4. Command pattern //class Stock

public class Stock { 

 private String name; private double price; 

 public Product(String name, double price) { this.name = name; this.price = price; } 

 public void buy(int quantity){ System.out.println(BOUGHT:  + quantity + x  + this); } 

 public void sell(int quantity){ System.out.println(SOLD:  + quantity + x  + this); } 

 public String toString() { return Product [name= + name + , price= + price + ]; } 

} 

a. Create two command classes that allows the customer to buy and sold stocks. b. Write a main method to test it.

5. Adapter pattern //interface NameInterface interface NameInterface { public void setName(String n);

public String getName(); }

//Adaptee class class SimpleName implements NameInterface { String name;

public void setName(String n) { name = n; }

public String getName() { return name; } }