Eclipse IDE can't proceed java application

Question

I am using eclipse 2020-03 and write a simple code here.

HelloWorld.java

public class HelloWorld{

  public static void main(String[] args){
    System.out.println("Hello World!");
  }
  
  
}

However when I will try to execute it or click the play button on the designer, this will came out:

And if I try to select java application the run button is disabled.

Any suggestion/help TIA

Answer 1

Just do what the window tells you to: "Press the 'New Configuration' button". It's.. the blank page with the plus sign in the corner, just as the window is showing you. THEN you can configure whatever you want. Alternatively, right click on any class file that has a main in it, and in the context menu, 'Debug' will show up. (There's almost no reason to even use run, debug gives you hot code replace and you can, well, debug, if you want to. If you set no breakpoints, you won't notice anything).