Executing .jar files with a double click - java

I've been using Eclipse as my Java IDE and today I ran into an interesting problem. I used the built in file>export>runnable jar file to create a jar file for one of my programs. It runs perfectly if I start it from the command line/with a batch file, but doesn't run from a double click. I made absolutely certain that .jar files are associated with javaw and it still didn't work. It isn't a huge problem I absolutely NEED fixed, but if anyone has any ideas I'd love to hear them.
Update: I tried using Aram Kocharyan's solution (see answer below). No luck. It seems to be just this one .jar file too. All other jars launch with a double click. Rebuilding the jar doesn't help. :P

I wrote a short guide on this a while back you might find helpful:
http://ak.net84.net/projects/how-to-make-a-multi-platform-executable-java-jar-file/
This will work on double click in windows without setting any additional settings, and I've tested it with the Jar Launcher on Mac and it doesn't complain.

open your jar with..javaw
which is in bin folder of jre... in my computer it is #
C:\Program Files\Java\jre\bin\javaw.exe

Put this inside a .bat:
start javaw -classpath "%~dp0YOU-JAR-NAME.jar" -Djava.library.path="native" foo.package.bar.YourClassWithMainMethod
the option -Djava.library.path="native" its not required for run, i include this because one reason for using a .bat instead do a double click on a .jar is to use JVM-parameters, in my case i need this parameter for my project run.
the %~dp0 part get current directory

Related

How to make my jar file executable by double click to open terminal

Okay so basically, every time I've seen this question asked it doesn't have the answer I'm looking for which is why I'm trying to ask myself.
Basically, I made a java project on BlueJ (required by school, sadly. But I can export it elsewhere if that's the problem (preferably IntelliJ or Visual Studio Code)), but essentially, I want to make it so I can simply double click my .jar export and it will open a terminal window and launch. When I try this however, I get this error: First Error
And when I click Ok then this appears:
Second Error
Now, if I want the jar to run on terminal, doing java -jar jarFileName.jar works perfect, but what I want is for that to happen when I double click the jar file; for it to launch and run from the terminal.
All the other answers I've seen for this problem blame the users computer and usually tell them to install some version of java or whatever, but this isn't the problem. I have other jar files that I can run perfectly fine, like Minecraft Forge installer or Minecraft Spigot installers (sorry only examples are Minecraft, not much else uses Java). And also this was for a uni project and no one else in my field know how to get their jar to be executable, nor does this file work for anyone else.
So yeah, I know it's a problem with how the jar was compiled or something and not what java is installed my PC.
I just want to make it double-clickable for the convenience of when I send it to friends, but if anyone knows another way I can get around this problem then that's fine. For example I know I could make a Bash file which simply does the java -jar jarFileName.jar for me or something, but I'd rather have it all as one jar file, so I don't know if this can be incorporated into the file but yeah.
Also I'd really like a solution which doesn't involve downloading external programs or whatever, since all I want to do is send this file to my friends and have them just double click it to launch.
TL;DR, what do I have to do to make my jar file actually executable by double clicking it. Thank you.
To make a jar file executable you have to set the entrypoint
You can do this by passing the e option to the jar command when you create the jar file, for example:
jar cvfe myapp.jar com.mycompany.myapp.MyApp com\mycompany\myapp
This will add the Main-Class entry in the jar's manifest pointing to the startup class, which should have a main method, for example:
package com.mycompany.myapp;
public class MyApp {
public static void main(String[] args) {
// start up the application
}
}
When you create a JAR file, it automatically receives a default manifest file. There can be only one manifest file in an archive, and it always has the pathname
META-INF/MANIFEST.MF
The entrypoint is specified by the Main-Class, for example:
Manifest-Version: 1.0
Created-By: 1.8.13_37 (Oracle Corporation)
Main-Class: com.mycompany.myapp.MyApp
If you want to make an existing jar file executable you could unzip it, modify the manifest and zip it again (and rename it so it has the .jar extension - a jar is just a zip).
But I think the errors you show are not caused by the jar not being executable, but by some environment issue, causing the Java application to not find the necessary variables or paths to make the Java Native Integration (JNI) work. To solve this you would have to provide more detail on what you are trying to do with JNI.

Running .jar File Java 8

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.

