Adding command recall to a Unix command line application - java

I'm working on a command line application for Solaris, written in Java6. I'd like to be able to scroll through a history of previous commands using the up and down arrows like many Unix tools allow (shells, VIM command mode prompt, etc).
Is there any standard way of achieving this, or do I have to roll my own?

Yes, use the GNU readline library.

I think you are looking for something like JLine but I've never used it so cannot attest to its quality.
She can apparently deal with autocompletion and command line history, and the last release was recently (feb this year) so it's by no means dead.

ledit is great on linux for that sort of thing. It's probably easily compiled on solaris.
Clarification: ledit wraps the call to your other command line app, and can even be passed a file to persistently store your history.
Here's the homepage: http://cristal.inria.fr/~ddr/ledit/

There is a SourceForge project, http://java-readline.sourceforge.net/, that provides JNI-based bindings to GNU readline. I've played around with it (not used in an actual project), and it certainly covers all of the functionality.

warning: GNU readline is subject to GPL licensing terms:
Readline is free software, distributed
under the terms of the GNU General
Public License, version 2. This means
that if you want to use Readline in a
program that you release or distribute
to anyone, the program must be free
software and have a GPL-compatible
license. If you would like advice on
making your license GPL-compatible,
contact licensing#gnu.org.
In other words, use of Readline spreads the GPL-ness from a library to the entire program. (Contrast with LGPL, which allows runtime linking to a library, and requires open-sourcing only for improvements to the library itself.)
For those of us in the commercial world, even if we're not developing commercial applications, this is a show-stopper.
Anyway, the wikipedia page lists several alternatives, including JLine, which sounds promising.
Just as an aside: I work for a company that designs medical products. We make zero (0) dollars off of PC software. Nearly all our software runs on the embedded systems that we design (and we don't make any money off sales/upgrades of this software, only the products themselves); sometimes we do have software diagnostic tools that can run on the end-users' PCs. (design/manufacture/test software that's not released to customers I would think might be possible to use GPL libraries but I'm not sure) Medical products have fairly tight controls; you basically have to prove to the FDA that it's safe for users, it's not like the end user can decide "oh, I don't like this software, I'll just tweak it or use company XYZ's aftermarket replacement" -- that would leave device manufacturers open to a huge liability.

Related

Java to EXE good or bad idea?

