mtov

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

class Subject {
  private List<Observer> observers = new ArrayList<Observer>();
  
  public void addObserver(Observer observer) {
    observers.add(observer);
  }

mtov

class Logger {
  private Logger() {}          // proíbe clientes de chamar new Logger()‏
  
  private static Logger instance;           // instância única da classe
  
  public static Logger getInstance() {
    if(instance == null)        // primeira vez que chama-se getInstance
      instance = new Logger();
    return instance;
  }

mtov

interface Channel {
   void send(String msg); 
   String receive();
}

class TCPChannel implements Channel {
   public void send(String m) {
      System.out.println("Enviando via TCP > " + m);
   }
   public String receive() {

mtov

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;

import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.ASTVisitor;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.MethodDeclaration;