Interface

All interface classes are by default Public and Abstract, and do not contain any completed methods.

Interface should implement (complete the body of a method) when all the abstract methods are inherited from the superclass (abstract class).

The actual use of interface will be structuring (setting or mandating to set off rules).

An example of a Java program with an interface

The following is an example of an interface in a Java program:

package MyFirstPackage;

interface sample_abs2 {
  void abstr_method ();
  void abstr_method1();
}

abstract  class sample_abs3 implements sample_abs2 {
  abstract void abstr_method2 ();

  void abstr_method2A(){
    System.out.println("Abstact class abstr_method2A");
  }
}

class Interface extends sample_abs3 {//implements is a keyword used to complete the
//Interface Class
  public void abstr_method () {
    System.out.println("Interface abstr_method implementation");
  }

  public void abstr_method1 () {
    System.out.println...