Question

I have a simple Swing app compiled with netbeans 7.1.2 on a ubuntu machine which has the java version:

java version “1.6.0_22” OpenJDK Runtime Environment (IcedTea6 1.10.4)
(6b22-1.10.4-0ubuntu1~11.04.1) OpenJDK Server VM (build 20.0-b11,
mixed mode)

jar works great when i use the shell using “java -jar filename.jar” in linux but in
the windows 7 with the java version 1.7.05 i get:
“Error: could not find or load main class”

How do i resolve this issue?

Answer 1

This error usually shows up when you don’t include the current directory (.) in the classpath.

If there are any external libraries that you specify when starting the program, then you probably do something like java -jar -classpath dir/library.jar program.jar. Instead, add . to the classpath: java -jar -classpath .;dir/library.jar program.jar

Other possibilities are:

• you didn’t include a Manifest in the JAR
• in the Manifest that you did include, you didn’t specify which is the main class, or you did it wrong.