Technical Support


Jar2Exe can run in Wizard mode and Command line mode.

Get detailed usage of Wizard mode, command line mode and generated binary files.


Parameters can be configured to generated binary executive, such as Java VM parameters, system properties etc.

This is the descriptions of configurations, including overview introductions and detailed syntax.

Integrate API

To integrate with generated exe is not necessary. But if you want to let some of the enhanced functions to work, you need to do a little of integration. Every api to integrate is very simple.

This is the introduction and usages of API.


You can learn to use Jar2Exe by referring to the demo programs.

Solution advices

Typical usage of Jar2Exe with detailed steps and live demos in practice.

Such as console tool, desktop window, background service, webapp etc.




After purchased, you need to activate Jar2Exe before you use Jar2Exe to generate exe files for redistributing. Activated Jar2Exe will authorize generated exe to run as a product.

This is to tell you how to activate.


Typical questions asked by Jar2Exe users.



2 Issues with Jar2Exe on our project

I purchased Jar2exe today to package my Jar file into a executable. I am currently experiencing two issues:

1) When I run the exe the ‘look and feel’ of the Java application have been removed. It reverts from the back look and feel to a grey default look - yet if I run the JAR it works correctly

2) The exe loads the application. Then when I close the application it reopens. It only reopens once. Once again, testing the input JAR this does not occur

I would be grateful for any help with this urgently from admin or anyone who can help :-) , Thanks

It's a problem of Jar2Exe in a very detail

Thank you for your message.

This is caused by a new problem of Jar2Exe since V2.1.6 and I have fixed it. I'm so sorry for the inconvenience.

it can be cracked

I downloaded the free version,and publish a beta version,I use hide and encryp function,but it can be cracked,some people already publish they cracked result。。。so said

Please refer to

I'm so sorry to hear that your encrypted program is hacked. For professional hackers, we are difficult to get it 100% safe, even for Windows or iOS, so what we can do is to let is more and more difficult to hack.

Jar2Exe does 2 things to protect java program (1) confusing the filename within jar file, (2) encrypt jar file.

Besides the protection of Jar2Exe, there are some other advices on doing more steps to protect java program: , that is to do an (3) abfuscation and (4) exe file encryption.


I tested out your software to wrap and protect my java application. I really liked it and the application runs perfect. Except or one thing: the application is a JavaFX application, so when i run it, it does not load the css files. Even when u uncheck the protection option.

Any suggestions?

Thanks in advance,

Onur Tabaki

Avoid using full of URL string starts with "j2e:"

We have discussed though email, I post here for reference.

The URL start with ‘j2e:’ should be unknown to other library. So, please use this style:


The main startup class could not be found

I get the following error when i run the *.exe file only on Windows XP:  The main startup class could not be found

I don't use any libraries and the jar file contains only one main class which produces a text file.

I create the *.exe file with a licenced version (not trial) with Windows 7.

On Windows 7 runs without any problems. However on windows XP shows the above message.

I tried to create it by checking the XP manifest at the last screen of the wizard but it doesn't run also.

I tried not to encrypt and hide files and classes but i had no success either.

Is there anything else i can try?

Maybe because of the version of class file

Maybe the version of JDK which you compile the class files with on Windows 7 is higher than the version of JRE which you run with on Windows XP.

If so, please use a -target parameter when 'javac'.

java is backwards compatible....

since java is backwards compatible why i should specificaly define the target jre since it should run in any older version? furthermore, the jar file runs fine both on win7 and XP. only the exe file doesn't run on xp.

Is there any other exceptions

Is there any other exceptions shown when "The main startup class could not be found"?

The target of class is one of the possible reasons I thought. The java is not backwards compatible if you did not use a "-target" parameter when compile, please refer to

If the target of the class is not the reason, if you would like to, you can send me your exe file or contact me directly through email or skype: .

I Can't Activate the software


I bought this software jar2exe in Jun 26, 2012 22:35. I Lost my HD and I needed reinstall. When I fill the Register User and Register Key on softwate to activate it, I receive the massage: ACTIVATE FAILED. Tour Trial period has 30 days left.

Please, I need your help to resolv this question.


Edison Rangel



A few weaks ago i have installed trails version of jar2exe v2.0.6, for a few weaks i worked fine, 

but today it display an ClassNotFoundException, and it says that can't find class abc (as an example) this was fine, but now not working.

actually i am instanctiating the class using Class.forName("className").

trails time is not finished yet, 

the configuration is as below:

min jre: 1.7

app type : Windows GUI application

class file encryption: Encrypt and Hide class files

I dont know why it worked till yesterday, and now it does not work.

A special ClassLoader is used to load protected classes

Dear Hassany,

Thank you for your message.

If a class is 'encrypt and hide' by Jar2Exe, it is loaded by a special native ClassLoader. A class which is not 'encrypt and hide' cannot load a 'encrypted' class. That is to say, if you call Class.forName("className") within a un-encrypted class for a protected class, it may fail.

The solution is to use "Thread .currentThread() .getContextClassLoader()" to load the class instead.

A program with a ClassLoader is usually a bit complex and abstract. So there may be somewhere else that cause the failure. Please contact me if your problem not resolved or you have any other ideas.

Thanks a lot.

Sswater Shi

Problem solved

Thanks for your comment, I have reviewed my build mechanism, i found the problem with the ant builds, the ant build task did not compile the files, :) i do not know why; i worked perfect till my previous builds, and without changing any configuration or ... i skipped compiling the source files,

However i findout that the problem is not with the jar2exe, and that sounds good to me,

Thanks for you greate product

Exe Not Work

1 ) I am Obuscate my .jar file
2) I used .dll lib which on dirctory and i am using JNA.jar
Generated .exe file not work


  1. After obuscated, please make sure the obuscated jar file still runs at command line by "java -cp yourjar.jar" or "java -jar yourjar.jar".
  2. The dll should be along with the exe file in one same directory.

Contact me ( if your problem not resolved, or we can discuss on IM (Skype or GTalk)


its work

Thanks its work  i put .dll on the same dirctory of .exe and its work


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