I have been wondering for a long time about converting Java projects to EXE.
The advantages relies in the faster deployment on Windows where the user simply double clicks the EXE and the application is launched where is with Java, he has to run certain commands.
But EXE is really not what the Java was intended for which is portability.
So what do you think, Java to EXE good or bad idea?
I found some interesting article here.
Update
Wow, so may contradicting views so far. I would like you guys to add the pros and cons of the JAVA to EXE.
Since my expertise is with Java Web Start, which is for launching desktop apps. with a GUI, please consider my advice to be targeted mostly at those types of apps.
Other people have commented on the OS specific nature of an EXE. I always have to wonder why people choose Java to develop Windows specific desktop apps., since the Visual Studio software for Windows would probably make both GUI development (no x-plat Java layouts to bend your head around) and deployment (just guessing it can produce an EXE) easier.
OTOH only you can say what is the best development tool/language for this use-case.
As to the potential disadvantages of creating an EXE, I note at the JavaFAQ on EXEs.
There are a number of good reasons not to package your application in an executable. Daniel Sjöblom notes:
It will probably not be any faster. Modern virtual machines don't interpret bytecodes, they actually employ a JIT compiler to produce native, compiled code. Check Sun's site for further information on JIT compilers.
Static compilation increases the size of your application multifold, since all of the libraries you are using need to be linked into the application.
You lose 'free' upgrades to your program. Anytime your user downloads a new faster virtual machine, your app gets a speed boost. If you are using an exe, you will not get this benefit.
Jon A. Cruz details some of the extra steps in the development process required to create an exe. He points out that developers making native exe's need to:
Validate the latest versions of the compilation product from the vendor. If critical bugs are found, it can't be used to build a shipping product until those are addressed. Work that needs to be done each time a revision comes out from the vendor.
Submit the software through a QA cycle. Once engineering thinks things are done, they need to be verified. So every shipping version and update of a product needs to go through complete testing cycles.
Further, since native compilation is per target platform, the QA cycle needs to be done completely for each target platform, which multiplies effort required.
Shelf space. Maybe not a big deal nowadays, but could be.
Then one needs to get all customers to upgrade to the proper version. Either have free updates (in which case the business needs to absorb the cost of producing updates) or alternatively needs to handle clients not all updating.
Jon notes futher: When you ship standard Java bytecodes, VM problems are the responsibility of the platform or VM vendor. However, when you ship compiled binaries, they become your responsibility (even if they're actually bugs in the vendor's compilation product).
...
Of course, my first choice for deploying Java rich client apps. is using Java Web Start. Putting some of the benefits/features of web-start in point form:
JWS provides many appealing features including, but not limited to:
splash screens
desktop integration
file associations
automatic update (including lazy downloads and programmatic control of updates)
partitioning of natives & other resource downloads by platform, architecture or Java version,
configuration of run-time environment (minimum J2SE version, run-time options, RAM etc.)
easy management of common resources using extensions
..
I decided to highlight auto-update since with the gradual shift from apps. delivered on disk to apps. delivered over a network, auto-update is becoming more common. JWS still provides the best update experience (very configurable, mostly transparent to the user) I've seen.
And of course, JWS works on OS' for desktop PCs for which Java is available.
Update
..does Java web apps require internet connection?
(Note that name is 'Java Web Start'.)
Sure it does. At least for the initial installation. Update checks can be specified to continue to launch the previously installed version of the app. if the user is not currently connected.
But then, (in my estimation) there are more machines (such as Netbooks) with no CD/DVD drive, than there are without internet connections. If you want to sell to the larger market, look to the network to deliver the app.
It depends on your needs. We had written a little barcode client scanner app here for our customer. They run it on two Windows-PCs. They are happy having their well-known exe-files. We coded it in Java and created an EXE-file for them.
Both parties are happy with it - so why not doing it?
When there are good reasons for it and nothing against it except dogmatism then it is ok in my opinion.
I am the author of the article you linked to - glad you've found it interesting!
As my article states, and as others have already pointed out in their answers, there are multiple ways to simplify deployment of Java apps - JNLP, EXE wrappers, installers bundling a private JRE, and so on. But true native compilation is the only option that also provides protection against Java decompilers - you simply do not ship the bytecodes.
Of course, that does not make reverse engineering of and tampering with your code impossible, just much more costly in terms of required skillset and time.
As far as application performance is concerned, native compilation can make a big difference if you target embedded systems. This also applies to memory and disk footprint, albeit to a smaller extent. On the desktop you would typically get better startup, but in most other scenarios and aspects the results would depend on your app.
If it has a good reason why not? Even Eclipse has an EXE on windows and (and platform dependent binaries for linux, mac, etc) Of course you loose portability but if that is not important then go ahead.
UPDATE
The question is what do you want to achieve by creating an exe :
Convenience : users on windows prefer to click on icons, this is especially true for the non geeks. On the other hand non geeks don't care what the link does internally if it starts up an exe or something else. You can have an application icon for non native Java applications too. The alternatives would be
Web start
Creating an installer package,e.g.: http://www.advancedinstaller.com/java.html This can also solve the problem of installing the JRE
Performance : If you compile your Java application into a native solution you may gain a bit on performance but it depends on what technology you use. For example Swing tends to be slow but compiling that to native is rather tricky. If you use SWT instead of Swing that is already using native components therefore no need for further native compilation. On the other hand recent JVMs perform very well and can compile java to native to further improve the performance bottlenecks. This is done silently on the background you dont need to worry about that.
Sum : in some cases it might be the only solution, but if you choose the right technologies there will be many Java based alternative solutions to reach the same goal.
The page behind the link in the question is written by a company that sells products that compile java to native code. I would not base a decision on that alone.
The question also says that the advantage of the exe a better user experience, because the user can just double click to launch the application.
That is possible with executable jar file. In fact, its actually quite easy with standard tools in the java runtime. You just have to add a manifest to a jar file, and specify the class with the main in it. You can also specify other jar files in the classpath relative to the location of the main jar file. You can also specify an image to use as a splash screen as a resource.
e.g.
Class-Path: lib/derby.jar lib/derbytools.jar lib/jcalendar-1.3.2.jar l
ib/joda-time-1.4.jar lib/log4j-1.2.14.jar lib/looks-2.2.1.jar lib/swi
ng-layout-1.0.jar
SplashScreen-Image: resources/splash.png
Main-Class: com.you.pkg.app.Main
The basic ant project in Netbeans will do all but the spash-screen for you if you use it. If your some reason you want to do all of that by hand, make sure you understand the format of the manifest file, its a bit finicky.
As Linux, mac., Solaris user I think this is bad idea.
If you want faster deploy on windows, just create installer.
Jar files provide many benefits including:
Compact: The whole application (i.e. all the class files) is stored in one archive file (which can incorporate image and sound files if required).
Ease of use: The application can be run by double-clicking.
Compression: The jar format allows you to compress your files for efficient storage.
Security: You can digitally sign the contents of a jar file. Users who recognise your signature can then optionally grant your software security privileges it wouldn't otherwise have.
I would not convert to exe.
Most Windows applications run from a .exe file (Word, Internet Explorer, FireFox, NetBeans, ...)
Java itself has no support for doing this as the executable file will then be platform dependent (i.e. it won’t run on Macs)
However, there are (free) applications that can do this for you.
Minecraft does it, so it must be a good idea!
All jokes aside, understand that it's not 'conversion' that you are looking for, but using a custom launcher. The article you linked does a nice job of explaining the different approaches and pros/cons of each. As a general idea, it requires the extra work of creating the launcher (and a different version for each different OS architecture), but it gives you a little more control (version checking is a nice feature, also you may update the application jar rather easily, like Minecraft does). Overall it's a good idea if you think it's worth the effort, and the (little) loss in portability.
Edit: the 'Custom Java Launchers And Wrappers' approach is the one that you should use if you don't need the really nifty extra features offered by those below it.
Depends on the user base. If they are tech-related in anyway then giving them a .jar file (which could be run by double click) is a good idea for mobility.
If your users are less techy but you still need it to run on multiple platforms then wrap it as exe for Windows and as .app for Mac.
Important: I would suggest making a script to wrap it into exe, so you run it each time you have a new version.

