I have some code in Java using Eclipse and I would like to deploy it to unix envirnment. The program is simple console program that just takes some arguments at the run time, read a file and print out some results.
My question that what is best approach to deploy and run it in unix envirnment. I was just thinking to copy all the classes file to the unix envirnment and create a batch file to run the main class file. Does this sound okay? Or, should I create a runnable jar file?
Also, where should i put the jar files that the prgram is referencing (in classpath)?
Thanks
I think an executable jar file will solve your purpose here.
You should be able to execute it as
java -jar <jarfilename> <arguement1> <arguement2> .... <arguementN>
You can execute the jar file from the current directory itself, just make sure your jar file has executable permissions.
chmod +x <jarfilename>
ls -la
Designing for easy deployment is important in my opinion.
In our case, there are some components:
store project in the source code management system (git). we break down source code as
the developing source code to dev branch
the stable source code to release branch
use build tool, such as ant or maven, and provide a deploy script in the project. (we will talk deploy script in 3.).
provide deploy script to:
fetch the latest stable source code in the build server
build to executable files in the build server (whatever you do)
send the package to the target server
launcher (close the old app and run the new app) in the target server (via remote ssh command)
Currently, you think how to package the java, but it is a simple thing just about building and runing. When you talk about deployment, make it as easy as possible. Each time we deploy just to invoke the release script.
PS. I don't like the executable jar. Using un-packaging jars and compiled class can be sending by rsync very efficiently.
It sounds Ok and will work for you. Just one fix: you are going to write shell script for unix, not batch file.
But you can do better. Typically java classes are packaged into jar file. Jar file is just a zip file with optional META-INF, directory, MANIFEST.MF and other stuff. So it is better to package your application into jar and then run it as: java -cp yourjar.jar YourMainClass.
To create jar file you can use any tool that can create zip or utility jar that is a part of your JDK. You can also create automatic build using ant, maven, gradle, bildr etc that will help you to package your application.
I would do the following:
create a dedicated directory for this program. Copy the dependent .jar files to that directory
write a (short) script that sets the classpath to point to these jars and then executes the main class
Given the above, it's largely a matter of style as to whether you create a runnable .jar or not. It'll be hidden from the user.
I'm suggesting a script because:
you can set regularly used JVM parameters easily (memory options etc.)
it's a pain (and hardly intuitive) to type java -jar {pathtojar} etc.
By copying the jars to a dedicated directory, you can then use different versions of jars for different scripts (e.g. you may have 2 programs that use two different versions of commons-lang)
You should also (probably) use this script to explicitly determine which version of Java you use to run the program with. As you install/upgrade you don't want to break your programs and the scripts can be configured to explicitly tie down this info.
I find this quickest of all:
First, create a jar, copy to unix server and change file permission just as dopplesoldner mentioned below.
You can put your library classes and or jar dependencies in a lib folder
Then execute the jar
java -Djava.ext.dirs=lib/ -classpath yourJar.jar com.yourPackage.yourClass
yourClass will be the class having main(String args[]) method you wanted to execute.
Related
I'm trying to create a rpm package for an executable jar generated using izpack. It's basically an installer wizard that allows a user to install a tool/software. It provides an executable jar. So we have to do
Java -jar file.jar
To initialize the wizard. I'm trying to automate it in Linux by creating an rpm that takes this jar and an sh file that executes this jar and runs the sh file when I execute the rpm file. I'm new to rpmbuild and all the tutorials online are about copying a particular jar from the rpm file to a target location not about how to execute it.
Can someone provide me a sample spec file which does the following
Creates an rpm file with .jar and .sh
When rpm -i file.rpm is executed, it runs the .sh file which in turn executes the jar and opens the wizard.
I'm open to any other suggestions on how to make jar auto execute. I'm basically trying to create an exe similar file for linux
Thanks in advance.
I highly recommend not doing this for various reasons, because it is the exact opposite of what RPMs are supposed to do. You should instead do the installation process on a build machine (as a non-root user!) and then capture the files to be installed.
Why is your approach a bad idea?
Installation script is hidden from the user (they cannot just query the RPM scriptlet to see what changes, beyond files, you made to their system)
The final installed files won't be controlled in any way, e.g. you won't be able to verify if they had been corrupted (rpm -V) or query what package installed them (rpm -q --whatprovides /path/to/file)
"Removing" or "Upgrading" the package won't actually do anything unless you write detailed scripts to handle all these unknown files
All the other reasons I didn't list as why you use a package manager instead of blindly distributing tarball distributions like we did in the dark ages
That said, if you insist on breaking things, your solution is to put the java installation call in %post, which will execute after the files have been installed. It will call it again when you upgrade the package, so the other installer needs to handle that. But again, this is not the right approach.
I have finished writing a project in the IntelliJ IDEA using Java. I can not figure out how to get the project from a saved file in the IDEA to an executable on my computer (I am on Windows 10 if that matters). Then, I want to be able to put the executable on my Girlfriend's computer (mac) because it's a gift for our anniversary. She's not very tech-savvy (apparently neither am I...) so I want to be able to just drag and drop something onto her desktop and have her be able to double click it and have it work without having to install anything to her computer. (I was looking at Jar files, but something I read said that mac's do not run Jar files unless I install some things).
So what I'm really asking is:
1)Using IntelliJ, how do I finalize my project (make a JAR file)? I have been unable to find directions for this that have actually worked.
