Diseño Orientado a Objetos

class X {

}

class Y extends X {
public void m() {
  // aaaaaaaaaaaa
  // yyyyyyyyyyyy
  // bbbbbbbbbbbb
}

}

class Z extends X {
public void m() {
  // aaaaaaaaaaaa
  // zzzzzzzzzzzz
  // bbbbbbbbbbbb
}

}

class X {
public void m() {
  // aaaaaaaaaaaa
  this.middle();
  // bbbbbbbbbbbb
}

public abstract middle();
}

class Y extends X {
public middle(){
  // yyyyyyyyyyyy
}

}

class Z extends X {
public middle(){
  // zzzzzzzzzzzz
}

}

class Todo {

 private Parte parte;

 public Todo() {
   this.parte = new Parte();
 }

 public void m4(){
   ...
   this.parte.m1();
   this.parte.m3();
   ...
 }

 public void m5(){
   ...
 }

 public void m1(){
   ...
   this.parte.m1();
   ...
 }

 public void m2(){
   ...
 }

}

class Parte {
 public Parte() { ... }
 public void m1() { ... }
 public void m2() { ... }
 public void m3() { ... }
}

class Base {
 public Base() { ... }
 public void m1() { ... }
 public void m2() { ... }
 public void m3() { ... }
}

class Descendiente extends Base {

 public Descendiente() {
   super();
 }

 public void m4(){
   ...
   this.m1();
   this.m3();
   ...
 }

 public void m5(){
   ...
 }

 public void m1(){
   ...
   super.m1();
   ...
 }

 public void m2(){
   ...
 }

}

class PigPile {
 private Pig[] pigs;
 private int top;
 private int size;

public PigPile(int size){
  this.pigs = new Pig[size];
  this.top = 0;
 }

 public void push(Pig pig){
  assert pig != null;
  assert this.top+1 < this.pigs.length
  this.pigs[this.top] = pig;
  this.top++;
 }

public Pig pop(){
  assert this.top>0;
  this.top--;
  return this.pigs[this.top];
 }

public boolean empty(){
  return this.top==0;
}

}

class Pig {
...
}

PigPile pigs = new PigPile(3);

class WishPile {
 private Wish[] wishes;
 private int top;
 private int size;

public WishPile(int size){
  this.wishes = new Wish[size];
  this.top = 0;
 }

 public void push(Wish wish){
  assert wish != null;
  assert this.top+1 < this.wishes.length
  this.wishes[this.top] = wish;
  this.top++;
 }

public Wish pop(){
  assert this.top>0;
  this.top--;
  return this.wishes[this.top];
 }

public boolean empty(){
  return this.top==0;
}

}

class Wish {
...
}

WishPile wishes = new WishPile(1000);

class Pile<E> {
 private E[] items;
 private int top;
 private int size;

public Pile(int size){
  this.items = new E[size];
  this.top = 0;
 }

 public void push(E item){
  assert item != null;
  assert this.top+1 < this.items.length
  this.items[this.top] = item;
  this.top++;
 }

public E pop(){
  assert this.top>0;
  this.top--;
  return this.items[this.top];
 }

public boolean empty(){
  return this.top==0;
}

}

class Pig {
...
}

Pile<Pig> pigs = new Pile<Pig>(3);

class Wish {
...
}

Pile<Wish> wishes = new Pile<Wish>(1000);

class OneReport {

private Element[] elements;
private OneChecker checker;

public OneReport(Element[] elements){
  this.elements = elements;
  this.checker = new OneChecker();
}

public void generate() {
  ...
  for(Element element : this.elements){
    if (checker.isChecked(element)){
      ...
    }
  }
  ...
}

}

class OneChecker {
  boolean isChecked(Element element){
    return ...
  }

}

class OtherReport {

private Element[] elements;
private OhterChecker checker;

public OtherReport(Element[] elements){
  this.elements = elements;
  this.checker = new OhterChecker();
}

public void generate() {
  ...
  for(Element element : this.elements){
    if (checker.isChecked(element)){
      ...
    }
  }
  ...
}

}

class OtherChecker {
  boolean isChecked(Element element){
    return ...
  }

}

class Report {

private Element[] elements;
private Checker checker;

public Report(Element[] elements, Checker checker){
  this.elements = elements;
  this.checker = checker;
}

public void generate() {
  ...
  for(Element element : this.elements){
    if (checker.isChecked(element)){
      ...
    }
  }
  ...
}

}

interface Checker {
  boolean isChecked(Element element);
}

class OneChecker extends Checker {
  boolean isChecked(Element element){
    return ...
  }

}

class OtherChecker extends Checker {
  boolean isChecked(Element element){
    return ...
  }

}

class Report {

private Element[] elements;
private Checker checker;

public Report(Element[] elements){
  this.elements = elements;
}

public void set(Checker checker){
  this.checker = checker;
}

public void generate() {
  ...
  for(Element element : this.elements){
    if (checker.isChecked(element)){
      ...
    }
  }
  ...
}

}

interface Checker {
  boolean isChecked(Element element);
}

class OneChecker extends Checker {
  boolean isChecked(Element element){
    return ...
  }

