I made a small game in Java.
It had about 5 different classes and the main class being in Game.java
I compiled it into a jar file and I did everything correctly with my manifest.txt which gives the name of the file where the main class is in.
The jar file worked on my computer so I then converted it into an exe file and sent it to someone else.
When My friend tries to run the exe file, it gives him an error saying:
Could not find main class game. Now exiting.
The exe and jar file work fine on my computer but not on a different computer.
We both also run Windows 7.
What went wrong?
I think you need to have every library used in your application beside your EXE file in lib folder. interestingly enough, when lib files are missing, the error shown is about main class, which is so not the case ;) anyway, I had the same problem and got it resolved by including lib folder beside my exe file. this is part of readme.txt generated by net-beans in dist folder, that might be helpful to you:
======================== BUILD OUTPUT DESCRIPTION
when you build an Java application project that has a main class, the
IDE automatically copies all of the JAR files on the projects
classpath to your projects dist/lib folder. The IDE also adds each of
the JAR files to the Class-Path element in the application JAR files
manifest file (MANIFEST.MF).
Related
I've run .jar files before, but I've encountered a "different" situation, and I'm not sure what to do. I'd appreciate if someone could help me out.
Previously, I programmed with Java 6 and Eclipse Juno exported all my programs to runnable jar files. I'd get a .jar file that I could run by just double clicking on it. The files always looked something like this (note the jar file icon):
Recently, I wrote a program in Java 8 with Eclipse Luna (Release 4.4.0) and exported it to a runnable jar file, and I got something different (note the different file icon):
It no longer runs when I double click it. Instead, my computer uncompresses the jar, as it would a zip file. I tried running it from terminal. I cd'd to the directory and typed
java -jar graph3D.jar
I got the following error message:
Error: Unable to access jarfile graph3D.jar
After uncompressing the jar file, I found a folder named META-INF with the manifest file, MANIFEST.MF in it. It was the only file that seemed to resemble an executable file. Do I have to do something with that?
Could someone explain how I can run the second jar file graph3D.jar? Is it something new with Java 8, or something different about Eclipse Luna, or something else?
(Both programs run fine in Eclipse, by the way)
Thanks for your time and help.
Edit:
Below was the dialog box Eclipse displayed if anyone is interested.
Selecting "Use .jar;.zip" makes the filename "graph3D.jar;.jar;*.zip" .
Selecting "Use .zip" makes the filename "graph3D.jar;*.zip"
Selecting "Cancel" doesn't let you go forward.
You'd have to manually delete the extra file extension.
Somehow when you exported the file, the filters for the file dialog box (*.jar;*.zip) got attached to the filename, which is graph3D.jar;*.jar;*.zip, not graph3D.jar. Java can't find it because it doesn't have the name you supplied. Rename the file and pay close attention next time you export; either you fat-fingered something, or you're triggering a significant bug that needs fixing.
I recommend that you will access the build folder after you've built your project on the IDE under your project folder (in your workspace) and copy both the libraries folder and the .jar and post them wherever you want the program to be "installed", you'll then have an executable jar that should run smoothly without problems, just as I said don't forget the lib folder.
I think there is nothing new in Java 8 related with the running jar, I guess you need to check the the Eclipse export issues, it seems your classes are missing from your second jar file.
I'll try to be clear and concise on this.
i have a jar file of a project which is working perfectly. Now I need to make some changes to the application so i extracted that jar using this command.
jar xf jwire.jar
the files extracted are
META-INF (containing manifest file)
Resources (containing pictures used in application)
Jwire (containg classes and java files)
.classpath
.project
manifest.mf (another manifest file with some other path to main class)
i also added two empty folders src and bin here on somebodys suggestion.
now i'm trying to create the jar file again using all these folders.
Without making any type of changes I'm trying to rebuild this jar using the following
jar cf newjar.jar G:\Project1\project
NOTE:- I am guessing it's the right way to build the file. Please point if it's not right.
G:\Project1\project is the path to above mentioned files and folders.
The jar created using this is of size 729kb while the earlier one had 711Kb and when I run it using the following command.
java -jar newjwire.jar
I get the following message
no main manifest attribute, in newjwire.jar
Next i tried extracting this newjwire.jar file in order to see its manifest file. I got this folder META-INF containing the MANIFEST.MF file. it didn't have the path to the main class , So I edited it and put the modified file back on using the following command
jar uf newjwire.jar META-INF/MANIFEST.MF
when I run this jar, I get the following message
Error: Ivalid or corrupt jarfile newjwire.jar
What am I doing wrong? Am I building the jar file the right way? I used eclipse juno too and it gave the same message to that mainclass is missing. There is a main class consisting the main function. Is this something has to do with My orignal jar having two MANIFEST file.
