Can't open .Jar file

[dabbedoom]

Hi

I have had problems to open jar files for a long time and decided first now to get some help with it. I am trying to assign more memory to a program called '' Spoutraft '', another version of Minecraft. But to even try to do that I need to open a jar file so I can start installing the launcher.

I am trying ot open it by double-clicking and also tried the CMD. All it says is '' Could not find the main class: C:\Users\Daniel Schnell\Desktop\Spoutcraft.jar. Program will exit. ''

Any suggestions how to fix this? I have tried to open with both javaw and java, nothing works.

Thank you in advance!

[Norm]

If the jar file contains an application intended to run when you enter the command: java -jar <JARFILE>.jar
then it will have a manifest file listing what class is to be executed first.
If the jar contains an applet to be executed in a browser, it does not use the manifest file. The <APPLET tag has a CODE= attribute that specifies what the starting class is.

What is in the jar file and how is it to be executed?

Open the jar in a zip file utility and see if it has a manifest file and see what is in that file.