If you do not explicitly code any constructors, the compiler automatically creates a default constructor : Constructor « Object Oriented « SCJP

1. SCJP
2. Object Oriented
3. Constructor

//For compiler generated default constructor, 
//it has public access if the class is public; otherwise its access mode is default.

public class MainClass {
  public static void main(String[] argv) {
    MyClass my = new MyClass();
    System.out.println();
  }
}

class MyClass {
}