changes the order of the keys
Here is the test code:
public class IoTestMain {
     public static void main(String[] args)
         Properties properties = new Properties();
         try {
             properties.load(new FileInputStream("C:\\eclipse\\workspace\\IoTest\\iotest\\filename.properties"));
             properties.setProperty("Test1","1");            
         } catch (IOException e) {
              e.printStackTrace();
         try {
             properties.store(new FileOutputStream("C:\\eclipse\\workspace\\IoTest\\iotest\\filename.properties"),null);
         } catch (IOException e) {
              e.printStackTrace();
}This changes my "beautiful" filename.properties file from
[filestart]
Test2=1
#comment
!comment
Test1=2
[fileend]
to that:
[filestart]
#Wed Sep 14 12:23:10 CEST 2005
Test1=1
Test2=1
[fileend]
I'd like to have a properties file with comments and defined order. Does someone have suggestions?
Regards
Phil

Answer 1

Properties is not meant to keep the order of it's entries or comments. It's a very simple tools for very simple requirements. It provides only the very simple function of mapping keys to strings, no fancy "keep the format when storing" and no "remember the comments to write it back".
Ceci hinted at java.util.prefs.Preferences as the prefered way to store user preferences ('though I've never used it, so I can't comment on it).