How can I package my Java application into an executable jar that cannot be decompiled (for example , by Jadclipse)?
You can't. If the JRE can run it, an application can de-compile it.
The best you can hope for is to make it very hard to read (replace all symbols with combinations of 'l' and '1' and 'O' and '0', put in lots of useless code and so on). You'd be surprised how unreadable you can make code, even with a relatively dumb translation tool.
This is called obfuscation and, while not perfect, it's sometimes adequate.
Remember, you can't stop the determined hacker any more than the determined burglar. What you're trying to do is make things very hard for the casual attacker. When presented with the symbols O001l1ll10O, O001llll10O, OO01l1ll10O, O0Ol11ll10O and O001l1ll1OO, and code that doesn't seem to do anything useful, most people will just give up.
First you can't avoid people reverse engineering your code. The JVM bytecode has to be plain to be executed and there are several programs to reverse engineer it (same applies to .NET CLR). You can only make it more and more difficult to raise the barrier (i.e. cost) to see and understand your code.
Usual way is to obfuscate the source with some tool. Classes, methods and fields are renamed throughout the codebase, even with invalid identifiers if you choose to, making the code next to impossible to comprehend. I had good results with JODE in the past. After obfuscating use a decompiler to see what your code looks like...
Next to obfuscation you can encrypt your class files (all but a small starter class) with some method and use a custom class loader to decrypt them. Unfortunately the class loader class can't be encrypted itself, so people might figure out the decryption algorithm by reading the decompiled code of your class loader. But the window to attack your code got smaller. Again this does not prevent people from seeing your code, just makes it harder for the casual attacker.
You could also try to convert the Java application to some windows EXE which would hide the clue that it's Java at all (to some degree) or really compile into machine code, depending on your need of JVM features. (I did not try this.)
GCJ is a free tool that can compile to either bytecode or native code. Keeping in mind, that does sort of defeat the purpose of Java.
A little late I know, but the answer is no.
Even if you write in C and compile to native code, there are dissasemblers / debuggers which will allow people to step through your code. Granted - debugging optimized code without symbolic information is a pain - but it can be done, I've had to do it on occasion.
There are steps that you can take to make this harder - e.g. on windows you can call the IsDebuggerPresent API in a loop to see if somebody is debugging your process, and if yes and it is a release build - terminate the process. Of course a sufficiently determined attacker could intercept your call to IsDebuggerPresent and always return false.
There are a whole variety of techniques that have cropped up - people who want to protect something and people who are out to crack it wide open, it is a veritable arms race! Once you go down this path - you will have to constantly keep updating/upgrading your defenses, there is no stopping.
This not my practical solution but , here i think good collection or resource and tutorials for making it happen to highest level of satisfaction.
A suggestion from this website (oracle community)
(clean way), Obfuscate your code, there are many open source and free
obfuscator tools, here is a simple list of them : [Open source
obfuscators list] .
These tools make your code unreadable( though still you can decompile
it) by changing names. this is the most common way to protect your
code.
2.(Not so clean way) If you have a specific target platform (like windows) or you can have different versions for different platforms,
you can write a sophisticated part of your algorithms in a low level
language like C (which is very hard to decompile and understand) and
use it as a native library in you java application. it is not clean,
because many of us use java for it's cross-platform abilities, and
this method fades that ability.
and this one below a step by step follow :
ProtectYourJavaCode
Enjoy!
Keep your solutions added we need this more.
Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
Sight is one of the senses most programmers take for granted. Most programmers would spend hours looking at a computer monitor (especially during times when they are in the zone), but I know there are blind programmers (such as T.V. Raman who currently works for Google).
If you were a blind person (or slowly becoming blind), how would you set up your development environment to assist you in programming?
(One suggestion per answer please. The purpose of this question is to bring the good ideas to the top. In addition, screen readers can read the good ideas earlier.)
I am a totally blind college student who’s had several programming internships so my answer will be based off these. I use windows xp as my operating system and Jaws to read what appears on the screen to me in synthetic speech. For java programming I use eclipse, since it’s a fully featured IDE that is accessible.