Java application will run from CMD and Eclipse but not double click

I've done a search and I can see that a lot of people have had the same problem as me, but none of the solutions have worked for me.
Basically I have a Java Project in Eclipse that is from my old Windows Installation. I've cleaned and rebuilt it because at first it wouldn't compile, but now I have it exported as a Runnable Jar. However, the only way I can get the application to appear is to do java -jar foo.jar in command prompt, or run it in Eclipse. If I double click the JAR in Windows Explorer nothing happens even though I know that Java is associated correctly because other Runnable Jars work.
The project only has the x86 JRE listed in it's Build Path Libraries and all the files listed appear to exist. I'm running Windows 7 HP.
Update: I'm sorry, but I just discovered that no other Runnable Jars are working either. If they are wrapped with launch4j they work though...
Edit: The Runnable Jars that I export from Eclipse do work fine on other systems and load on double click
Some registry values or file associations are probably messed up. Wiping off all of your existing JRE's and JDK's and re-installing them should fix your issue.
Alternatively you may be able to fix it by manually editing the registry value here:
HKLM > SOFTWARE > Classes > jarfile > shell > open > command
My value is
Type: REG_SZ
Data: "C:\Program Files\Java\jre8\bin\javaw.exe" -jar "%1" %*
You'd of course want that path to point to your javaw.exe, and make sure you have the additional arguments.
I was also facing the same problem while i was working with Spring tool suite.
You may use the following steps:-
Right click on project -> export -> Runnable jar file -> (Here,In library handling,there are three options,you have to choose middle one i.e package required library into generated jar.It will package external dependency also).
-In my case, my runnable jar was only executing on my environment i.e on which i have created that JAR. Initially i have selected the first option to create JAR i.e extract required libraries into required JAR.but that was not proper.
It may help you.Let me correct if i am getting wrong.
Since you are able to run the JAR running the command line, I believe your issue is related to which version of Java is set to run the file when it is double-clicked.
To find out which version is successfully running the file from the command line and set it to open JAR files by default:
Open a new command prompt window.
Run echo %path%. Among the path values, you should be able to find one pointing to the bin folder of one of the installed versions of Java. Copy this path somewhere.
Navigate to the JAR file you would like to run. Right click the JAR -> Open with -> Choose default program... -> Browse...
Browse to the path you copied in step 2. (the easiest way is to paste it into the address bar)
Double click javaw.exe.
Click OK.
You should now be able to run the JAR file. Please let me know if your problem persists.
I have made a jar with and keep it on desktop.Then,I double clicked on the jar and it working fine for me.
How I and what I have monintored: In my main class, perform some operation and at the end I add on Thread.sleep(25000); to hold the program for few moments. After every double click on the exported jar I found one new javaw.exe process added in the system process tree. I have noticed it on Task manager. and after 25000ms respective javaw.exe process ended. As my application does not cointain any GUI that's why I have not seen any GUI changes for the respective process. I'm Confident that if my application have some GUI, I will surely get the respective GUI window on every run.
Common mistakes : when we export a project from Eclipse as Runnable JAR file, it is exported with selected Eclipse launch configuration and Eclipse specific launch wrappers. Now if the configuration does not match when you are trying to run it via double-click you will not be able to see the error, If you run it from CMD then surely you will get the error log.
To create standard executable JAR file : To create a standard executable JAR file, you can export as JAR file and specify the main class in last screen of the wizard.
That's working for me fine. I used the same jar from different system and keeping it different location.

Generated Runnable jar: Could not find the main class

I've always used the Export -> Runnable jar option of Eclipse and it has worked perfectly, but today it seems that all the Runnable jars I create produce the following error when I run them: (Edit: run them by double clicking the file.)
Java Virtual Machide Launcher
Could not find the main class: (class). Program will exit.
I've tried everything for the past two hours, but it still doesn't work.
I can still run jars that I have created in the past without a
problem.
The manifest file looks exactly the same as in those jars
that work and all the .class files seem to be in place...
I've tried exporting with Package required libraries into generated jar but the file still doesn't work. It doesn't show the error though - double clicking the file does nothing.
Edit: Running the jar file through the cmd works perfectly, but simply double clicking on it yields this error. (Bragboy)
Edit 2:
Contents of a manifest file from a jar that works: (Obviously they're the same, just wanted to avoid confusion.)
Manifest-Version: 1.0
Class-Path: .
Main-Class: defender.DefenderComponent (+ two empty lines afterwards)
And contents of a manifest file from a jar that doesn't work: (When opening the file directly)
Manifest-Version: 1.0
Class-Path: .
Main-Class: pixel.Entry (+ two empty lines afterwards)
Both main class files are confirmed to be at their respective locations.
While exporting the jar file, it is important to specify which is the main class. You can do this in the eclipse wizard. To get to this screen, you need to simply export as just a jar as opposed to Runnable jar.
One more option to find out the error, try to open a command prompt (in windows) or a terminal (in linux/mac) and give this command java -jar your_jar.jar . this will show a detailed error on what is happening.
Since your jar works properly when launched via command prompt, the definite culprit would be the default program opening for .jar extension in windows. To avoid this, you should probably have to right click on the jar and try open with a jar executable that is compatible with the java version that you ran the same from the command prompt.
In the end the only thing that fixed this was to switch from JRE 1.7 down to JRE 1.6.
I know this is a bit of a thread necro, but I was having the same problem. What finally worked for me was fixing my %JAVA_HOME% path in environment variables. Turns out it was still pointing to a 1.6 release, and that's why nothing since I installed 1.7 was running except through Eclipse where I had fixed all the references to point to the correct release.

no output when .jar is executed

I built an application in Netbeans 6.8 and made project.jar file. When I run it, it works only on my computer, but not on any other computer. However, when I made any simple application, that doesnt use any libraries, it works fine on any computer.
Is there any way, how to invoke some error message, where is the problem?
My project use R 2.9.2, so I install this version on other computer and set the System Path variable exactly same. Other libraries listed in lib directory are: AbsoluteLayout.jar,DatePicker-V0.99-2006.09.01.jar,jcommon-1.0.16.jar,jfreechart-1.0.13.jar,jmathplot.jar,JRI.jar,pdf-renderer-1.0.5.jar
Thank you
You don't get any message at all? What do "works" and "not works" look like?
You sound like another person who hasn't taken the time to learn how to do things by hand on the command line without an IDE. I'd recommend doing that. Open a command shell and type in the java -jar -cp ... foo.jar command to run your stuff. The messages you get back will be educational.
Note the -cp command line argument. That's how you add your JARs to the CLASSPATH properly.
I solved this problem as follows, maybe it will help someone.I add 2 paths in PATH system variable:
Start -> Control Panel -> System -> Advanced
Click on Environment Variables, under System Variables, find PATH, and click on it.
In the Edit windows, modify PATH by adding the location of the class to the value for PATH.
you must add both paths, to jri.dll and r.dll, in my case it were these:
C:/Program Files/R/R-2.9.2/bin/;C:/Program Files/R/R-2.9.2/library/rJava/jri/;
I have added these lines already, but with different different slash. So be careful, you must use it / not \ to define path!!!

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