public class LoadingFromWhere {
  public static void main(String args[]){
    LoadingFromWhere s = new LoadingFromWhere();
    s.doit();
    }

  public void doit() {
    System.out.println(this.getClass().getName() + " is loaded from " +
      getClass().getProtectionDomain().getCodeSource().getLocation());
    
    MyClass s = new MyClass();
    }
}

class MyClass {
  MyClass() {
    System.out.println
      (this.getClass().getName() + " is loaded from " +
       this.getClass().getProtectionDomain().getCodeSource().getLocation());
       }
  }

Другой способ :

public class FromWhere {
  public static void main(String args[]){
    Class theClass = java.lang.Object.class;
    java.net.URL u = theClass.getResource("");
    System.out.println("The Java RunTime used is located at : " + u);
    
    theClass = FromWhere.class;
    u = theClass.getResource("");
    System.out.println("This class (FromWhere) is located at : " + u);
    }
  }