Java - Problem with Jar

juror

I finished developing a program in the Eclipse IDE, so I exported it to a Jar file. My computer intially opened up the Jar file using winzip, so i changed the default program to open it with to Java (TM) Platform SE Binary.
Now when I double click on the icon, the timer glass shows for about 1-2 seconds and then thats it, nothing else happens. I can't get my program to open up outside of my IDE.

If anyone could help I would greatly appreciate it.

Thanks.

Hobbes

what do you get when you run it from the command line?

lynchie

juror wrote: »

I finished developing a program in the Eclipse IDE, so I exported it to a Jar file. My computer intially opened up the Jar file using winzip, so i changed the default program to open it with to Java (TM) Platform SE Binary.
Now when I double click on the icon, the timer glass shows for about 1-2 seconds and then thats it, nothing else happens. I can't get my program to open up outside of my IDE.

If anyone could help I would greatly appreciate it.

Thanks.

Its not going to run by double clicking on it without adding a Main-Class element to the manifest file before exporting it as a jar file.

juror

I ran it from the command line, and again nothing happens. The command prompt just re-appears.

I set the entry point in Eclipse. This was done in the Exporting wizard. It resulted in the following Mainfest file being generated and included in the jar,

Manifest-Version: 1.0
Main-Class: gui.Main

lynchie

What are the contents of the jar file. I assume your main class is called Main.class and its in the gui package? If so, the contents of the jar file should be similar to the following

jar -tvf myjar.jar

xxx xxx xxx xxx xx xx xx META-INF/manifest.mf
xxx xxx xxx xxx xx xx xx gui/Main.class

pauldiv

Sounds like a bad build. If you have Netbeans you could try importing the project, clean and rebuild it. Netbeans then creates a deployment directory under the main project folder that includes java libs, a manifest and an executable jar etc. It works a treat.

juror

pauldiv wrote: »

Sounds like a bad build. If you have Netbeans you could try importing the project, clean and rebuild it. Netbeans then creates a deployment directory under the main project folder that includes java libs, a manifest and an executable jar etc. It works a treat.

I just tried that, but I have gotten the same result.
I do use a mysql connector, would this have anything to do with it?

juror

If this helps, I had been running it from the command line by simply typing the name of the jar

RecycleProgram1.jar

But recently i tried this

java -jar RecycleProgram1.jar

and the follwing exception occurred

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at database.DatabseConnection.createDBConnection(DatabseConnection.java:30)
        at database.DatabaseController.<init>(DatabaseController.java:91)
        at database.DatabaseController.<clinit>(DatabaseController.java:86)
        at gui.Main.loadData(Main.java:26)
        at gui.Main.<init>(Main.java:18)
        at gui.Main.main(Main.java:37)
Exception in thread "main" java.lang.ExceptionInInitializerError
        at gui.Main.loadData(Main.java:26)
        at gui.Main.<init>(Main.java:18)
        at gui.Main.main(Main.java:37)
Caused by: java.lang.NullPointerException
        at database.DatabaseController.createStatements(DatabaseController.java:105)
        at database.DatabaseController.<init>(DatabaseController.java:92)
        at database.DatabaseController.<clinit>(DatabaseController.java:86)
        ... 3 more
 

Might this mean there is something missing from my Manifest file in realtion to the DB driver?

Hobbes

you need the classpath to your mySQL set up on the machine so that it can see the related jar files for that.

Your not going to be able to make a self executing jar file. But you can make a CMD/SH file file and run that.

will be something like...

java -cp <path to required jars> -jar RecycleProgram1.jar

juror

Hobbes wrote: »

you need the classpath to your mySQL set up on the machine so that it can see the related jar files for that.

Your not going to be able to make a self executing jar file. But you can make a CMD/SH file file and run that.

will be something like...

java -cp <path to required jars> -jar RecycleProgram1.jar

Brilliant! It works. Thanks very much for the help, and to everyone else who contributed.

I created a .bat file to run the command above and it worked a treat.
Thanks again