“Could not find or load main class” Error while running java program using cmd prompt [duplicate]

Answer 1

I was facing similar issue but it was due to space character in my file directory where I kept my java class.

Scenario given below along with solution:

   public class Sample{
      public static void main(String[] args) {
        System.out.println("Hello world, Java");
      }
}

• My Sample.java class was kept at Dir "D:\Java Programs\Sample.java"[NOTE: Package statement not present in java class].
• In command prompt, changed directory to "D:\Java Programs\", my programmed compiled but failed to run with error "Could not find or load main class"
• After all the possible solutions over SOF(nothing worked), I realized may b space causing me this issue.
• Surprisingly removal of folder name space char['Java Programs' -> 'JavaPrograms'], my program executed successfully.
  
  Hope it helps

Answer 2

I removed bin from the CLASSPATH. I found out that I was executing the java command from the directory where the HelloWorld.java is located, i.e.:

C:\Users\xyz\Documents\Java\javastudy\src\org\tij\exercises>java HelloWorld

So I moved back to the main directory and executed:

java org.tij.exercises.HelloWorld

and it worked, i.e.:

C:\Users\xyz\Documents\Java\javastudy\src>java org.tij.exercises.HelloWorld

Hello World!!

Answer 3

I was getting the exact same error for forgetting to remove the .class extension when running the JAVA class. So instead of this:

java myClass.class

One should do this:

java myClass