Could not find or load main class Test Caused by: java.lang.ClassNotFoundException: Test

Question

I am new to Java. I just wanted to make a jar file from a java file and then run the jar file. The jar is created but when I run it, I encounter this error "Could not find or load main class MyTest Caused by: java.lang.ClassNotFoundException: MyTest"

The MyTest.java file was simply something like this:

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class MyTest {
    public static void main(String[] args) {
        ....
    }
}

My Manifest.MF file is like below:

Manifest-Version: 1.0
Main-Class: MyTest

And I created the jar file using jar cmvf Manifest.MF test.jar MyTest.java in command line.

Could anyone please help me?

After you edited the code in your question, does the problem still persist? — QBrute, Mar 29 '22 at 09:23
You need to compile your source file and put the resulting MyTest.class file in the jar. — tgdavies, Mar 29 '22 at 09:33
You need to add `MyTest.class` to the JAR (after compiling `MyTest.java`), not `MyTest.java`. — Mark Rotteveel, Mar 29 '22 at 13:50
@MarkRotteveel Thanks, yes that was the problem! I should have first compiled the java code using "javac Test.java" — nsh, Mar 29 '22 at 15:55

score 0 · Answer 1 · answered Mar 29 '22 at 09:38

This problem can be due a lot of causes.I have had it many times , most of the time it is because your classpath has non-english characters or spaces. Try to change your project to other directory. On the other hand if you use eclipse you may have more than one main and there are problems with that.

If you try what I have told you and still the problem persists, it will be a problem with the command.

Good luck.

Could not find or load main class Test Caused by: java.lang.ClassNotFoundException: Test

1 Answers1