New to java programs so apologies for the noob question. I have written a java program that I run using "java myprog" command in a terminal window. I want to give this program to friend but not sure what that person needs as a minimum to run the program. Can the code be compiled to run completely independently of any java installation my friend may or may not have? Will the other person need to recompile the code?
Option 1
You can give them the compiled output (the .class) file.
They need a version of the JRE (but not the JDK that developers need to compile) that is compatible with the version you used to compile your code. The simplest way is just to match versions. For example, if you're using J2SE 7, then get JRE 7 for your friend.
With this your friend should be able to type java myprog and get the same results as you. If you want your friend to run the program from the command line the same way you do, then this is probably the simplest approach.
So, if on both your machine and your friend's machine you type:
java -version
...and you get the same major version, then you're probably in the right ballpark.
Option 2
You can also create an executable .jar file if you want something your friend can just double-click, but they'll still need a version of the JRE installed, and creating executable JARs can be a bit difficult if you're new to the language. They take some learning and trial-and-error time. This is definitely a more complex approach than option #1.
Option 3
There are compilers that will convert your java program into native code (an .exe file in Windows), but you'll need to know what OS your friend is running, and make sure you're compiling for your friend's OS.
One example of these tools that I heard about years ago is Excelsior JET (though I'm not endorsing it as a tool - just saying that they exist).
This is definitely the most advanced/most difficult of options, and includes even more trial-and-error than option #2, but if you're talking about a really simple program with a single file, then it might be very straightforward.
Of course, Excelsior JET wasn't free last time I checked.
I've written an entire article on this very subject:
Convert Java to EXE - Why, When, When Not, and How
You want to create an executable .jar file. Provided that your friend has Java installed, he can run the program by simply double clicking on the file.
Java programs are usually compiled into Java bytecode - not to a native executable. Once compiled, the resulting class files will be executable on any JVM that is recent enough, regardless of the underlying hardware platform or operating system. In order to have a JVM, however, your friend would typically need to have an appropriate Java Runtime Environment (JRE) installed.
Alternatively, there are ways to distribute a program along with a JRE, but I believe that this approach is not trivial. There are programs, such as launch4j, that can automate the process somewhat, if you want to go that way.
The options given above suggesting giving the .class file and using java myprog may not work if the friend is not located in the directory where myprog.class has been placed, as the class path may need to be specified. So the friend may have to use java -cp path_to_myprog myprog
Related
This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
How can I convert my java program to an .exe file ?
I'd like to create a Windows .exe for a Java program. Previously, I've used JEXECreator for this, but it's not entirely satisfactory because:
The executable sometimes works on the machine on which it was created but not on others.
The program is commercial; if you use the trial version, it adds a nag screen to your application.
I don't need the generated .exe to work if Java is not installed on the target machine (in fact, I think this is impossible).
Any recommendations?
Launch4j perhaps? Can't say I've used it myself, but it sounds like what you're after.
Most of the programs that convert java applications to .exe files are just wrappers around the program, and the end user will still need the JRE installed to run it. As far as I know there aren't any converters that will make it a native executable from bytecode (There have been attempts, but if any turned out successful you would hear of them by now).
As for wrappers, the best ones i've used (as previously suggested) are:
JSmooth
and
Launch4j
best of luck!
If you really want an exe Excelsior JET is a professional level product that compiles to native code:
http://www.excelsior-usa.com/jet.html
You can also look at JSMooth:
http://jsmooth.sourceforge.net/
And if your application is compatible with its compatible with AWT/Apache classpath then GCJ compiles to native exe.
I used exe4j to package all java jars into one final .exe file, which user can use it as normal windows application.
You could try exe4j. This is effectively what we use through its cousin install4j.
The Java Service Wrapper might help you, depending on your requirements.
If Java is installed on the target machine, there is no need to create an .exe file. A .jar file should be sufficient.
I'm trying to use the C++ library Spot (https://gitlab.lrde.epita.fr/spot/spot) in a Java project. I wanted to realize the interface between Java and C++ with JNA (https://github.com/java-native-access/jna). Because the Java application should also run on Windows, I tried to cross compile the library first with
./configure --host=x86_64-w64-mingw32 --disable-python LDFLAGS="-static -static-libstdc++ -static-libgcc"
and then of course make/make install on a Linux system. Because I can't expect the Windows system to have libstdc++/libgcc I wanted to link it statically into the library. My problem is now the following: When I try to open an compiled .exe in Windows, it still tells me libstdc++/libgcc not found. Of course, JNA also gives me an UnsatisfiedLinkException when I try to load the library in my Java program, because the modules are still not found, even though i explicitly linked them statically.