In my experience as a general rule java programs that use SWT as the GUI toolkit are more accessible then programs that use Swing which is why I stay away from netbeans. For any .net programming I use visual studio 2005 since it was the standard version used at my internship and is very accessible using Jaws and a set of scripts that were developed to make things such as the form designer more accessible.
For C and C++ programming I use cygwin with gcc as my compiler and emacs or vim as my editor depending on what I need to do. A lot of my internship involved programming for Z/OS. I used an rlogin session through Cygwin to access the USS subsystem on the mainframe and C3270 as my 3270 emulator to access the ISPF portion of the mainframe.
I usually rely on synthetic speech but do have a Braille display. I find I usually work faster with speech but use the Braille display in situations where punctuation matters and gets complicated. Examples of this are if statements with lots of nested parenthesis’s and JCL where punctuation is incredibly important.
Update
I'm playing with Emacspeak under cygwin http://emacspeak.sourceforge.net I'm not sure if this will be usable as a programming editor since it appears to be somewhat unresponsive but I haven't looked at any of the configuration options yet.
I'm blind, and have been programming for about 13 years on Windows, Mac, Linux and DOS, in languages from C/C++, Python, Java, C# and various smaller languages along the way. Though the original question was around configuring the environment, I think it's best answered by looking at how a blind person would use a computer.
Some people use a talking environment, such as T. V. Raman and the Emacspeak environment mentioned in other answers. The more common solution by far is to have a screen reader which runs in the background monitoring OS activity and alerting the user via synthetic speech or a physical braille display (generally showing somewhere from 20 to 80 characters at a time). This then means a blind person can use any accessible application.
So, I personally use Visual Studio 2008 these days, and run it with very few modifications. I turn off certain features like displaying errors as I type since I find this distracting. Prior to joining Microsoft all my development was done in a standard text editor like Notepad, so once again no customisations.
It is possible to configure a screen reader to announce indentation. I personally don't use this, since Visual Studio takes care of this, and C# uses braces. But this would be very important in a language like Python where whitespace matters. Finally, Emacspeak does make use of different voices/pitches to indicate different parts of syntax (keywords, comments, identifiers, etc).
I am blind and have been a programmer for the last 12 years or so. Currently am a senior architect and work with Sapient Corporation (a cambridge-based consulting company creating both Web-based and thick client based enterprise solutions).
I use several screen readers but mostly stick with Jaws for windows and NVDA.
I have mostly worked on the Microsoft platform and visual studio as my environment. I also use tools like the MS Sql enterprise studio and others for DB access, network monitoring etc.
I tried to spend some time with emacspeak but since my work was mostly based on the MS platform, never really spent a lot of time there.
I have also spent a couple of years working on C++ on linux - mostly used notepad or visual studio on windows for all the coding and then samba to share files with the linux environment.
Also used borland C for some experimental stuff. Have recently been playing around with python, which as other people have noted above is particularly unfriendly for a blind user because it is written using indentation as the nesting mechanism. Having said that, NVDA, the most popular open source screen reader is written completely using python and some of the commiters on that project are themself blind.
A particularly interesting question I get frequently asked as an architect is how do I deal with diagrams - UML and visio and rational rose etc. Visio is probably the most accessible diagraming tool out there. I was able to write jaws scripts to read rational rose diagrams for me. I've used a tool called T-dub (technical diagram understanding for the blind) developed by some german university for accessing UML 2.0 diagrams. Have used a java-based ugly tool called magic draw for doing model-driven development and was a commiter on the androMDA project and helped develop the .Net code generator from a UML model.
In general, I find that I thrive most in a team environment where I can work on my strengths. For example, while a diagram is extremely useful to communicate/document a design, the actual design process involves a lot of thinking and brainstorming and when the design has been thought out, one of your team mates can help you quickly put together a neatly drawn picture out of it.
