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Named Method Injection

Overview

This is where a component has an empty constructor with dependencies passed in via setters and matching done via the method name (after ‘set’). Matches are against named components.

public class FruitBasket { 
  public void setOrange(String orange) { 
    ... 
  } 
  public void setPear(String pear) { 
    ... 
  } 
  public void setBanana(String banana) { 
    ... 
  } 
  // other methods 
}

Usage

pico = new DefaultPicoContainer(new NamedMethodInjection();
pico.addConfig("orange" , new Seville());
pico.addConfig("pear" , new Bartlett());
pico.addConfig("Banana" , new Cavendish());
pico.addComponent(FruitBasket.class); // etc 
FruitBasket basket = pico.getComponent(FruitBasket.class);

Yes that’s right, there’s no constructor needed. It means that for a Unit Test, you cannot simply ‘new’ the class without some lines of code to populate the dependency fields via setters.

The component factory for this is a class NamedMethodInjection . It only handles named-method injection for components.