is it possible to run java app on linux (with installed java and etc) server with this execution of a command inside the java application?
System.load("path to .dll");
And..
www.mono-project.com can help me do my task for this application?
DLLs are Windows-specific native libraries. You cannot normally use a Windows DLL on a non-Windows operating system such as Linux. You'll need to have a Linux version of the DLL; this normally has the extension .so.
The Mono project is an open-source implementation of Microsoft's .NET framework that runs on Linux (and other non-Microsoft operating systems). It does not help you to run arbitrary DLLs on non-Windows operating systems.
I'm not sure if this will work on Mono but you might want to look at:
Launching an application (.EXE) from C#?
And here is a Mono example:
mono Process.Start how to find bash?
I'm wondering did you even do a search? :)
Related
As far as I know, I can run .mex files on Linux that were generated on Windows by installing Matlab Runtime on Linux (correct me if I am wrong). But what if I want to use a MATLAB generated java package, that was generated on Windows, on a Linux (like Ubuntu)?
Objective:
I have to test a feature that uses audio processing. If test is successful, we will buy the products we need. At the moment I have my requested license on Windows, since the requested license have machine specific limitation, I am able to generate some test java code on my Windows machine, now the application is to be deployed on android, so I learnt from google that it needs matlab runtime to run or compiler to use converted/generated code. Android system has no MCR or simple Matlab Runtime installation support, so I moved to this solution.
Use a linux to host servlet that takes some input from android, do processing return answer in terms of json or text. Now my java package is generated using Windows machine, and I am lost.
From my knowledge this code-convert-servlet-deploy-once approach is cost effective than MATLAB Production Server, since we have to buy license once for the specific products. Remember licensing phase is after we test if this approach is giving us desired results.
Specs:
Windows 10
MATLAB 2016a (Trial)
MATLAB products (Compiler/sdk, Signal Processing/Audio Processing Toolbox)
Package made using JDK 1.7.x (Exactly matching MATLAB jdk/jre version on Windows)
Ubuntu 16 Desktop (with Oracle jdk 8_101 installed, also MATLAB Runtime installed, I can also work with jdk 7.x (same as MATLAB used on Windows when generating package))
Questions:
How can I use this java package in Linux when I create a java program?
What software + licenses are needed to make it possible?
Should I install MATLAB ON Linux machine, generate Java Package ON Linux machine and use that package in java program ON same linux machine? ( I think I will need to request license for it again )
Are there any other methods? Am I missing something?
Java packages generated by MATLAB Compiler SDK are in general cross-platform - however, they may call mex files, or other libraries, that are platform-specific, and if they do the Java package as a whole will end up being platform-specific.
You aren't entirely clear about whether you're calling mex files or not; and you may be calling platform-specific libraries without realising it (for example, Signal Processing Toolbox might call out to some library for some of its operations).
In addition, your comment about being "able to run mex files on Linux that were generated on Windows by installing the MATLAB Runtime on Linux" is confused - mex files are not cross-platform, and the don't use MATLAB Runtime at all.
So with respect to platforms - you may be able to use a Java package generated on Windows on Linux, so long as it doesn't call any Windows-specific mex files or libraries. But if you generate it on Linux, you can rule that issue out, so it will be easier for you if you use the same platform for compilation and execution. It should be fairly easy for you to reassign your MATLAB license to a Linux machine to do that.
Am I missing something?
Yes: the way you're proposing to do things is very unlikely to scale well. If you have a Java servlet on your Linux server along with a Java package generated by MATLAB Compiler SDK, then whenever you make a call to the servlet it will make a call to the Java package, which will start up the MATLAB Compiler Runtime (MCR), run your MATLAB code, return the answer to the servlet, and then shut down the MCR.
The MCR takes quite a long time to start up (nearly as long as MATLAB). So each call will take rather a long time, just due to MCR startup times.
So you can get around that by creating some sort of utility tool that will start up a an MCR and keep it there, and pass through requests and return answers to the servlet.
But then you've only got one MCR - what happens if you get multiple requests at once? They'll be queued up (or dropped) and it won't scale. So you'll need to improve your utility tool, so that it manages a pool of MCRs and passes requests through to a free one, load-balancing them as it goes.
But then what happens if an MCR crashes, or runs ouot of memory? The utility tool will need to monitor that possibility, and restart any crashed ones.
And you'll need some extra stuff that will enable you to administer all that stuff conveniently.
Once you've done all that (which will be hard), you'll realise that you have now pretty much written MATLAB Production Server. I know it's expensive, but you might like to take another look at it before committing to the solution you're considering.
I want to develop a cross platform application.
Is Java cross platform? I mean, can I develop a Java application in Windows and use it in Mac OS X and Linux?
If yes, how?
I find application written in Java, has two setup file one for Windows and other for Mac. This confuses me.
Any illustration or suggestion will be highly appreciated.
Is Java a cross platform?
Java is cross platform in the sense that a compiled Java program runs on all platforms for which there exists a JVM. (This holds for all major operating systems, including Windows, Mac OS and Linux.)