People incorrectly mis-construe the above to be lack of independence or ability while I see this as pure inter-dependence -- as in I am sure that the team mate alone could never have come up with that design on his/her own and in-turn, if I depend on him to document the design, so be it.
Most hurdles I face are tool-based inaccessibility. For example all oracle products have been progressively declining in accessibility over the years (shame on them) and a team environment basically allows me an extra layer of defense against these over and above my screen readers and custom scripts.
I am a blind developer and I work under Windows, GNU Linux and MacOS X. Each of platform has different workflows for blind users. This depends on the screen reader that the blind developer uses.
Development tools are not completely accessible for blind developers. I can type code and use compiling functions in all IDEs but there are many problems if I have to design an interface using designing tools as Interface Builder, XGlade or other. When I was developing with Borland Delphi I could add a control, a Button for example, and I could modify each visual attribute of the control using object inspector window. Many IDEs use object inspector windows to modify visual and non visual attributes but the problem for a blind developer is add new controls because the method to add a new control consists of dragging and dropping a control from the palette to the canvas. Visual studio 200x uses alternative methods to do this but the interface of the IDE changes in each new version and this is a big problem because screen readers for Windows need special support, using scripts, to identify each area of some non standar applications. A blind developer can use Visual studio 2008 with his screen reader but when a new version of this IDE appears he has to wait for a new version of scripts for this version of the IDE.
Xcode with Interface builder has no alternative for dragging and dropping tasks yet. I asked it to Apple many times but they are working in other things. I published 3 apps in the App store (Accessible minesweeper, accessible fruitmachine and Programar a ciegas RSS) and I had to design all the interface by code. It's a hard work but I can manage all features of each control.
Eclipse has an accessible code editor but other development tools as debug console,plugins for designing or documentation area present problems for assistive tools for blind users.
Documentations is a problem for blind developers too. Many samples and demonstrations use images to show the explanation (set the environment settings as you can in the picture)
I think the question is not being blind. The question is the companies and development groups think accessibility affects final software but it doesn't affect development software. They think a blind user should be a client but a blind user can't be a development mate.
Blind associations ask accessibility for products and services but they forgot blind developers. Blind people can work as lawyers, journalists, teachers but a blind developer is a strange concept even for the blind. Many times I feel alone because some blind friends of mine can't understand my work.
You can read my opinion about this issue in this article, in Spanish, in my blog http://www.programaraciegas.net/2010/11/05/la-accesibilidad-en-crisis-para-los-desarrolladores-ciegos/
there is a translation tool in the web page. Sorry but I didn't translate it.
Emacs has a number of extensions to allow blind users to manipulate text files. You'd have to consult an expert on the topic, but emacs has text-to-speech capabilities. And probably more.
In addition, there's BLinux:
http://leb.net/blinux/
Linux for the blind. Been around for a very long time. More than ten years I think, and very mature.
Keep in mind that "blind" is a range of conditions - there are some who are legally blind that could read a really large monitor or with magnification help, and then there are those who have no vision at all. I remember a classmate in college who had a special device to magnify books, and special software she could use to magnify a part of the screen. She was working hard to finish college, because her eyesight was getting worse and was going to go away completely.
Programming also has a spectrum of needs - some people are good at cranking out lots and lots of code, and some people are better at looking at the big picture and architecture. I would imagine that given the difficulty imposed by the screen interface, blindness may enhance your ability to get the big picture...
Hanselman had a really interesting podcast with a blind developer recently.
I worked for the Greater Detroit Society for the Blind for three years running a BBS tailored for blind access and worked with a number of blind users on how to better meet their needs, and with newly blind users to get them acclimated to the available hardware and software offerings that were available at the time. If nothing else, I at least learned to read Braille as a hedge against the case where I ever wound up in the same situation!
The majority of blind computer users and programmers use a screen reader of some sort. Jaws in particular is popular. Fortunately, most major applications these days offer some form of handicapped access. You may have to tune your environment slightly to cut down on the chatter, e.g. consider disabling Intellisense in Visual Studio.
