Question

I am new to java. I write a simple code like this:

import java.io.*;


public class a
{
    public static void main(String []argc)
    {
        System.out.println("S");
    }
}

I compile it with below bash command:

javac a.java

then this:

java a

But it said:

Could not find or load main class a

My java version is 1.6.0.
What should I do?

Answer 1

A common reason for this is that you’ve set the environment variable CLASSPATH.

This is usually not a good idea, because that setting always influences your whole system.

You can easily define a per-instance classpath, by specifying the -cp parameter.

In your case you can do

java -cp . a

This tells Java to look for classes in the current directory (.).