I mean I can develop Java application in windows and use it in mac and Linux?
Yes, this is possible.
This (and the security aspect) is one of the main advantages of running the programs in a virtual machine.
If yes how?
Write your application in Java (In .java files)
Compile your application using Eclipse or javac (into .class files)
(Optionally) Bundle your .class files in an executable (.jar file)
The very same .jar file can be distributed and executed on Windows systems, Mac systems, etc.
I find application written in Java, has two setup file one for windows and other for mac. This confuses me.
This is because some applications rely on platform-specific features. They are then bundled with different platform-specific libraries.
Unless you're developing an application that itself relies on platform-specific features, (such as for instance low-level system calls), you should be able to do just fine with ordinary Java.
Important comment by #Peter Lawrey:
It can be while the application is platform independent, the setup program is not. e.g. IntelliJ has three platform specific installers which are not written in Java, but have a zip which you can just unzip on any platform and it will work.
You can run Java applications on every device that has a JVM. If it does not, you're out of luck.
The comment from Oded is important. C and C++ have compilers on lots of devices.
Java byte code won't need to be recompiled when you switch platforms.
C and C++ will require that the developer recompile the application before distributing it to the target system, but once that's done clients will be able to run without an issue.
The problem of platform-specific customizations and settings has to be dealt with no matter which language you choose. The more your application depends on platform-specific features, the less portable it will be.
UPDATE:
Let's revisit the original words in the question:
I want to develop a cross platform application.
Here's the objective - a direct quote. No details about web, mobile, or desktop app.
Is Java cross platform? I mean, can I
develop a Java application in Windows
and use it in Mac OS X and Linux?
Define "cross platform". Sounds like the bias here is "byte code portability". C/C++ can't do that, but "source code portability" is certainly possible as long as you stick to ANSI C/C++ and refrain from using vendor extensions.
Java's claim to fame from the beginning has always been byte code portability. That's what the JVM gets you. That does not mean your whole application will be portable, because you might not have managed other dependencies well.
If I substitute "C/C++" for "Java in that bloc, then cross platform means something different. I cannot pick up a .exe or .so compiled for one platform and expect to run it on another, but if I create an .exe or .so for each platform and make them available it's certainly possible to make the same source code runnable on multiple platforms.
If yes, how?
If you have packaged your Java app as a JAR, you can put that on any platform you like.
If you have multiple C/C++ .exes for the platforms you're interested in, you can certainly run it when you need to.
There is an important caveat with regard to Java portability. "Business logic" (non-UI stuff) is quite portable, but there are at least a half-dozen different (and incompatible) user interface paradigms for Java, so, eg, Java code written to run on an Android (even ignoring Android's incompatible JVM) won't run on a Nokia phone, and code for either one will not run on a desktop PC.
But there's no other language that does better, to my knowledge.
Yes, Java written and compiled on one OS can run on another OS. There are JVMs available for many modern operating systems.
Java apps are packaged as .jar files. These can run on any operating system that implements the correct Java Runtime Environment for the application, provided the user has installed that JRE (JREs are provided to users for free).
The precise procedure for running the app is different for each operating system.
The Java Development Kit provides libraries that allow system functions (e.g. file operations, user interfaces) to be invoked that ought to work on any OS. However the precise behavior may vary (in a similar way to how a website can look different in different browsers). Also, Java apps may have a 'look and feel' that does not precisely match the look and feel of applications designed specifically for that OS.
It depends what you mean by "cross-platform". Java code can be compiled to byte-code binary class or jar files on any OS supporting the JDK and run on any platform supported the JRE. However, most compiled languages can be compiled on any platform provided the designers has catered for it. Java is more easily portable than, say, C++, but that doesn't mean C++ code won't be able to compile on any platform.
In other words - don't choose your language on this single feature alone. Choosing the best language for your application would be a better way of going about it. Perhaps a scripting language would be best for you. Maybe post another question asking what language to use to solve your specific problem.
I wrote a little game in Java with sound.
I've used standard library (AudioInputStream and Clip classes).
The program works very good with Windows XP, BUT I haven't got the sounds with Windows Seven or Linux Ubuntu.
Java 6 was installed for all those OS, and I've compiled the program with the standard compiler JAVAC.
So Java is not so "cross platform".
JAVA is not really cross-platform because is just a design, some JAVA implementations can be cross-platform but it really depends on the JAVA implementer.
SUN/Oracle makes the JAVA standard implementation for Windows, MAC and Linux and if you build programs with their JDK you should run the programs with their JRE, if you try to run it with other JRE there might be compatibility issues.
This can be seen more in the mobile, some phone makers won't make a full implementation of JAVA because hardware limitations or because they want to control the device's software, they carry the JAVA logo but you must use their own JDK and those programs could not run outside of their JVM implementation.
Another issue with JAVA is that some functionality could be deprecated and what ran in some specific version of the JRE could not run in newer versions or run in a different way.
