Java jar running

Question

Any idea why

java -jar jarname.jar

works, but double clicking the jar gives a

"Could not find the main class:"

error? Manifest is correctly placed and double clicking was working until recently, but all of a sudden it gives that error. I'm not sure what changes I made though.

EDIT:
The command I used to create the jar was (in cmd):

jar cfe jarname.jar files.Main *

Main is part of the package files.

See http://stackoverflow.com/questions/10875839/jar-file-keeps-giving-me-could-not-find-the-main-class-program-will-exit and http://stackoverflow.com/questions/8629412/generated-runnable-jar-could-not-find-the-main-class — Suresh Kumar, Jun 13 '12 at 04:15

score 1 · Answer 1 · answered Jun 13 '12 at 03:58

1

Add this entry in your manifest file:

Main-Class: com.abc.def.YourMainClass

Hope this'll help!

answered Jun 13 '12 at 03:58

HashimR

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Did you made this jar using IDE? – HashimR Jun 13 '12 at 04:02
Did you write fully qualified name of your `MainClass` in manifest file? – HashimR Jun 13 '12 at 04:09
What do you mean by fully qualified? – user1102901 Jun 13 '12 at 04:10
The full class name, including the package name. Like if my main class is `HelloWorld.class` then i would write something like this: `com.xyz.HelloWorld`. – HashimR Jun 13 '12 at 04:12

score 0 · Answer 2 · answered Jun 13 '12 at 04:19

Some time ago I had a comparable problem. And it was caused by multiple JDK/JRE versions on my machine. What is used by double-clicking differs from what is used by typing jar in a shell.

I think JarFix could help. Or you lookup what is associated with double-click in the file-associations (reinstall java might also help)

score 0 · Accepted Answer · answered Jun 13 '12 at 04:23

0

It seems to have been some weird compiler version problem. When I complied the class files using an older version of java, then compiled it into a .jar file, it was able to run.

answered Jun 13 '12 at 04:23

user1102901

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Java jar running

3 Answers3