Tuesday 9 August 2011

Edit Jar Application! ie OPERA MINI


1.) HxD Hex Editor(PC) or MobileHex/ZNXTHAN ( Mobile)

2.) WinRar (PC) Or Jarboom (Mobile)

I'm posting on how to modify a java
application particularly a Opera Mini 4.2 version on pc . You will need a
HexEditor and a Opera Mini 4.2 version (.jar) file. Install the
HexEditor application on your PC. So Now we can start modifying a OM4.2.
jar. For the HexEditor Application. Just Search On Google to download
hexeditor. Open your OM4.2. jar with WinRar (I know everyone knows this
WinRar application). This part you will learn how to edit your proxy url
of OM4.2 

1. For the proxy url of the OM4.2 to be edit drag the a.class file on any folder. 

2. Start your HexEditor application and open the a. class on it. 

Press Ctr+R (to search and replace) “ server4. ” and
replace your desired proxy url. In this tutorial I ’m gonna use the MTN
url ( working as of the day I posted this thread). “ http:// @ :80 /” 

4. Click "OK" (not replace all) because there are 2( two) “server4…” can be found in this file. 

5 . It will turned into red text your edited line. 

6. Highlight the red text and take note the “ Length” that can be found at the bottom of HexEditor window. 

7. In this tutorial. I had a 43 in length. 

8. Highlight the character before the red text and select “Edit” on menu and select “Fill selection…” 

9. Click "OK". 

Save the file and drag back the a.class to winrar window. Disregard the
a.class.bak 11. Now your done with the proxy url of your OM4.2 . 


1. Drag the f.class on any folder from your WinRar window. 

2. Open HexEditor application and open the f.class on it. 

Press Ctr+R (to search and replace) “ v. 4.2.13337, 20081205 ” and
replace your desired name. NOTE: There's a space before “v. 4.2.13337,
20081205” THEREFORE: It should also have a space before your desired
name. In this tutorial I'm gonna use the " modified for 9

4. Click "OK" 

5. Take note the Length of your edited line. In this tutorial, I had "1 B" in Length 

6. On menu tab Go To - Edit - Fill Selection… 

Enter the Length "1 B" REMINDER: If your desired name has a single
character just add 0( zero) before it. For Example: You found 4 in your
Length, your Fill Selection is "04 ". If you found C in your Length, you
Fill Selection is "0 C". Get it? 

Save your project and drag back the f.class to WinRar window. Disregard
the f.class.bak There are so many ways modifying a jar application but
this could be the simplest way to modify for the beginners. The file
that has the extension name ". bak" are the back-up files of your edited
class file. If you think that you are not sure with your edition just
rename and delete the ".bak" file and it will bring back the original

Do you want to personalize your opera with your splashes and name? Then here's a tutorial for you!!! REQUIREMENTS 

1.) HxD Hex Editor(PC) or MobileHex/ZNXTHAN ( Mobile) 

2.) WinRar(PC) Or Jarboom (Mobile) 3.) Image Ready or any image editor (PC) OR Image Designer (Mobile)  


I am giving example of editing splash of Opera Mini 4. 2 !!! So here we go:

1.) Extract all the files of the java app you want to edit(Here Opera mini 4.2)

2.) Open HxD Hex Editor and open v file from the extracted files.

3.) Next go to search option or Ctrl + F and search for PNG.

4.) There are only two png in the v file.

5.) Go to the second one. It will be something like (
ePNG........IHDR...b.........6 A? ...`PLTE#..,.'OW \uooyyyE,4- O|

6.) Open the splash you have created i.e png file you have created
(Splash creation tutorial below) in HxD Hex Editor in another tab.

7.) Press Ctrl+A and Ctrl+C to copy all the Hex of the png file.

8.) Next Go to the tab of V file and select text from ePNG to IENDRB`,

9.) Now press Ctrl +B to paste write. So all the text will become red in color.

10.) Now if the file size of the splash you created is smaller than 770
bytes, then you can find a second IENDRB`, AS IN above screenshot.

11.) So now select the remaining text(which is not red) upto IENDRB`, AS IN above screenshot.

12.) Now go to edit and fill selection option and fill HEX values = 00

13.) Now save the file.

14.) Update the modded file with winrar or jarboom.

15.) Your Splash is Ready. See the output by installing in your phone or Kemulator or other emulator  


suggest you to prepare your splash in ImageDesigner. It is a good
python image editor and creator. And by using the image compression
feature decrease the size to 770 bytes or lower. NOTE: Keep the

1.) File size 770 bytes or below

2.) Format as PNG 3.) Dimensions as you wish (98 X 42 - My dimensions)


1.) Open the file in HxD Hex Editor, and search for OPERA MINI

2.) But here you can change this only by 10 letters as OPERA MINI=10 words.

3.) You can also change other places and warnings or notes by searching
for it like LOADING NOTE: But Keep in Mind that keep the no. of
characters same i.e Loading=7. So keep no. of characters 7. Increasing
no. of characters or inserting bytes will change file size and result in
crashing of the program.