The big problem is when we are talking about mobile apps. For desktops OS, java can run perfectly, but for mobile devices, developers can, practically, only create for Android. There are tools like Totalcross that helps java developers to create apps to iOS and Android. The focus is maintain the WORA assumption to every platform, even mobile.
I wonder if you can load a DLL, of Windows operating system (for example, user32.dll), in an application (in any programming language) with a Linux operating system.
The DLL would be in a directory on the Linux file system.
Thanks for the help.
Greetings!
Yes, you can load a DLL and call its functions by using an appropriate wrapper library, but that's fundamentally useless if the DLL itself has dependencies on the platform which are not present. This approach is used for things like closed-source video codecs, where no (nontrivial) dependencies exist.
User32.dll is of course, part of the OS and intrinsically linked to many NT kernel functions, none of which exist in Linux. Wine does not make use of the Windows user32.dll, but provides its own version which gives equivalent functionality.
Loading Windows' user32.dll would definitely not be useful, as it is mostly going to be a wrapper for other DLLs, processes (for example CSRSS) and kernel calls which aren't present under Linux. You could load and use Wine's one though.
No. The architectures are fundamentally different.
I note your question is tagged C++. If it was a .net DLL (built with CLR bytecode) then you could reference it via an application running under Mono.
It's possible if you write a wrapper for it. That's how the win32 codecs work on Linux. Also Wine uses many DLLs.
You could probably do a custom Wine build (home page, Wikipedia page) for your application. We're talking about a big hammer here, though. :-)
DLL is a format for windows (i.e. it MS implementation of shared library concept).
It is not in a format that Linux understands.
Linux uses the ELF format for dynamic libraries.
Why do you want to do this? To execute a program (.exe) that uses that DLL? In that case you need a Windows emulator on your Linux machine, such as wine.
I have a java application that I want to release as an exe or dwg etc so that users on different platforms can double click it and get it to start running.
But for my code to work really well I need it to work as a windows service and whatever the equivalent of this in other OS are.
Using Java web start is not a solution because as I understand it, if the client machine shuts down then the user will have to again double click on the exe.
I have tried java service wrapper but I can't see how to make it releasable.
Thanks
Pranabesh
If a commercial tool is acceptable for you, I'd recommend install4j. It can produce installers for the most common plaftforms, which specifically support installing the application as a service.
Quote from their Features page:
install4j offers full support for generating and installing services (daemons). For services, install4j generates service executables on Windows, startup items on Mac OS X and start/stop scripts on Unix/Linux platforms.
Java Service Wrapper is a way to go for Windows/Unix/OSX. I've been using it with no problems for some years. It's a great software and handles JVM crashes/hangs well automatically restarting the service if something bad happens.
What concerns the distribution of the application, I'd recommend NSIS on Windows. It can create a nice installer that will put the files where necessary and run the JSW stub to install the service on the target system. For Unix you can just package it in tar.gz and provide instructions on how to install the service (copy the sh script into /etc/init.d, install it using chkconfig or any other system dependent tool for managing startup scripts). On Mac you should package it into dmg.
You may also try izpack if you want a more cross-platform solution. izpack can run from the java web start, as a native windows application or mac application, check the utilities page.
IzPack is a one-stop solution for packaging, distributing and deploying applications.
It is fully cross-platform and generates a single installer. As such, it is an alternative to native solutions such as platform-specific installers and package managers.
IzPack-generated installers only require a Java virtual machine to run.
You would need to build a release package for each operating system you were to release on.
For Windows, for example, you will need to find an executable wrapper. It's been a while since I've done this, but I remember usign a couple that would actually build an installer as part of the proccess.
Launch4j is one I've just remembered
I am a Mac user who wants to run a few .exe files from my Java process using Process and Runtime classes.
I know that it is not possible to execute .exe files in general in Mac OS X.
Is there a Mac application which can wrap these .exe files so that they can be executed ?
Does Apple provide anything by itself ?
The alternative I am using now is to run the Java process in Windows. Yet, it is cumbersome in general.
Darwine
Edit: I should probably point out that this is not a 100% solution. Virtualized Windows will nearly always work better, through Parallels or some similar virtualization software. But Darwine is free and runs most Windows software acceptably.
Besides wine you can get VirtualBox(free), Parallels($$$) or VMWare($$$).
Well, if it's a .NET application then you can possibly run it with Mono, but I'm betting it's a native binary and you'll have to use something like the aforementioned Wine. I thought it was really cool the first time I ran a .exe using Mono on OSX, it just felt wrong, so I had to share.
I don't know if it exists, but you would need something like wine for OSX. The reason why is that the .exe would nearly certainly use OS specific system calls and library functions.
EDIT: looks like it does exist
java -jar file.exe and monofile.exe both works natively on MACOS with native MACOS java and mono
1)Install Wine and Winebottler from http://winebottler.kronenberg.org/
2)You may have to change the System Preferences >Security & Privacy>Allow Apps downloaded from>Anywhere
2)Click the xyz.exe and select winebottler for running application