A Braille display is less common and is comparatively much more expensive and can show 40 or 80 columns of text, and can be used when exact positioning/punctuation is important. While a screen reader can be configured to rattle off punctuation, a lot of people find it distracting, and it is easier in many cases to feel your way through it. Jaws can be configured to drive the display, so you're not juggling accessibility applications.
Also, a lot of legally blind users still have some modicum of sight left to them. Using high contrast backgrounds and the magnification functionality can help a lot of these users.
Using ToggleKeys in Windows will let you hear when you accidentally tap one of the modal 'caps lock', 'num lock', 'scroll lock', etc. keys as well.
I know at least one Haskell programmer who uses a screen reader and who explicitly programs without using Haskell's layout rules, and instead opts to use the rather non-idiomatic, but supported {;}'s instead, because it is easier/less distracting for him to get his screen reader to read off punctuation than for him to figure out exact indentation that complies with Haskell's layout rules. On that same note, I've heard some grumbling from a couple of blind programmers about when they have to write Python.
Ultimately, you learn to play on your strengths.
I can't recall the source, but I've heard/read about a form of audible syntax "colouring" - so that instead of a string assignment being read as
foo equals quote this is a string quote
the string part would be read with a different pitch or voice to make the separation of elements clearer.
One place to start is the Blinux project:
http://leb.net/blinux/
That project describes how to get Emacspeak (editor with text-to-speech) and has a lot of other resources.
I worked with one person who's eye sight all but prevented them from using a monitor - they did well with Screen reader software and spent a lot of time using text based applications and the shell.
Wikipedia's list of screen reader packages is another place to start: http://en.wikipedia.org/wiki/List_of_screen_readers
I'm a postgraduate student in Beijing,China. I major in computer science and a lot of my work is programming.
I am born with low sight, I need to use magnifying tools to see fonts on screen clearly. I use microsoft's mgnify tools on windows and use compiz's magnify plug in if on linux. I usally set the tool to magnify as three times many as the original font size.
For me maginify tools is ok, the main problem is the speed,I have to move mouse to keep cursors follow the text I'm looking at, microsoft's magnify provides a option of "auto follow the text edit points",that set me from continuously mouse movement when editting or coding. But it doesn't always works because of the edit software or IDE may not support that.
Magnifying tools on linux are hard to use. The KMag come with KDE has a terrible refresh rate which make my eyes unconfortable, compiz's magnifying plugs which I'm using now is OK,but has no function of auto focus(focus auto following).
iOS provides quite perfect solution for me with full screen magnifying, especially on ipad's 9.7 inches screen. there auto focus is not necessary because I hardly use them to code or do other edit stuff.
Android provides very little accessibility functions, only like shake feedback, which is useless for me.
there is no any kind of good magnifying tools on android , not to mention advance function like full screen magnify on iOS.
I used to study Qt, want to build a useful magnify tools on linux, even on android. But hardly have some progress.
When I was in grad school, we had a member of our research team who was blind. He was a bit older, maybe mid-40s. He told us about how he programmed his first computer (which was well before text-to-speech was common) to output the contents of the screen in Morse Code. To overcome the obvious chicken-and-egg problem, he had to completely rewrite the code each time through from scratch until it was working well enough for him to have it read back to him.
Now he uses text-to-speech, though he plans the code very thoroughly before actually writing any of it, to minimize the debug loop.
He was also pretty good at giving PowerPoint presentations that, despite his lack of sight, were just about as well formatted as any sighted presenter's.
This blog post has some information about how the Visual Studio team is making their product accessible:
Visual Studio Core Team's Accessibility Lab Tour Activity
Many programmers use Emacspeak:
Emacspeak --The Complete Audio Desktop
Back in New Zealand I knew someone who had macular degeneration, so was partially sighted. He's a very talented programmer and wound up using Delphi because he could work by recognizing word shapes This was easier to do with a Pascal-like syntax than a C-ish squiggly bracket one. He has a web site, but doesn't seem to mention macular degeneration at all, so I won't name him.
