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jar does not open java swing form

RosyCross
RosyCross Member Posts: 45
edited Sep 14, 2018 6:20AM in New To Java

Hi,

I am a learner.

I am using Java 8.

I have been working through some tutorials and have successfully built a number of moderately complex projects.

The tutorial I followed for the jar was this

https://www.javatpoint.com/how-to-make-an-executable-jar-file-in-java

I have followed it precisely and double checked every element.

My question is this, I am generating a .jar by creating a .MF file which identifies the main class and find that in some cases it works, calling the main works in the same way as running manually from command line, but in other cases it doesn't - I just get a brief progress on the cursor and then nothing happens.

MF FIle Content

-----------------------

Main-Class: PBCSControl

Some of the 'does not work' is java swing forms, but some of the swing forms do.

All of the swing forms work okay when manually run from command line.

I do not see any error, log file etc either when creating the jar or when running the jar.

Is there anything I can do to diagnose why it is not working for me, or anything special that I need to do to generate the jar file for a swing project?

edit: I found this by manually invoking the jar from command line instead of double clicking the file; -

c:\Java\BusinessContinuity>java -jar PBCSControl.jar

Exception in thread "main" java.lang.NoClassDefFoundError: PBCSControl$1

        at PBCSControl.main(PBCSControl.java:204)

Caused by: java.lang.ClassNotFoundException: PBCSControl$1

        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)

        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)

        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

        ... 1 more

I don't understand why it is not class defined error, when I can run the .java file manually?

Best Answer

  • Teresa Modesta
    Teresa Modesta Member Posts: 313
    edited Sep 7, 2018 4:12AM Answer ✓

    Hi,

    I had similar on a client site where the local techies gave us such limited access that we could not use java as we should.

    A workaround we found was to call the jar via a .bat and use the .bat as the shortcut, the .bat explicitly pointing to the elements along these lines; -

    echo off

    "C:\Program Files\Java\jdk1.8.0_144\bin\java.exe" -classpath c:\Java\MyJavaJarIsHere;c:\Java\BusinessContinuity\MyJar.jar;lib/* MyJar

    This worked for me, I am sure it is far from best practise, it was a sub-optimal workaround adopted because of sub-optimal local IT...

    RosyCross

Answers

  • Teresa Modesta
    Teresa Modesta Member Posts: 313
    edited Sep 7, 2018 4:12AM Answer ✓

    Hi,

    I had similar on a client site where the local techies gave us such limited access that we could not use java as we should.

    A workaround we found was to call the jar via a .bat and use the .bat as the shortcut, the .bat explicitly pointing to the elements along these lines; -

    echo off

    "C:\Program Files\Java\jdk1.8.0_144\bin\java.exe" -classpath c:\Java\MyJavaJarIsHere;c:\Java\BusinessContinuity\MyJar.jar;lib/* MyJar

    This worked for me, I am sure it is far from best practise, it was a sub-optimal workaround adopted because of sub-optimal local IT...

    RosyCross
  • RosyCross
    RosyCross Member Posts: 45
    edited Sep 14, 2018 6:19AM

    Thank you, this worked for me also!

This discussion has been closed.