2)What file do I need to make a batch file call to get it to run my program once it is a JAR? Does it just call the JAR as a whole, or a specific .class? (Someone suggested a bash file, but I have not heard of this before, so I am open to other suggestions besides batch files. I am currently looking into what bash files are)
3)Can I make the batch file call the file indicated in question 2 via relative path, thus allowing me to keep it in the JAR or in a folder with the JAR and making a shortcut to it on a desktop (for example)?
Building a JAR in IntelliJ
Option 1 - Long way round, getting IntelliJ to build your JAR
Hit Ctrl+Shift+Alt+S to open your Project Structure settings menu.
Go to Artifacts
Click the green +
Select JAR > Empty.
Name your JAR, for example Gift
Right click on all the files in the Available Elements that you want to put into your JAR (often everything) and select Put into Output Root
Click Apply. Click OK.
Go to Build > Build Artifacts... > Build.
You'll find your JAR in out/artifacts/{JAR_NAME}/{JAR_NAME}.jar
Option 2 - Short way (Maven only)
If you're using a dependency manager like Maven and you've adhered to the Maven project structure, just use the command:
> mvn clean package
and you'll find your JAR in your target/ directory.
In either option, you may have to define your .class file that contains your main() method.
Running a JAR
The normal way to run a JAR file would be to go into cmd (Windows) or a terminal (Mac & Linux) and use the command:
> java -jar {JAR_NAME}.jar {args}
where {JAR_NAME} is the file name of your JAR and {args} are any arguments that need to be defined up front.
If you want to not use a command line you could write a script that runs the JAR for you. Then you can double-click/run the script and it runs the JAR for you.
For Windows
I'd recommend writing a simple .bat or "batch" script that will run the file for you.
Keep the batch script in the same directory as your JAR file and just have it contain:
java -jar ./{JAR_NAME}.jar {args}
You could use a Powershell script or something similar though.
For Mac/Linux
As Mac (and Linux) are Unix systems we can use a .sh or "bash" script to run the JAR. Again keep the bash script in the same directory as your JAR file and use:
#!/bin/bash
java -jar ./{JAR_NAME}.jar {args}
.bat script is exclusive to Windows systems, .sh scripts are exclusive to Unix systems.
Because Windows and Unix are two very different systems, you're not going to find an executable file that works for all systems.
Converting your JAR into an executable
You could convert your JAR into a standard Mac "app" application bundle by following some instructions here.
However, I wouldn't recommend this as it isn't really necessary when you have a simple script/command option and for this method, you'd most likely need access to a MacOS machine with development tools.
My program runs exactly as it should when I run it out of eclipse, but when I try to build it into a runnable jar I get problems.
When I set Library Handling to Extract required libraries into generated JAR, or Copy required libraries into a sub-folder next to the generated JAR, the program runs but doesn't do anything that involves the external libraries. When I set it to Package required libraries into generated JAR, absolutely nothing happens when I try to run the JAR.
At this point I have no idea what to do after spending the past hour looking online for solutions, library handling seems to work fine for everyone else?
I'm using eclipse 4.4.1 if it makes a difference
First check to make sure you have the libraries. To do so open up the jar file with win rar or something similar. If the libraries are missing you can just copy and paste them into the jar file.
If they are there then you can create a batch file (If using windows) to run your jar file with the java command. Doing this will give you a console in command prompt to view output and stack-traces. This can help you find where the problem is.
Command for .bat file:
java -jar jarfile.jar
If you don't want to create a batch file and run it from command prompt, remember to make the cmd path the same as the jar file location.
First, I did look through the list of suggested questions generated by the keywords in my question but did not find anything relevant or helpful.
New to Java programming (not new to programming) so I don't know what useful tools there might be out there. I have a java console app, written using the intellij IDE. After testing and debugging, I am ready to deploy for a demo. Didn't find anything in the IDE that would let me do this!
I would now like to create a couple of installers - one for windows and one for linux. What do I do? I gather I just need the classfiles, but it would be nice to create an icon which would call the app with the right commandline options for the java.exe. As well, I have dependencies on log4j and jnetpcap (.dll requirements there)... how do I handle getting those support libs deployed - can I use the same installer or do I install them separately?
First things first, you need to JAR those class files. This is the standard way to package files in Java. A typical command would be:
jar cvf MyApp.jar *.class
Next you need to add a manifest to the JAR indicating the entry point into your program. Create a file called manifest.txt and add this line:
Main-Class: MyApp
MyApp would refer to the class name that contains the main() method. Now make the JAR again, this time specifying the manifest:
jar cvfm MyApp.jar manifest.txt *.class
On Windows, you can look into using Launch4J. You can use it to wrap your JAR in a EXE and specify that it runs as a non-GUI, console app.
In Linux, you can include a shell script along with your JAR to execute it. Place the script in your path. For example:
#!/bin/bash
java -jar MyApp.jar
It would be additional work to add dependent libraries to the mix as well as create installers. Seems too broad to include all in one question, but hopefully this will get you started.
I just completed working on a client's tool, which uses Jfreechart jar, and dll and a lib file for JNI interface. Now I would like to export/ provide a executable file to client, I tried to click on java project folder and export Java>Runnable Jar file (extract required libraries into generated JAR) , a Jar file is exported with some Warnings. However, we are not able to run the file on client's machine. How can I fix this, obviously I don't want to provide complete Java project and ask client to run from and IDE. Please provide me inputs.
Since Java is a cross-platform environment, it doesn't really have "executable files" like EXEs or anything. Instead, you run your .jar file with the Java runtime. For example:
C:\>java.exe MyProgram.jar
Of course some operating systems will just do this for you once the Java runtime is installed.
There are some programs to convert .JAR to .EXE, but I believe they just compile a thin wrapper that calls into the Java runtime.