Voice operated Software development tools

I have been suffering from severe RSI on my hands and wrists and as a full-time Java programmer, and this is becoming a risk to my livelihood. I use Dragon Dictate for the Mac, which does quite a good job of writing English, but speaking to it in Java is very cumbersome due to the cryptic nature of programming languages. Navigating the code is also tricky and can be rather exhausting.
I currently use the Eclipse IDE but haven't found any plug-ins to help in this regard. from what I have read in other posts in this forum (for example, Voice recognition software for developers, and Can i write sql using speech recognition), the approach I should take should be to give Dragon Dictate a custom vocabulary consisting of Java keywords, and to create a number of custom voice triggered commands that correspond to existing shortcut keys (e.g., "navigate to superclass") or sequences of actions that I perform on a routine basis using AppleScript ( e.g., “commit to SVN").
I could just go ahead and implement this (with some difficulty due to physical limitations) but cant help feeling that I would be reinventing the wheel. I mean, surely RSI must be a relatively common problem among programmers, and I would have expected that there might be a plug-in or even, an IDE, that facilitates coding by voice and also associated tasks (for example, debugging the program by stepping through it etc.) I just don't seem to find this anywhere.
If anybody has any suggestions about the Java IDE that I could use (I don't need to use Eclipse obviously) I'll be very interested to hear them.
Alternatively, if anybody uses Dragon Dictate for the Mac and has a command set for Eclipse or another Java IDE that they are willing to share with me, that would also be a great help.
Thanks, Ixent
http://voicecode.io
I recently released VoiceCode, a coding-by-voice solution I created to solve my own RSI issues.
I use it mostly for coding in Sublime Text and Xcode, using the terminal, and other general computer usage. The great thing about this solution is that all the commands can be chained into "command phrases" so you don't have to pause between every individual command like you do with other voice command solutions.
It has builtin support for all standard variable-name formats (snake case, camel case, etc), has builtin commands for every permutation of keyboard shortcuts (ie command-shift-5, command-option-shift-T, and so on), has cursor movement commands, app switching commands, window switching commands, text-selection commands, commands for symbol combos like "=>", "||", ">=", etc, and tons more. Plus it is very easy to add your own custom commands as well.
I work with clients who have DNS. I have created for them scripts for their own work environment. I have experience with DNS and the fustrations which it can cause to navigate.
You are probably right, there might be others like you. But how do you bring them together. It might be best to start a user community. Depending on your contacts, you probably could get funding for leading such a community.
How to Start a Support Group
American Self-Help Group Clearinghouse
There is another article you might be interested in reading.
Good luck
Look at this https://polaris-a.com
"Programmers of the 21st century will know Polaris as a name for a Eclipse IDE voice recognition plugin. It can quickly turn your spoken words into actions.
With Polaris you have ability to control Eclipse IDE main functionality, without the need to use a mouse or keyboard."

How to pack java project?