So what am I doing wrong? What else can I try to avoid having libstdc++/libgcc installed on the host system? I am now trying this for a week and have no clue how to overcome this, so a question here is kind of my last resort.
Thanks
this is a kind of weird non programming (but java related) question.
I created a java program (game) using just normal java, and no libraries.
In ordor to double click/open it, you need to have java SDK/JDK (I don't know which) installed.
I tested this multiple times, and in order for my PC and Mac to launch it, you need to install it.
is there anyway to get around this? I know Minecraft doesn't force you to download the JDK.
Here's the link to source code of my game if your interested (no, it is not a virus): http://www.filedropper.com/daplatform
Thanks, Jake
Here's the link to the download of the JDK (Its next to the giant Netbeans download): http://www.oracle.com/technetwork/java/javase/downloads/index.html
What you can do is you can wrap both your program and the JRE required to run it into a single executable for the target platform.
For example your windows installer would include both a windows JRE and your program itself.
Launch4j http://launch4j.sourceforge.net/ lets you wrap a Java program into a windows executable and gives you options about how to handle the JRE, including bundling it.
I made a simple text based game that runs on my computer, but my schools computers have an older version of java and can't run it. I tried compiling the .java file in from the computers command prompt but I can't access where the javac folder is to compile because the school computer blocks everything. The command prompt is even disabled by the administrator unless I open it with a batch file. I tried wrapping the jar with the JRE in Launch4j but the exe does nothing, it loads and that's it, nothing comes up (I think it's because the text game is supposed to run in the command prompt so there is no GUI to print any of the text)
How to get a Java program to run on a computer without modern JRE?
my schools computers have an older version of java and can't run it
Use the cross-compilation options of javac when compiling it at home.
You are running into a bit of a contradiction here; Please take notice on what exactly you are asking:
"How can I run a Java Program without Java?"
Do you get it? You are basically asking "How can I drive a car without the car?"
As for the actual problem, all hope is not lost. Here are some options:
If possible by any means, simply install the latest stable version of Java on the machine.
From a computer that has JRE/JDK installed (or through another form of access to the JavaCompiler, AKA JavaC), recompile the code to the older version of Java using the command-line parameters for source and target java versions (Note: I am unsure if the JRE/JDK for the older version must be installed in the machine or not).
For this case, you might want to take a look at this and/or this.
Choose another language to work with, and re-do your code into that language; You can't run Java code without Java, the same way you can't travel by train without the train to travel with.
This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
How can I convert my java program to an .exe file ?
I'd like to create a Windows .exe for a Java program. Previously, I've used JEXECreator for this, but it's not entirely satisfactory because:
The executable sometimes works on the machine on which it was created but not on others.
The program is commercial; if you use the trial version, it adds a nag screen to your application.
I don't need the generated .exe to work if Java is not installed on the target machine (in fact, I think this is impossible).
Any recommendations?
Launch4j perhaps? Can't say I've used it myself, but it sounds like what you're after.
Most of the programs that convert java applications to .exe files are just wrappers around the program, and the end user will still need the JRE installed to run it. As far as I know there aren't any converters that will make it a native executable from bytecode (There have been attempts, but if any turned out successful you would hear of them by now).
As for wrappers, the best ones i've used (as previously suggested) are:
JSmooth
and
Launch4j
best of luck!
If you really want an exe Excelsior JET is a professional level product that compiles to native code:
http://www.excelsior-usa.com/jet.html
You can also look at JSMooth:
http://jsmooth.sourceforge.net/
And if your application is compatible with its compatible with AWT/Apache classpath then GCJ compiles to native exe.
I used exe4j to package all java jars into one final .exe file, which user can use it as normal windows application.
You could try exe4j. This is effectively what we use through its cousin install4j.
The Java Service Wrapper might help you, depending on your requirements.
If Java is installed on the target machine, there is no need to create an .exe file. A .jar file should be sufficient.