java-interdependency-null-bug.java

java-interdependency-null-bug.java

public class Basket{
  private List<LineItem> lineItems = ...

  public List<Product> getProductsOfType(String type){
    List<Product> products = new ArrayList<Product>();
    for(LineItem item : lineItems){
      if(item.getProductType().equals(type)
        products.add(item.getProduct());    
    }
    return products;
  }

  public Product getHandset(){
    List<Product> handsets = getProductsOfType("handset");
    if(handsets.size() > 0)
      return handsets.get(0);
    return null;
  }
 
  public boolean hasHandset(){
    return (getHandset() != null);
  }

}