interfaces in Java

Question

In C#, it's common to have methods like this:

public IPerson GetPerson()
{
  // do stuff
  return new Person(..);
}

where "IPerson" is an interface used by Person, SpecialPerson, etc. In other words, although the method above returns a Person, a strategy pattern could be implemented such that a SpecialPerson is returned in lieu of a Person, provided they all use the IPerson interface.

Is this sort of thing possible in Java?

Answer 1

Yes. Java has interfaces too.

Answer 2

I believe it is pretty much the same, other than Java uses the "implements" keyword for interfaces.

Answer 3

Yes, Java has interfaces just like C#: public interface IPerson { ... }

Answer 4

The Java equivalent would be:

public Person getPerson()
{
  // do stuff
  return new SpecialPerson(..);
}

Where Person is a Java interface (prefixing interface names with the letter "I" is a convention from COM programming, thus not appropriate for Java).

Answer 5

Yes, it's pretty much the same... For example:

// Interface
public interface IPerson {
    public String getName();
}

// Implementation of interface - NB "implements" keyword
public class Person implements IPerson {
    private final String myName;

    public Person(String name) {
        myName = name;
    }

    public String getName() {
        return myName;
    }
}

// Method returning interface
public IPerson getPerson(String name) {
    return new Person(name);
}