Prototype Pattern

Specify the kind of objects to create using a prototypical instance, and create new objects by copying this prototype.

Participants

• Prototype: declares an interface for cloning itself
• ConcretePrototype: implements an operation for cloning itself
• Client: creates a new object by asking a prototype to clone itself

Code

public class Main {

    public static void main(String[] args) {
        ConcretePrototype1 p1 = new ConcretePrototype1("I");
        ConcretePrototype1 c1 = (ConcretePrototype1) p1.clone();
        System.out.println("Cloned: " + c1.getId());

        ConcretePrototype2 p2 = new ConcretePrototype2("II");
        ConcretePrototype2 c2 = (ConcretePrototype2) p2.clone();
        System.out.println("Cloned: " + c2.getId());
    }
}

public abstract class Prototype {
    private String id;

    public Prototype(String id) {
        this.id = id;
    }

    public String getId() {
        return id;
    }

    public abstract Prototype clone();
}


public class ConcretePrototype1 extends Prototype {

    public ConcretePrototype1(String id) {
        super(id);
    }

    @Override
    public Prototype clone() {
        return new ConcretePrototype1(getId());
    }
}

public class ConcretePrototype2 extends Prototype {

    public ConcretePrototype2(String id) {
        super(id);
    }

    @Override
    public Prototype clone() {
        return new ConcretePrototype2(getId()) ;
    }
}

Output

Cloned: I
Cloned: II

eidherjulian61 / design-patterns

Main Design Patterns

eidher ・ Sep 27 '20 ・ 1 min read

#designpatterns #creational #structural #behavioral