Quick ways to open/execute .jar file

Open and view the source
Change the .jar to .zip, click yes to the warning message, then you can open it as a zip file.
Execute by command line: java -jar fileName.jar
Need runtime environment

Create a bat file. New a txt file and paste code:

@echo OFF
cd jarFilePath
java -jar fileName.jar

Then change .txt to .bat, double-click it.