}

class OtherChecker extends Checker {
  boolean isChecked(Element element){
    return ...
  }

}

class Profesor {
public void calificar(Secretaria secretaria){
  secretaria.setCalificación(10);
}
}

class Alumno {
public void matricular(Secretaria secretaria){
  secretaria.getCalificación(7);
  secretaria.setIngresosFamiliares(7, 666);
}
}

class Secretaria {
private Expediente expedientes[];

public void setCalificación(int id, int calificacion){
  ...
}
public int getCalificación(int id){
  ...
}
public int setIngresosFamiliares(int id, int cantidad){
  ...
}
public int getIngresosFamiliares(int id){
  ...
}
}

class Profesor {
public void calificar(SecretariaProfesorado secretaria){
  secretaria.setCalificación(10);
}
}

class Alumno {
public void matricular(SecretariaAlumnado secretaria){
  secretaria.setIngresosFamiliares(7, 666);
}
}

class SecretariaProfesorado {

private Secretaria secretaria;

public SecretariaProfesorado(Secretaria secretaria){
  this.secretaria = secretaria;
}
public void setCalificacion(int id, int calificacion){
  this.secretaria.setCalificacion(id, calificacion);
}
public int getCalificacion(int id){
   this.secretaria.getCalificacion(id, calificacion);
}
}

class SecretariaAlumnado {

privareturnte Secretaria secretaria;

public SecretariaAlumnado(Secretaria secretaria){
  this.secretaria = secretaria;
}
public int setIngresosFamiliares(int id, int cantidad){
  this.secretaria.setIngresosFamiliares(id, cantidad);
}
public int getIngresosFamiliares(int id){
  return this.secretaria.getIngresosFamiliares(id, cantidad);
}
}

class Secretaria {
private Expediente expedientes[];

public void setCalificación(int id, int calificacion){
  ...
}
public int getCalificación(int id){
  ...
}
public int setIngresosFamiliares(int id, int cantidad){
  ...
}
public int getIngresosFamiliares(int id){
  ...
}
}

class Profesor {
public void calificar(SecretariaProfesorado secretaria){
  secretaria.setCalificación(10);
}
}

class Alumno {
public void matricular(SecretariaAlumnado secretaria){
  secretaria.setIngresosFamiliares(7, 666);
}
}

interface SecretariaProfesorado {
public void setCalificación(int id, int calificacion);
public int getCalificación(int id);
}

interface SecretariaAlumnado {
public int setIngresosFamiliares(int id, int cantidad);
public int getIngresosFamiliares(int id);
}

class Secretaria implements SecretariaProfesorado, SecretariaAlumnado {
private Expediente expedientes[];

public void setCalificación(int id, int calificacion){
  ...
}
public int getCalificación(int id){
  ...
}
public int setIngresosFamiliares(int id, int cantidad){
  ...
}
public int getIngresosFamiliares(int id){
  ...
}
}

class Copier {

private KeyboardReader reader;
private PrintWriter writer;

public Copier(){
  this.reader = new KeyboardReader();
  this.writer = new PrintWriter();

public void copy(){
  ...
  char[] data = reader.read();
  ...
  writer.write(data);
  ...
}

}

class KeyboardReader{
public char[] read(){
  ...
}
}

class PrintWriter{
public  write(char[]){
  ...
}
}

class Copier {

 private Reader reader;
 private Writer writer;

 public Copier(){
   StreamFactory streamFactory = new StreamFactory();
   this.reader = streamFactory.getReader();
   this.writer = streamFactory.getWriter();
 }

 public void copy(){
   ...
   char[] data = reader.read();
   ...
   writer.write(data);
   ...
 }

}

class StreamFactory {

 public Reader getReader(){
   return ...
 }

 public Writer getWriter(){
   return ...
 }

}

interface Reader {

 char[] read();
}

class KeyboardReader implements Reader{

 public char[] read(){
   ...
 }

}

interface Writer {

 void write(char[]);
}

}

class PrintWriter implements Writer{

 public  write(char[]){
   ...
 }

}

class Button {

 private Lamp lamp;

 public Button(Lamp lamp){
   this.lamp = lamp;
 }

 void detect(){
   boolean buttonOn = this.getPhysicalState();
   if (buttonOn) {
     this.lamp.turnOn();
   } else {
     this.lamp.turnOff();
   }
 }

 boolean getPhysicalState(){
   ....
 }

}

class Lamp {

 public void TurnOn(){
   ...
 }

 public void TurnOff(){
   ...
 }

}

interface Button {

 void detect();
}

class ButtonImplementation implments Button {

 private ButtonClient client;

 public ButtonImplementation(ButtonClient client){
   this.client = client;
 }

 void detect(){
   boolean buttonOn = this.getPhysicalState();
   if (buttonOn) {
     this.client.turnOn();
   } else {
     this.client.turnOff();
   }
}

 boolean getPhysicalState(){
   ....
 }

}

interface ButtonClient {

 void TurnOn();
 void TurnOff();
}

class Lamp extends ButtonClient {

 public void TurnOn(){
   ...
 }

 public void TurnOff(){
   ...
 }

}