Interface Segregation Principle- Program to an interface

Question

I was reading about SOLID and other design principles. I thought ISP was the same as \"Program to an interface, not an implementation\". But it looks like these are differen

Answer 1

1. IWorker Interface:

   public interface IWorker {
       public void work();
       public void eat();
   
   }
   

2. Developer Class :

   public class Developer implements IWorker {
   
        @Override
        public void work() {
              // TODO Auto-generated method stub
              System.out.println("Developer working");
   
        }
   
        @Override
        public void eat() {
              // TODO Auto-generated method stub
              System.out.println("developer eating");
   
        }
   
   }
   

3. Robot Class:

   public class Robot implements IWorker {
   
        @Override
        public void work() {
              // TODO Auto-generated method stub
              System.out.println("robot is working");
   
        }
   
        @Override
        public void eat() {
              // TODO Auto-generated method stub
              throw new UnsupportedOperationException("cannot eat");
   
        }
   
   }
   

For a more complete example go here.