Kody źródłowe/Adapter (wzorzec projektowy)

Adapter klasowy

Java

/**
 * przykład w języku Java
 */

/* klasa użytkownika powinna tworzyć obiekty adaptera */
/* przy użyciu referencji tego typu */
interface Stack<T>
{
    void push (T o);
    T pop ();
    T top ();
}

/* klasa adaptowana */
class DList<T>
{
    public void insert (DNode pos, T o) { ... }
    public void remove (DNode pos) { ... }
  
    public void insertHead (T o) { ... }
    public void insertTail (T o) { ... }
  
    public T removeHead () { ... }
    public T removeTail () { ... }
  
    public T getHead () { ... }
    public T getTail () { ... }
}

/* adaptuj klasę DList opakowując ją w interfejs Stack */
class DListImpStack<T> extends DList<T> implements Stack<T>
{
    public void push (T o) {
        insertTail (o);
    }
  
    public T pop () {
        return removeTail ();
    }
  
    public T top () {
        return getTail ();
    }
}

Python

class Adaptee1:
    def __init__(self, *args, **kw):
        pass
 
    def specific_request(self):
        return 'Adaptee1'
 
class Adaptee2:
    def __init__(self, *args, **kw):
        pass
 
    def specific_request(self):
        return 'Adaptee2'
 
class Adapter(Adaptee1, Adaptee2):
    def __init__(self, *args, **kw):
        Adaptee1.__init__(self, *args, **kw)
        Adaptee2.__init__(self, *args, **kw)
 
    def request(self):
        return Adaptee1.specific_request(self), Adaptee2.specific_request(self)
 
client = Adapter()
print client.request()

Adapter obiektowy

Java

/**
 * przykład w języku Java
 */
class LegacyLine
{
    public void draw(int x1, int y1, int x2, int y2) {
        System.out.println("line from (" + x1 + ',' + y1 + ") to (" + x2 + ',' + y2 + ')');
    }
}
 
class LegacyRectangle
{
    public void draw(int x, int y, int w, int h) {
        System.out.println("rectangle at (" + x + ',' + y + ") with width " + w + " and height " + h);
    }
}
 
interface Shape
{
    void draw(int x1, int y1, int x2, int y2);
}
 
class Line implements Shape
{
    private LegacyLine adaptee = new LegacyLine();

    public void draw(int x1, int y1, int x2, int y2) {
        adaptee.draw(x1, y1, x2, y2);
    }
}
 
class Rectangle implements Shape
{
    private LegacyRectangle adaptee = new LegacyRectangle();

    public void draw(int x1, int y1, int x2, int y2) {
        adaptee.draw( Math.min(x1, x2), Math.min(y1, y2), 
                      Math.abs(x2 - x1), Math.abs(y2 - y1) );
    }
}
 
public class AdapterDemo
{
    public static void main(String[] args) {
        Shape[] shapes = { new Line(), new Rectangle() };
        // A begin and end point from a graphical editor
        int x1 = 10, y1 = 20;
        int x2 = 30, y2 = 60;
        for (Shape shape : shapes)
            shape.draw(x1, y1, x2, y2);
    }
}
//line from (10,20) to (30,60)
//rectangle at (10,20) with width 20 and height 40

Python

# Python code sample

class Target:
    def request(self):
        pass

class Adaptee:
    def specific_request(self):
        return 'Hello Adapter Pattern!'

class Adapter(Target):
    def __init__(self, adaptee):
        self.adaptee = adaptee
 
    def request(self):
        return self.adaptee.specific_request()

client = Adapter(Adaptee())
print client.request()