I hope the problem is understandable. Clear and detailed answers will be appreciated.
you're supposed to update JAR files by jar uf jar-file input-file(s)
see this link: http://docs.oracle.com/javase/tutorial/deployment/jar/update.html
According to this page you need to EITHER have Manifest.txt present when you create or update the JAR, or use the e option to specify the main class. Probably the latter would make more sense in your case.
jar cfe newjar.jar mypackage.MainClass G:\Project1\project
I've been working on a processing application using ControlP5 and Twitter4j. I want to have my project run from a single jar file from any operating system. Basically I want to package up my application. My application uses images. I've been browsing for more than an hour, but I cant find how to do this. Any suggestions?
using
processing 2
twitter4j3
Thanks in advance!
I dont know if you can directly do it from the Processing IDE however, if export your sketch to a Java applet then locate the .java the the sketch folder you can use this in conjunction with Eclipse to export to a jar file.
So, I know that this post is very old but if you are still looking for a solution, or to other people that see this thread, it's relatively simple.
Export the project
In the folder with the exported project (something like application.windows64), navigate to lib and find core.jar and project name.jar (you need to have file name extensions visible)
Rename the files to .zip files
Extract core.jar to whatever folder
Extract project name.jar into the same folder (make sure you don't do it into a subfolder)
Click yes if it asks if it wants you to replace a file (if it doesn't you extracted the files incorrectly)
Delete core.jar and project name.jar
If the project uses images, move them into the same folder as all the other files
Select all of the files in the folder, right click, hover over send to and select compressed (zipped) folder
Rename the .zip file to name of project.jar
This might be old, but i still find other posts about it on processing forums.
This is the best way to run processing project as a jar file.
When exporting application, you will always end up with a lib folder inside exported application(whether for Linux and Windows). For windows, open command prompt(or power shell), you can use right-click+shift and then click on open power shell here.
After that you can run the following command.
java -classpath lib\* DisplayDepthStream
Now DisplayDepthStream is the name of sketch file.
To explain the command, -classpath lib\* tells java to add everything under lib directory to the class path. And DisplayDepthStream is the name of my main class.
Hope this helps~!
Chears
I have a .java file that I created in eclipse. I managed to make a .jar out of it, but I don't know how to put my images folder into the jar, nor do I know how to make the jar run?
Should it run already, or would it just be an archive like a .zip?
Thank you guys so much for your help here, because I am completely and totally lost when it comes to this. I have been programming in java (just making .java files in JCreator basically) for about 2 years now.
I have searched and searched but never found a good answer. Anyone that can shed the like on how running .java files as an application and things work, that would be awesome.
P.S. I am using GUI, and the code is correct.
Thank you so much!
What is a runnable jar?
A jar is a archive (it uses the same file format of a ZIP) that contains program artifacts: compiled classes, images, configuration files and other resources.
To be a runnable jar it must contain a special file, called manifest (the manifest support electronic signing, version control, package sealing) with a Main-Class: project.name.EntryPoint entry that specifies the class that is the start point of the program.
This can be easily achieved by using the Eclipse feature File > Export > Java > Runnable JAR file.
How to run a runnable jar?
Using the command line, just do java -jar <jar_file_path>.
But nowadays the graphic shells of the operating systems (Windows Explorer / Gnome / KDE) already call java when you double-click a jar file.
How to put images on the .jar?
You can do this specifying on the Eclipse project that the images folder is also a source folder. Now when exporting the project to the jar file it will include them.
I have created an executable java Swing .jar application. It works fine on Windows. The application hierarchy is :
application.jar
images(Folder) .......... Contains all images the application uses.
libraries(Folder) ....... Contains all external jar libraries the application uses.
bundles(Folder) ......... Contains all bundle files the application uses.
database(Folder) ........ Contains the database files the application uses.
All the above folders exist outside the jar file. Now i am trying to create a Mac executable file (.app) from "application.jar" to run it on Mac so i used the "Jar Bundler" as specified here but when i run the output application.app file nothing happens, nothing runs and i can't even debug it.
I think the main reason is that it can't see the external folders. So is it impossible to create a .app file if the application has external folders ?
And is there a way to debug the .app file to see what's going on ?
Nothing runs, and i can't even debug it.
Diagnostic output from the launch process may be obtained as follows:
$ export JAVA_LAUNCHER_VERBOSE
$ ./YourApplication.app/Contents/MacOS/JavaApplicationStub
There's a related example here.
Most likely the problem is your working directory.
When you run an executable JAR file by double-clicking it, the working directory is the parent directory of the JAR file.
By default, the working directory of an application bundle is its parent directory. If you package the external folders into the application bundle they will be located under $APP_PACKAGE/Contents/Resources.
So the assumption about the working directory that you make for an executable JAR file does not hold for an application bundle.
In order to set the working directory to the resources directory, add
<key>WorkingDirectory</key>
<string>$APP_PACKAGE/Contents/Resources</string>
to the Info.plist file of your bundle.
In case you know nothing about application bundles, please read this document.
This might help: AppBundler by Josh Marinacci
I am not sure about your exact directory hierarchy. But on a Mac with Xcode installed is an application called "Jar Bundler". It exist for exact that purpose you are asking for.
BTW, Mac application use the suffix .app, that is right. But they are not files. Thery are directories.