I have made a java project and want to deliver it to a client but I don't want to deliver it as a jar file as the client can see the source code easily by unpacking the jar file.
How can I pack my java project so client cannot look at the source code or cannot change the source code?
One more thing, Can I integrate a key functionality so that client can only access that software by first registering it with the key provided by me?
Second, can I integrate another functionality through which the software can run only on a single machine through that key?
Remember, the software should still have the cross-platform functionality and if it is not possible then how can I made it for Debian Linux as I have made it on Windows.
To your first point. Why not only jar up the class files? These are in byte code so the client will not be able to view the source.
As to providing a key. This can be done and there are libraries that allow this, but be careful as , to my knowledge at least, there has yet to be developed a DRM system that hasn't been cracked. and most users do not like software restricting what they can do. The same point applies to your third question.
Obfuscators
There are some simple things you can do to make it a bit difficult for a client to get hold of your source code and to enforce per-host (etcetera) licensing. For example, obfuscators make it harder to reverse engineer bytecode files, and license managers support a range of restrictions based on the "keys" that you generate and supply.
The problem is that none of these protect you against someone who is determined to subvert the restrictions are trying to impose. For example, no obfuscator can prevent someone figuring out where your code calls a license manager, and once they know that they can modify the code to subvert any license checking.
Short of locking down the entire execution platform (e.g. turning of the client's ability to run debuggers, read physical devices and so on), there is nothing you can do about this.
A more viable strategy is to include appropriate protections in the software license that you require the client to sign. And accept that there is a risk that you may need to take clients to court if they willfully violate the license agreement.

Old Version of SuperWaba

I was searching for the old versions of SuperWaba, but i can't found anyone on internet, because the newer versions of SuperWaba are commercial, but the old versions are free, then if someone have the SuperWaba SDK free version on archive, please post it here. Thanks!
One more thing: the SuperWaba project with all sources is available at superwaba.sourceforge.net.
But are you sure you can't afford 14.95usd to get a vm and a database? And, honestly, TotalCross is a great piece of software. There are many big companies around the world that adopted it. The next Brazilian Census will be made with it (200 thousands device running on field).
If you're a student, you can just use the demo vm (which expires after 80 hours of continuous use). Then you are allowed to hard reset the device, install it again and use more 80 hours.
regards
Great answer, thanks. I'll like to explain why we do not use GPL. Rick Wild sent us an agreement, when we developed SuperWaba, to allow us to change the license to LGPL. Without this change, no one would be able to produce commercial applications.
In TotalCross, the Java classes are still LGPL.
Regarding why the VM is not GPL/LGPL. The vm was written from SCRATCH, so we are able to put any license we want. We made this specially to not have to be tied to old licenses.
Best regards
guich (TotalCross Lead Developer)
It does indeed look like the bods at SuperWaba have decided to monetize their investment and you now have to buy TotalCross. Even SuperWaba commercial support is gone as of the end of 2009.
If you're not up to shelling out your hard-earned cash for their product, my suggestion would be to look into the Waba SourceForge project here. It's been a while since it changed, but may be the only way to get something for free.
Alternatively, you could actually buy TotalCross. It seems to me that either it's valuable to you (in which case you wouldn't mind paying for it) or not valuable (in which case, why bother with it). There's a TotalCross demo freely downloadable from that site you linked to, so there's no need to shell out cash until you're happy with it.
I'm sorry if that doesn't fully answer your question (I'm not trying to cause offence) but, if you're a professional developer, I'm sure you don't want to deprive other professional developers of their income.
If you think that the TotalCross bods have somehow broken the GPL (I'm presuming here that SuperWaba was based on Waba and may be subject to GPL licencing itself - that may or may not be the case), another avenue may be to contact them and just ask them what they think about that. It may be that they're still bound by the "make source code available" GPL provision and they may give it to you just to avoid any potential problems.

Java on OpenVMS?