I'm blind and from some months I'm using VINUX (a linux distro based on Ubuntu) with SODBEANS (a version of netbeans with a plug-in named SAPPY that add a TTS support).
This solution works quite well but sometimes I prefer to launch Win XP and NVDA for launching many pages on FireFox because Vinux doesn't work very well when you try to open more than 3 windows of FireFox...
As many have pointed out, emacspeak has been the enduring solution cross platform for many of the older hackers out there. Since it supports Linux and Mac out of the box, it has become my prefered means of developing Windows egnostic projects.
To the issue of actually getting down syntax through an auditory one as opposed to a visual one, I have found that there exists a variety of techniques to get one close if not on the same playing field.
Auditory icons can stand in place for verbal descriptors for one example. You can, put tones for how far a line is indented. The longer the tone, the further the indent. Since tones can play in parallel with text to speech, the information comes through in the same timeframe and doesn't serialize the communication of something so basic.
Braille can quickly and precisely decode to the user the exact syntax of a line. This is something more useful for people who use braille in daily life; the biggest advantage is random access to the contents of the display. Refreshable units typically have router keys above each character cell which can place the cursor to that cell. No fiddling with arrow keys O(n) op vs O(1) access.
Auditory dimensionality (pitch, rate, volume, inflection, richness, stress, etc) can convey a concept (keyword, class, variable, error, etc). For example, comments can be read in a monotone inflection...suiting, if I might say so :).
Emacs and other editors to lesser extents (Visual Studio) allow a coder to peruse a program symantically (next block, fold block, down defun, jump to def, walk up the parse tree, etc). You can very quickly get the "big" picture of the structure of an entire project doing this; with extensions like Cedet, you can get the goodness of VS/Eclipse/etc cross platform and in a textual editor.
Could probably go on and on, but that in a nutshell, is the basis of why a few of us are out there hacking away in industry, adacdemia, or in our basements :).
A group of students from Southern Illinois University Edwardsville and Washington State University are working on a programming language for the blind:
http://www.youtube.com/watch?v=lC1mOSdmzFc
harald van Breederode is a well-known Dutch Oracle DBA expert, trainer and presenter who is blind. His blog contains some useful tips for visually impaired people.
What in the world would a braille keyboard even be??
There are such things as braille writers but you would never use one as an input device for a computer.
If you're simply talking about a keyboard with the braille symbols on it this would also be a very bad idea. You're going to have a lot more keys to reach while typing and it would still be slower.
Touch typing is NOT a visual skill, a blind person can do it just as well as a sighted person.
I think that this would work well in extreme programming using the pair programming principle. If you're making software for blind people, who better to make it then someone who would literally be in touch with the business requirements, so I don't think it's very far fetched at all.
As for writing code, well unless there was some kind of feedback I think a person may struggle with syntax. Audio feedback may help to a point though.
NVDA is a good open source screen reader for win.
What about inventing some kind of device that you plug in a usb port and that would be basically a "sheet of rubber" that would modify itself to show brail of your code, allowing blind people to read it instead to hear it?
There are a variety of tools to aid blind people or partially sighted including speech feedback and braillie keyboards. http://www.rnib.org.uk/Pages/Home.aspx is a good site for help and advice over these issues.
Once I met Sam Hartman, he is a famous Debian developer since 2000, and blind. On this interview he talks about accessibility for a Linux user. He uses Debian, and gnome-orca as screen reader, it works with Gnome, and "does a relatively good job of speaking Iceweasel/Firefox and Libreoffice".
Specifically speaking about programming he says:
While [gnome-orca] does speak gnome-terminal, it’s not really good enough at
speaking terminal programs that I am comfortable using it. So, I run
Emacs with the Emacspeak package. Within that, I run the Emacs
terminal emulator, and within that, I tend to run Screen. For added
fun, I often run additional instances of Emacs within the inner
screens.