We run batch files on our OpenVMS Alpha and Integrity servers. Up until now they have been written in COBOL. As you can imagine there are many reasons why will not be able to maintain that process.
At the same time we have a team of developers that use Eclipse and know Java very well. Is there away to use Eclipse with OpenVMS?
Maybe it's because I don't keep up with COBOL, but I am not sure why you're convinced you have to abandon it. I realize it's not the "in" thing, but if you already have a large code base I'd think at least twice before switching to another language. If it's a lack of developers, I don't think you're going to run out that soon.
That said, googling Eclipse & OpenVMS gave this link:
http://www.sdtimes.com/SearchResult/32973
So it looks like you can still get Eclipse for OpenVMS from eCube. If I'm reading that article correctly, HP seems to want you to go the NetBeans directions. Personally, I'm still using Emacs (and not currently doing any Java), so won't make a recommendation; I just wanted to point out that there are other ways to develop Java than Eclipse.
I didn't find Java for VMS on Sun's site (someone feel free to correct me if you find it), but it looks like you can get the JDK from HP/Compaq at:
http://www.compaq.com/java/download/ovms/1.5.0/index.html
Edit: I meant, but forgot to say: Assuming you're using a JVM on the VMS side, you should be able to development with Eclipse on another platform, and copy the byte code to the Alphas.
Speaking from experience, if you do decide to rewrite your batch processes in Java I'd suggest you use a third party batching framework like Spring Batch instead of 'growing your own'.
Using a framework also constrains you to work within a standard and should provide non-functional requirements like re-runability, transactions and error handling.
We've (re)built a number of batch processes from various technologies to Java using a home-grown framework and I find we end up spending time on fixing/optimizing the framework rather than just focusing on the business logic.
Don't leave Cobol yet - call a-cobol-programmer-thinking-about-switching-to-the-modern-world and make a trade: you teach him Java, He maintains your legacy.
Shell scripts and java usually aren't a great mix. You may want to consider installing a JVM on your VMS servers, and using one of the JVM-hosted languages that handle that case better- jython, jruby, or groovy might be candidates to consider.
Eclipse relies on native Java extensions that do not appear to have been ported to OpenVMS. Don't give up though. Java runs on OpenVMS (at least 1.5 according to a Google search).
NetBeans has a Java only edition that should work on OpenVMS. On the NetBeans Download Page select the OS Independent Zip option for the platform.
Are you running the batch files on your OpenVMS system? If so, HP makes Java available for OpenVMS, not SUN; you will have to look at their site. You can develop your java code on a windows/linux machine and test it on your VMS system; you must be aware of the native extensions that you cannot use on the VMS implementation of Java.
Speaking with some experience in this area, I suggest developing with Eclipse on your Windows/Linux/Mac desktop, and pushing the code out to OpenVMS for testing/deployment. Eclipse won't run on OpenVMS because of some platform-specific components of its GUI.
Some caveats:
Make sure that you are using the same version JVM on your desktop as on OpenVMS.
The case insensitivity in OpenVMS can be a problem when using inherently case-sensitive Java .class files. Package everything in a .jar and deploy it that way.
The attributes on .jar files have to be set correctly or the OpenVMS JVM can't open them. The following command should do the trick:
SET FILE *.jar /ATTR=(RFM:STMLF,RAT:CR)
HP provides both a "fast" JVM and a "classic" JVM. Use the fast VM unless your memory needs are highly variable.
I realize this question is rather old, but I was shocked nobody mentioned this book covering Java on OpenVMS.
https://www.theminimumyouneedtoknow.com/java_book.html
What really matters when using an x86 editor on OpenVMS source is your file transfer software. OpenVMS (and many other midrange ASCII based platforms) use even though most PC developers say LineFeed Carriage Return, the data files typically store it in the other order.
You can read much more about that here:
https://www.logikalsolutions.com/wordpress/information-technology/most-text-editors-get-tabs-wrong/
Your file transfer software will need to perform text mode file transfer changing the line ending characters OR your editor needs to both use and respect the better systems line ending characters. I thought there was something in Eclipse (via plug-in) to handle this. Notepadqq claims to have something.
Note this: They use Eclipse for development, not just editing.
That means they are running and debugging in their own PC based Eclipse universe and that ain't how it's going to work on OpenVMS. They are going to need a terminal into the VMS system and it needs to be a REAL VT-100 terminal emulator, not the worthless free stuff. You can read a little bit more about that here:
https://www.logikalsolutions.com/wordpress/information-technology/diamond-edt-keypad-support/
and here
https://www.logikalsolutions.com/wordpress/information-technology/xterm-and-vt-emulation/
Depending on how old your system is, you might have Pathworks installed and running. Then a system manager can create a directory for each user that they can map as a network drive to the PC. This lets the PC user use the directory like any other network disk and it generally could be configured to handle the line ending issues with text files.
There is no way they can develop on OpenVMS using Eclipse. They can edit files then test on OpenVMS, but they cannot develop within the IDE which I suspect is what they really want to do.
The only GUI that ever existed for OpenVMS was DECWindows. You had to run it on either a VAXStation or a DS model Alpha workstation. I never heard of Eclipse being ported to it. In the latest port of OpenVMS to x86 there is no GUI. It is a server only OS.
Yeah, I spent two decades on the platform and even wrote this book for it.
Yes, there is a version of Eclipse that supports OpenVMS called NXTware Remote. It has support for Java and COBOL languages as well as Fortran, Basic and Pascal.
You can edit OpenVMS files using pretty much any editor, including Eclipse - just use Samba to make OpenVMS directories and files visible to desktops on the network. If you install Java for OpenVMS, then you've got folks using Eclipse, and compiling and running on OpenVMS.
As for ditching Cobol - why? There's still a ton of companies running it, and it will certainly last for decades more.

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